CN117070962A

CN117070962A - Apparatus and method for generating nitric oxide

Info

Publication number: CN117070962A
Application number: CN202311031041.2A
Authority: CN
Inventors: 封志纯; 毛雯; 张煜彦; 耿翔; 陈涛; 赵杨波; 吴清
Original assignee: Nanjing Nuoling Biotechnology Co ltd
Current assignee: Nanjing Nuoling Biotechnology Co ltd
Priority date: 2020-12-18
Filing date: 2021-12-17
Publication date: 2023-11-17
Also published as: CN117802515A; CN115398036B; CN115398036A; CN117568825A

Abstract

The present disclosure provides an apparatus for generating nitric oxide. The device comprises: a reaction chamber having a liquid region configured to contain a reaction medium and a gas region configured to contain a product gas comprising nitric oxide; a plurality of electrodes disposed in the reaction medium; an energy source electrically connected to the plurality of electrodes and configured to apply a predetermined voltage or a predetermined current to the cathode to generate nitric oxide; a sparger disposed in the reaction medium; an inlet circuit in fluid communication with the sparger and configured to deliver a carrier gas to the sparger; an outlet circuit in fluid communication with the gas region of the reaction chamber and configured to deliver a product gas from the reaction chamber; a first circulation loop for circulating a first fluid flow relative to the reaction chamber, the first circulation loop comprising a first inlet in fluid communication with the gas region of the reaction chamber, a first outlet in fluid communication with the sparger, and a first pump, the first pump generating a first fluid flow from the first inlet to the first outlet.

Description

Apparatus and method for generating nitric oxide

The present application is a divisional application of patent application CN202180027930.4 (the filing date of the original application is 2021, 12 months and 17 days, and the name of the present application is devices, systems and methods for generating nitric oxide).

Cross Reference to Related Applications

The present application claims priority rights of chinese patent application No.202011502839.7, chinese patent application No.202011502846.7, chinese patent application No.202011502862.6, chinese patent application No.202011508948.X, chinese patent application No. 20202304800. X, chinese patent application No.202023072485.5, chinese patent application No. 2020237503. X, chinese patent application No.202110183873.0, chinese patent application No.202120353644.4, chinese patent application No.2021, chinese patent application No.202120353650.X, chinese patent application No.2021, chinese patent application No.20212, chinese patent application No.202023072485.5, chinese patent application No.20212, chinese patent application No. 8625, chinese patent application No.2021, no. 2022, chinese patent application No. 20235 3650.

Technical Field

The present disclosure relates to devices, systems, and methods for generating and/or delivering nitric oxide, and more particularly, to devices and methods for generating and/or delivering nitric oxide on demand.

Background

Nitric Oxide (NO) is a gas signaling molecule that plays an important role in many physiological and pathological processes. NO can diffuse through the cell membrane without an intermediate transport mechanism and thus can signal neighboring cells or tissues in an efficient and rapid manner. For example, NO produced by vascular endothelial cells may signal relaxation to surrounding vascular smooth muscle, resulting in vasodilation and increased blood flow. NO may also be involved in electron transfer and redox reactions in biochemical events in human cells. NO can cause various physiological effects, such as endothelial dependent vasodilation, by activating guanylate cyclase.

Inhalation of NO can increase the oxidative capacity of the body and reduce the need for high risk in vitro cardiopulmonary support in critically ill patients. Controlled administration of appropriate amounts of inhaled NO can reduce pulmonary hypertension and improve oxygenation. The U.S. food and drug administration has approved inhalation of NO as a drug for the treatment of neonatal persistent pulmonary hypertension. NO inhalation therapy has also been used in various diseases or clinical medicine fields such as neonatal respiratory disorders, intensive care medicine, cardiothoracic surgery, acute respiratory distress and anesthesiology.

In a clinical setting, high pressure gas tanks or cylinders are used to provide NO. Such gas tanks are large in size and weight and are typically fixed on wheeled conveyors or carts, often placed at the bedside of a crowded intensive care unit. The use of such heavy and large gas tanks may present safety risks to the patient and the medical staff. For example, patients and healthcare workers may be exposed to toxic nitrogen dioxide formed during system setup or due to potential NO leakage from damaged regulators, valves, or supply lines. Medical personnel may also suffer physical injury from moving or changing cylinders. Accordingly, there is a need to overcome and/or address one or more of these disadvantages. The present disclosure relates to a system and method without a gas tank or "NO tank" that can generate NO on demand, without the need to store large amounts of pressurized NO.

Disclosure of Invention

According to some embodiments of the present disclosure, there is provided an apparatus for generating nitric oxide, the apparatus comprising: a reaction chamber having a liquid region configured to contain a reaction medium and a gas region configured to contain a product gas comprising nitric oxide; a plurality of electrodes disposed in the reaction medium, the plurality of electrodes comprising a cathode; an energy source electrically connected to the plurality of electrodes and configured to apply a predetermined voltage or a predetermined current to the cathode to generate nitric oxide; a sparger disposed in the reaction medium; an inlet circuit in fluid communication with the sparger and configured to deliver a carrier gas to the sparger; and an outlet circuit in fluid communication with the gas region of the reaction chamber and configured to deliver the product gas from the reaction chamber; and a first circulation loop configured to circulate a first fluid flow relative to the reaction chamber, the first circulation loop including a first inlet in fluid communication with a gas region of the reaction chamber, a first outlet in fluid communication with the sparger, and a first pump configured to generate a first fluid flow from the first inlet to the first outlet.

According to some embodiments of the present disclosure, there is provided another apparatus for generating nitric oxide, the apparatus comprising: a reaction chamber having a liquid region configured to contain a reaction medium and a gas region configured to contain a product gas comprising nitric oxide; a plurality of electrodes disposed in the reaction medium, the plurality of electrodes comprising a cathode; an energy source electrically connected to the plurality of electrodes and configured to apply a predetermined voltage or a predetermined current to the cathode to generate nitric oxide; a sparger disposed in the reaction medium; an inlet circuit in fluid communication with the sparger and configured to deliver a carrier gas to the sparger; and an outlet circuit in fluid communication with the gas region of the reaction chamber and configured to deliver the product gas from the reaction chamber; and a first circulation loop comprising a first inlet in fluid communication with the gas region of the reaction chamber, a first outlet in fluid communication with the sparger, and a first pump configured to generate a product gas stream from the first inlet to the first outlet; the first circulation loop is configured to recirculate a product gas stream relative to the reaction chamber; the sparger is configured to emit bubbles comprising a carrier gas into the reaction medium or to emit bubbles comprising a carrier gas and a product gas stream.

According to some embodiments of the present disclosure, there is provided a method for generating nitric oxide, the method comprising: applying a predetermined voltage or a predetermined current to one or more of a plurality of electrodes by an energy source to generate nitric oxide, the plurality of electrodes being disposed in a reaction medium contained in a reaction chamber, the plurality of electrodes comprising a cathode, the reaction chamber comprising a gas region and a liquid region, the liquid region being configured to contain the reaction medium, the gas region being configured to contain a product gas comprising nitric oxide; receiving a carrier gas through an inlet circuit in fluid communication with a sparger disposed in the reaction medium; emitting bubbles of the carrier gas in the reaction medium through the sparger to sweep a surface of one or more of the plurality of electrodes; circulating a first fluid stream in a first circulation loop relative to the reaction chamber, the first fluid stream comprising a product gas stream; and delivering the product gas from the reaction chamber through an outlet loop, the outlet loop being in fluid communication with a gas region of the reaction chamber.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments as claimed.

The accompanying drawings form a part of this specification. The accompanying drawings illustrate several embodiments of the present disclosure and, together with the description, serve to explain the principles of certain disclosed embodiments as set forth in the appended claims.

Drawings

Fig. 1 is a schematic diagram of an NO system according to some embodiments of the present disclosure.

Fig. 2 is a schematic diagram of an NO generating device according to some embodiments of the present disclosure.

Fig. 3A is a schematic view of a first electrode, a second electrode, and a sprinkler according to some embodiments of the present disclosure.

Fig. 3B is a perspective view of a sprinkler according to some embodiments of the present disclosure.

Fig. 4A is a graphical representation of the concentration of NO in a product gas generated by an NO generation device versus the current applied to an electrode, according to some embodiments of the present disclosure.

Fig. 4B is a graphical representation of the concentration of NO in a product gas generated by an NO generation apparatus over time, according to some embodiments of the present disclosure.

Fig. 4C is a graphical representation of the concentration of NO in a product gas generated by the NO generation apparatus during multiple phases, according to some embodiments of the present disclosure.

Fig. 5A is an exploded view of a filter device according to some embodiments of the present disclosure.

Fig. 5B is a cross-sectional perspective view of the filter device of fig. 5A.

Fig. 5C is a cross-sectional view of the filter device of fig. 5A.

Fig. 6A is a perspective view of a pressure vessel according to some embodiments of the present disclosure.

Fig. 6B is a cross-sectional perspective view of the pressure vessel of fig. 6A.

Fig. 6C is another cross-sectional view of the pressure vessel of fig. 6A.

FIG. 7A is a top perspective view of an exhaust treatment device according to some embodiments of the present disclosure.

Fig. 7B is a bottom perspective view of the exhaust treatment device of fig. 7A.

Fig. 7C is a cross-sectional view of the exhaust treatment device of fig. 7A.

Fig. 8A is an exploded view of a gas converter according to some embodiments of the present disclosure.

Fig. 8B is a schematic diagram of a gas converter according to some embodiments of the present disclosure.

Fig. 9 is a schematic diagram of a ventilation circuit for delivering NO to a patient according to some embodiments of the present disclosure.

Fig. 10A is a perspective view of a moisture collector according to some embodiments of the present disclosure.

Fig. 10B is a partial perspective view of the moisture collector of fig. 10A.

Fig. 10C is another partial perspective view of the moisture collector of fig. 10A.

Fig. 11A is a schematic diagram of a sampling process of a gas monitoring apparatus according to some embodiments of the present disclosure.

Fig. 11B is a schematic diagram of an initialization process of a gas monitoring apparatus according to some embodiments of the present disclosure.

Fig. 11C is a schematic illustration of a cleaning process of a gas monitoring apparatus according to some embodiments of the present disclosure.

Fig. 11D is a schematic diagram of a calibration process of a gas monitoring apparatus according to some embodiments of the present disclosure.

Fig. 12 is a flow chart illustrating a NO generation method according to some embodiments of the present disclosure.

Detailed Description

Reference will now be made in detail to the disclosed embodiments in connection with the accompanying drawings. Unless otherwise defined, technical or scientific terms have the meaning commonly understood by one of ordinary skill in the art. The embodiments disclosed are described in sufficient detail to enable those skilled in the art to practice the embodiments disclosed. It is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the disclosed embodiments. Accordingly, the materials, methods, and examples are illustrative only and are not meant to be necessarily limiting.

The present disclosure provides devices, systems, and methods for generating NO from one or more electrochemical reactions. According to one aspect of the present disclosure, an embodiment may output a product gas comprising NO. NO in the product gas may be generated or transported at a predetermined concentration and/or flow rate. For example, some embodiments may output a product gas having a clinically relevant concentration and/or flow rate of NO for inhalation of NO therapy. The concentration and/or flow of NO in the product gas may be adjusted. For example, the concentration of NO in the product gas may be in the range of about 0 to about 20000 ppm.

The dimensionless unit "ppm" used in the present disclosure to describe gas concentration refers to parts per million by volume and can be converted to other concentration units, such as parts per million moles or milligrams per liter (mg/L). The dimensionless units "%" or "vol%" used in the present disclosure to describe gas concentrations refer to volume percentages and can be converted to other concentration units, such as weight percentages or molar concentrations. As used herein, "about" in a numerical range means that the numerical range encompasses normal industry and subject matter variations or tolerances for manufacturing and/or operation. As used herein, the phrase "less than," "greater than," "between one value and another value," or "from one value to another value" in a range of values includes endpoints and all values within or between the endpoints.

According to another aspect of the disclosure, embodiments may allow for the generation of NO in a phase comprising at least one operating cycle. During the operating period, the concentration and/or flow of NO in the product gas may reach and/or remain at steady state. As described herein, the concentration and/or flow of NO in the product gas at steady state may deviate from a certain value or range due to steady state errors. For example, the steady state error may be in the range of about 0 to about 10%. The operating cycle may, for example, last up to about 60 hours or more.

According to another aspect of the disclosure, embodiments may allow NO to be generated in a phase comprising at least one ramp cycle. As described herein, a ramp period may refer to a transition period in which the NO concentration of the product gas may be increased or decreased from an initial concentration to a predetermined steady state concentration. The ramp period may be a ramp-up period or a ramp-down period. For example, the ramp period may range from about 2 minutes to about 10 minutes. The ramp period may be predetermined or adjusted to allow a more rapid or immediate provision of a steady NO flow, as may be required in an intensive care unit, for example.

According to another aspect of the disclosure, embodiments may allow NO to be generated in multiple phases. Multiple phases of NO generation may provide NO to treat the same patient or to treat different patients over time. One or more parameters for generating or delivering NO by some embodiments of the invention may be predetermined and/or adjusted. For example, the number of phases, the number of operating cycles in a phase, the start time and/or end time of an operating cycle, and/or the concentration and/or flow of NO in the product gas during an operating cycle of a phase may be predetermined and/or adjusted.

In accordance with another aspect of the present disclosure, to reduce exposure to health risks, embodiments may reduce or remove one or more toxic impurities, such as nitrogen dioxide, that may be present in the product gas.

Various devices, systems, and methods for generating NO consistent with the present disclosure are described below.

Fig. 1 is a schematic diagram of an NO system 10 according to some embodiments of the present disclosure. As shown in fig. 1, in some embodiments, the system 10 includes a NO generating device 100. The NO generating device 100 generates NO using one or more electrochemical reactions. In some embodiments, the system 10 includes a carrier gas source 200 disposed upstream of and in fluid communication with the NO generation device 100. The carrier gas source 200 may generate or supply the carrier gas 122. The carrier gas 122 may be supplied to the NO generating device 100 to transport the generated NO out of the NO generating device 100. For example, the carrier gas 122 may sweep, purge, and/or entrain generated NO from the NO generation device 100.

The NO generating device 100 may output NO generated in the product gas. The product gas may include one or more components. In some embodiments, the product gas comprises a carrier gas. The product gas may flow from the NO generation device 100 to one or more downstream systems or apparatuses. One or more downstream systems or devices may transport, process, and/or store the product gas from the NO generation apparatus 100. For example, the product gas may include one or more impurities, such as moisture, one or more toxic gases, and solid matter. In some embodiments, the system 10 includes one or more filtration systems or devices to reduce or remove one or more impurities in the product gas. In some embodiments, the system 10 includes a ventilation circuit to deliver NO to a patient with or without oxygen. Various embodiments of the system 10 and methods of using the system 10 to generate NO are described below.

Electrochemical generation of NO

Fig. 2 is a schematic diagram of an NO generating device 100 according to some embodiments of the present disclosure. NO-generating device 100 is configured to generate NO from one or more electrochemical reactions in reaction medium 112. As shown in fig. 2, in some embodiments, the NO generating device 100 includes a reaction chamber 102 and a plurality of electrodes. In some embodiments, the reaction chamber 102 includes a liquid region 108 and a gas region 110. Liquid region 108 is configured to receive reaction medium 112. Gas region 110 is configured to receive gases generated in and/or carried from reaction medium 112.

In some embodiments, the reaction chamber 102 has a first side 104 and a second side 106. The first side 104 may be a top side of the reaction chamber 102. The second side 106 may be a bottom side of the reaction chamber 102. The first side 104 and the second side 106 may extend parallel to each other. For example, the first side 104 may have a surface that extends parallel to a surface of the second side 106. The liquid region 108 may be disposed adjacent to the second side 106. The gas region 110 may be disposed adjacent to the first side 104.

As shown in fig. 2, in some embodiments, NO generating device 100 includes an inlet circuit 120 and an outlet circuit 124. The inlet circuit 120 is disposed downstream of and in fluid communication with the carrier gas source 200. In some embodiments, the inlet circuit 120 has at least one outlet 144, such as an opening, in the liquid region 108. The inlet circuit 120 may receive the carrier gas 122 and transport the carrier gas 122 to the liquid region 108. An outlet circuit 124 is disposed downstream of and in fluid communication with the gas region 110 of the reaction chamber 102. In some embodiments, the outlet circuit 124 has at least one inlet, such as an opening, in the gas region 110. For example, the carrier gas 122 may transport the generated NO from the gas region 110 out of the NO generating device 100 through an outlet loop 124.

In some embodiments, the NO generation device 100 may include one or more NO sensors (not shown) configured to detect the concentration of NO in the product gas. The NO sensor may be arranged in any suitable location. For example, the NO sensor may be disposed in contact with the product gas in the gas region 110. In some embodiments, the NO sensor is disposed in or near the outlet circuit 124 of the reaction chamber 102. For example, the NO sensor may be disposed at an opening of the outlet circuit 124, such as at an inlet or outlet of the outlet circuit 124. For example, the NO sensor may be disposed within a conduit of the outlet circuit 124. In some embodiments, the NO sensor may be disposed downstream of the outlet circuit 124 or downstream of one or more filters or filtering devices downstream of the outlet circuit 124. For example, as shown in fig. 1 and 2, the NO sensor 125 may be disposed downstream of a filter 506 of the filtration system 500 disposed downstream of the outlet circuit 124.

In some embodiments, the plurality of electrodes of the NO generating device 100 includes a first electrode 116 and a second electrode 118. First electrode 116 and second electrode 118 are disposed in reaction medium 112. In some embodiments, the second electrode 118 is a counter electrode to the first electrode 116. For example, the first electrode 116 may be a cathode and the second electrode 118 may be an anode, or vice versa. As described herein, while some embodiments in the present disclosure are described with respect to the first electrode 116, similar embodiments with respect to the second electrode 118 will be apparent to those skilled in the art. In some embodiments, the plurality of electrodes includes a reference electrode. The reference electrode may be the first electrode 116, the second electrode 118, or a third electrode (not shown). The reference electrode may be disposed in or external to reaction medium 112.

In some embodiments, as shown in fig. 2, the first electrode 116 and the second electrode 118 are electrically connected to the energy source 114. In some embodiments, the energy source 114 is configured to apply a voltage to the first electrode 116 or to create a potential difference between the first electrode 116 and the second electrode 118. In some embodiments, the energy source 114 is configured to apply a current to the first electrode 116 or to generate a current that flows from the second electrode 118 to the first electrode 116, and vice versa. The voltage or current applied to the electrodes may be predetermined and/or adjusted based on one or more conditions, such as a desired concentration and/or flow of NO in the product gas.

In some embodiments, the voltage applied to the first electrode 116 may be measured as a potential difference between the first electrode 116 and the second electrode 118 or between the second electrode 118 and the first electrode 116. In some embodiments, the current applied to the first electrode 116 may be measured as the current through the first electrode 116. In some embodiments, the voltage applied to the first electrode 116 may be measured as a potential difference between the first electrode 116 and a reference electrode or between the reference electrode and the first electrode 116.

In some embodiments, reaction medium 112 is a liquid. For example, reaction medium 112 may comprise an aqueous solution or an organic solution. In some embodiments, reaction medium 112 includes a nitrite ion source. In some embodiments, NO-generating device 100 generates NO by electrochemically reducing nitrite ions in reaction medium 112 to NO adjacent to and/or at the surface of an electrode (e.g., first electrode 116). In some embodiments, electrochemical reduction of nitrite ions to NO is promoted or achieved by one or more catalysts. In some embodiments, one or more catalysts are dissolved or dispersed in reaction medium 112. One or more catalysts may be adjacent to and/or in contact with the surface of an electrode (such as first electrode 116) to act, individually or collectively, as an electron transfer mediator between the surface of the electrode and nitrite ions in reaction medium 112.

In some embodiments, the catalyst may be immobilized on a surface of an electrode (such as first electrode 116). In some embodiments, the catalyst comprises one or more compounds selected from the group consisting of cystine, cysteine, methionine, thiophene, and derivatives thereof. For example, one or more catalysts may be covalently attached, adsorbed, doped, or covalently attached to a deposited material on the electrode, such as a polymer, film, or hydrogel. Some examples of materials that may be deposited on the electrodes may be found in PCT/US 2018/027081. As described herein, PCT/US2018/027081 is incorporated herein by reference for relevant subject matter discussed in this disclosure.

The catalyst may facilitate electrochemical reduction of nitrite ions in the reaction medium 112 to NO at and/or near the surface of an electrode (e.g., first electrode 116). In some embodiments, the catalyst comprises a metal-containing compound, such as a metal-ligand complex. In some embodiments, the metal-containing compound can facilitate electrochemical reduction of nitrite ions in reaction medium 112 to NO according to the following reaction:

m (first valence) (l) +e ^- Reaction 1. Fwdarw.M (second valence) (l)

M (second valence) (l) +NO ₂ ^- +2H ⁺ M (first valence) (l) +NO+H ₂ O reaction 2

Wherein M (l) represents a metal-ligand complex, M represents at least one metal ion, l represents at least one surrounding ligand or complexing agent, and NO ₂ ^- Indicating nitrite ions. NO can be generated by reducing at least one metal ion in the metal-ligand complex from a first valence to a second valence, a secondThe price is lower than the first price. The reduced metal-ligand complex acts as an intermediate in reducing nitrite ions in reaction medium 112 to NO while being oxidized to the original metal-ligand complex.

The at least one metal ion may for example comprise one or more metal ions selected from copper, iron, titanium, chromium, manganese, cobalt and nickel ions. The at least one surrounding ligand or complexing agent may comprise, for example, a ligand selected from the group consisting of tris (2-pyridylmethyl) amine (TPA or TPMA), 1,4, 7-triazacyclononane, 1,4, 7-trimethyl-1, 4, 7-triazacyclononane (Me) ₃ TACN), tris (2-aminoethyl) amine, 3- ((2-aminoethyl) amino) propionic acid, and bis (2-aminopyridine) propionic acid. Some other examples of metal ions or surrounding ligands or complexing agents are found in PCT/US 2018/027081.

In some embodiments, the use of a metal-ligand complex as a catalyst allows the use of cathodic voltage or cathodic current to generate NO and/or to regulate the generation of NO. In some embodiments, controlling the magnitude of the voltage or current applied to an electrode (such as first electrode 116) allows for controlling the ratio of reduced form of the metal-ligand complex to its oxidized form, e.g., at and/or near the electrode surface. This may allow for control of the amount and/or rate of NO generated in reaction medium 112 at a given concentration of nitrite ions and metal-ligand complex.

In some embodiments, an electrode (such as first electrode 116) may have any suitable shape including one or more surfaces. For example, the first electrode 116 may comprise a plate, sheet, or mesh. In some embodiments, NO is electrochemically generated from one or more electrochemical reactions occurring at and/or near one or more surfaces of the first electrode 116 when a cathodic voltage is applied to the first electrode 116, or when a cathodic current is applied to the first electrode 116. Some or all of the NO generated from the electrochemical reaction at and/or near the surface of first electrode 116 in reaction medium 112 may be transported out of reaction medium 112 and into gas region 110 of reaction chamber 102. For example, the carrier gas 122 may be used to sweep, purge, and/or entrain some or all of the NO generated from the reaction medium 112.

The energy source 114 may include one or more suitable power devices or circuits that allow for the application of a voltage or current to the electrodes, such as an electrical outlet, power circuit, dc power supply, ac power supply, generator, or energy storage device. The energy storage device may include, for example, one or more batteries or fuel cells. In some embodiments, the energy source 114 includes one or more electrical loops for controlling or regulating the voltage or current applied to the electrodes. In some embodiments, one or more of the electrical circuits may include a voltage regulator to control or regulate the voltage applied to the electrodes. In some embodiments, one or more of the electrical circuits may include a galvanostat to control or regulate the current through the electrodes.

In some embodiments, the polarity of the first electrode 116 and the second electrode 118 may be switched. For example, the polarity of the first electrode 116 and the second electrode 118 may be switched by reversing the polarity of the energy source 114, such as by reversing the polarity of the voltage or current from a DC power source using a reversing switching loop, or by using an AC power source. For example, the energy source 114 is an AC power source configured to apply a periodic alternating current or alternating voltage to the electrodes.

For example, the switching of the electrode polarity may be automatically controlled by the control loop according to a software program. Additionally or alternatively, the switching of the electrode polarity may be manually controlled by a user, for example by using a switch. The polarity of the electrodes may be switched during NO generation, between two operating periods or between two phases. NO in reaction medium 112 contacting or adjacent to the electrode may cause degradation of the electrode and may negatively affect NO generation efficiency. Switching the polarity of the electrodes may increase the effective surface area for NO generation and may increase the lifetime of the electrodes and/or the NO generating device 100.

The electrodes of the NO generating device 100, such as the first electrode 116, the second electrode 118 or the reference electrode, may be made of one or more materials. One or more electrodes of the NO generating device 100 may be made of the same material or different materials. In some embodiments, the electrodes of the NO generating device 100 comprise at least one electrically conductive material. The at least one conductive material may be a metallic or non-metallic material. The at least one conductive material may be selected from, for example, a group of conductive materials including platinum, palladium, gold, copper, brass, silver, carbon, glassy carbon, boron Doped Diamond (BDD), graphite, stainless steel, titanium, iridium, ruthenium, and one or more alloys thereof, such as ruthenium-iridium alloys.

In some embodiments, the electrode of the NO generating device 100 comprises at least one substrate. The at least one substrate may be a metallic or non-metallic material. The at least one substrate may be selected from, for example, a group of materials comprising silicon dioxide, conductive glass, tin-doped indium oxide, fluorine-doped indium oxide, conductive plastics, platinum, gold, copper, brass, silver, carbon, glassy carbon, boron-doped diamond (BDD), graphite, stainless steel, titanium, iridium, ruthenium, and one or more alloys thereof, such as ruthenium-iridium alloys. In some embodiments, the electrode of the NO generating device 100 comprises at least one conductive material coated on at least one substrate. The at least one conductive material may be coated on the at least one substrate using any suitable plating method, such as electroplating, physical Vapor Deposition (PVD), chemical Vapor Deposition (CVD), or Plasma Enhanced Chemical Vapor Deposition (PECVD).

The electrode (such as the first electrode 116) of the NO generating device 100 may have any shape, structure and/or size. In some embodiments, the first electrode 116 provides a surface on and/or near which NO is electrochemically generated. For example, the shape of the first electrode 116 may be in the form of a plate, sheet, mesh, or rod. The surface of the first electrode 116 may have a surface area. This surface area may be positively correlated to the rate of NO generation at the surface. The first electrode 116 may have a structure that allows for a larger surface area, such as a porous structure.

Fig. 3A is a schematic diagram of a first electrode 116 and a second electrode 118 of the NO generating device 100 according to some embodiments of the present disclosure. First electrode 116 and second electrode 118 may be placed in reaction chamber 102 using suitable means such that the surfaces of the first electrode and second electrode are disposed in reaction medium 112. For example, as shown in FIG. 3A, a frame 126 may be used to place the first electrode 116 and the second electrode 118 in the reaction chamber 102. The frame 126 may have a top side that is connected to the first side 104 of the reaction chamber 102. The first electrode 116 and the second electrode 118 may be attached to the frame 126 in any suitable manner, such as by using screws, snaps, wires, clip fasteners, or any other suitable fastening means.

In some embodiments, as shown in fig. 3A, the first electrode 116 and the second electrode 118 comprise two rectangular plates having one or more surfaces 128. The first electrode 116 and the second electrode 118 may have the same size or similar sizes. In some embodiments, the first electrode 116 and/or the second electrode 118 have a length from about 3cm to about 15 cm. In some embodiments, the first electrode 116 and/or the second electrode 118 have a width from about 2cm to about 10cm. The first electrode 116 and the second electrode 118 may be disposed at any suitable distance apart, such as about 0.2cm to about 10cm apart. The first electrode 116 and the second electrode 118 may be disposed such that at least a portion of the surface 128 of the first electrode 116 extends along at least a portion of the surface 128 of the second electrode 118, such as parallel to at least a portion of the surface of the second electrode.

In some embodiments, as shown in fig. 1-2, the first electrode 116 and the second electrode 118 are vertically positioned. For example, the first electrode 116 and the second electrode may be disposed perpendicular to the second side 106 of the reaction chamber 102. In some embodiments, each electrode includes a top edge 130 and a bottom edge 132. The top edge 130 may extend along the first side 104 of the reaction chamber 102, such as parallel to the first side of the reaction chamber. The bottom edge 132 may extend along a second side of the reaction chamber 102, such as parallel to the second side of the reaction chamber.

Wires may be used to electrically connect the electrodes to the energy source 114. For example, as shown in fig. 3A, the wire 136 is connected at a first end to the energy source 114 (not shown) and at a second end to an electrode, such as the first electrode 116 or the second electrode 118. The wire 136 may be soldered or brazed to the electrodes (e.g., the first electrode 116 and the second electrode 118). The wire 136 may be made of one or more conductive materials (such as copper, aluminum, steel, or silver) and may be treated for corrosion protection purposes. In some embodiments, the wires 136 are secured to the frame 126.

In some embodiments, the voltage applied to an electrode (such as first electrode 116) is a DC voltage. In some embodiments, the voltage applied to the electrode (e.g., the first electrode 116) ranges from about 1.0V to about 5.0V, such as from about 1.0V to about 2.0V, from about 2.0V to about 3.0V, from about 3.0V to about 4.0V, from about 4.0V to about 5.0V, or a combination thereof.

In some embodiments, the energy source 114 is configured to apply an excitation voltage to an electrode (such as the first electrode 116). In some embodiments, the excitation voltage is about 2 to about 8 times, such as about 2, about 3, about 4, about 5, about 6, about 7, or about 8 times the predetermined voltage.

In some embodiments, the current applied to an electrode (such as first electrode 116) is a DC current. In some embodiments, the current applied to the electrode (e.g., the first electrode 116) ranges from about 0mA to about 600mA, such as from about 0mA to about 10mA, from about 10mA to about 50mA, from about 50mA to about 100mA, from about 100mA to about 200mA, from about 200mA to about 300mA, from about 300mA to about 400mA, from about 400mA to about 500mA, from about 500mA to about 600mA, or a combination thereof.

In some embodiments, the energy source 114 is configured to apply an excitation current to the first electrode 116. In some embodiments, the excitation current is about 2 to about 8 times, such as about 2, about 3, about 4, about 5, about 6, about 7, or about 8 times the predetermined current.

Those skilled in the art will recognize that the excitation voltage or excitation current need not be an integer multiple of the predetermined voltage or predetermined current. Any number within this range may satisfy the objects disclosed in this disclosure.

The polarity of the voltage or current may be switched, either manually or by software and/or hardware control, to exchange the polarity of the first electrode 116 and the second electrode 118. In some embodiments, the polarity of the first electrode 116 and the second electrode 118 is periodically switched. For example, the polarity of the first and second electrodes 116, 118 may be switched about every 10 minutes to about every 10 hours, such as about every 5 minutes to about every 10 minutes, about every 10 minutes to about every 30 minutes, about every 30 minutes to about every 1 hour, about every 1 hour to about every 2 hours, about every 2 hours to about every 3 hours, about every 3 hours to about every 4 hours, about every 4 hours to about every 5 hours, about every 5 hours to about every 6 hours, about every 6 hours to about every 7 hours, about every 7 hours to about every 8 hours, about every 8 hours to about every 9 hours, about every 9 hours to about every 10 hours, or a combination thereof.

In some embodiments, reaction medium 112 includes at least one buffer or buffer component to regulate or prevent changes in the pH of reaction medium 112. For example, the at least one buffer or buffer component may include one or more organic or inorganic buffers or buffer components selected from the group consisting of sodium hydroxide (NaOH), 4- (2-hydroxyethyl) -1-piperazine ethane sulfonic acid (HEPES), 3- (N-morpholino) propane sulfonic acid (MOPS), citric acid, sodium citrate, tris (hydroxymethyl) aminomethane (Tris), phosphate Buffered Saline (PBS), boric acid, borax, and boric acid-borax buffers. Some other examples of buffers or buffer components that may be used in reaction medium 112 may be found in PCT/US 2018/027081.

The at least one buffer or buffer component in reaction medium 112 can have any suitable concentration. For example, the concentration of the at least one buffer or buffer component in reaction medium 112 can range from about 0.01mol/L to about 0.5mol/L, from about 0.5mol/L to about 1.0mol/L, from about 1.0mol/L to about 1.5mol/L, from about 1.5mol/L to about 2.0mol/L, from about 2.0mol/L to about 2.5mol/L, from about 2.5mol/L to about 3.0mol/L, or a combination thereof.

The nitrite ion source in reaction medium 112 may comprise one or more nitrites. The nitrite may be an organic nitrite or an inorganic nitrite. Examples of the organic nitrite include organic ammonium nitrite salts such as tetramethylammonium nitrite and tetraethylammonium nitrite. Examples of inorganic nitrites include metal nitrites such as nitrites of lithium, sodium, potassium, rubidium, calcium, magnesium, aluminum, and iron. Some other examples of nitrite ion sources can be found in PCT/US 2018/027081. The concentration of the one or more nitrites in reaction medium 112 can range from about 0.01 to about 0.5, from about 0.5 to about 1.0, from about 1.0 to about 1.5, from about 1.5 to about 2.0, from about 2.0 to about 2.5, from about 2.5 to about 3.0, from about 3.0 to about 3.5, from about 3.5 to about 4.0, from about 4.5 to about 5.0, or a combination thereof.

When the catalyst is dissolved in reaction medium 112, the concentration of the catalyst in reaction medium 112 may range from about 1mmol/L to about 5mmol/L, from about 1mmol/L to about 10mmol/L, from about 1mmol/L to about 15mmol/L, from about 5mmol/L to about 10mmol/L, from about 5mmol/L to about 15mmol/L, or from about 10mmol/L to about 15mmol/L.

Reaction medium 112 may include one or more other components. For example, reaction medium 112 may include one or more additives, such as ethylenediamine tetraacetic acid (EDTA), which may promote one or more electrochemical reactions for the generation of NO.

Embodiments of NO generation device 100 may include one or more features described below to improve the performance of NO generation device 100, such as increasing the reaction rate and/or faraday efficiency of NO generation device 100, increasing the concentration of NO in the product gas, or increasing the amount or concentration of NO generated using a given amount of reaction medium 112. For example, the faraday efficiency of the NO generating device 100 may be in the range of about 70% to about 80% or higher.

Temperature control of the reaction medium

In some embodiments, reaction medium 112 is maintained at or near the reaction temperature or within a temperature range. The electrochemical reaction in the reaction chamber 102 may have a highest, desired or optimized reaction rate and/or faraday efficiency at or near the reaction temperature or within a temperature range. The reaction temperature or temperature range may be determined based on one or more conditions, such as the buffer and/or catalyst components and the concentration in reaction medium 112. In some embodiments, the reaction temperature or temperature range may range from about 5 ℃ to about 10 ℃, from about 10 ℃ to about 15 ℃, from about 15 ℃ to about 20 ℃, from about 20 ℃ to about 25 ℃, from about 25 ℃ to about 30 ℃, from about 20 ℃ to about 30 ℃, from about 30 ℃ to about 35 ℃, from about 35 ℃ to about 40 ℃, from about 40 ℃ to about 45 ℃, or a combination thereof.

In some embodiments, NO generation apparatus 100 includes a temperature maintenance device 138 to control the temperature of reaction medium 112. For example, as shown in FIGS. 1-2, the temperature maintenance device 138 may be disposed adjacent to the reaction chamber 102, such as below, beside, or about the reaction chamber 102. In some embodiments, the temperature maintenance device 138 includes one or more temperature control devices, such as a temperature controlled water bath, a temperature controlled oil bath, an air agitation device (e.g., a fan), a heat radiator, a thermoelectric heating and/or cooling device (e.g., a p-n junction device).

In some embodiments, NO generation apparatus 100 includes a temperature sensor 140 disposed in reaction medium 112 and in communication with temperature maintenance device 138. Temperature maintenance device 138 may monitor the temperature of reaction medium 112 based on signals from temperature sensor 140. Temperature maintenance device 138 may be responsive to the signal to heat or cool reaction medium 112. In some embodiments, the voltage or current applied to an electrode (such as first electrode 116) may be adjusted by energy source 114 based on a signal from temperature sensor 140. For example, the control loop of the energy source 114 may be in communication with the temperature sensor 140 and may adjust the magnitude and/or polarity of the voltage or current applied to the first electrode 116.

Delivery of NO from reaction medium

Some or all of the NO generated in reaction medium 112 may be transported from reaction medium 112. For example, NO generated in reaction medium 112 may be transported, such as by sweeping, purging, and/or entraining it from reaction medium 112 to gas region 110 using carrier gas 122.

In some embodiments, as shown in fig. 2, the carrier gas 122 is used to sweep the surface 128 of an electrode (such as the first electrode 116). Sweeping the surface of the electrode may increase the faraday efficiency and/or reaction rate of the electrochemical reaction at and/or near the electrode surface and/or may increase the NO concentration of the product gas. For example, in some cases, one or more metal ions of the catalyst in reaction medium 112, such as M (monovalent) ions generated by electrochemical reaction 2, may precipitate into an insoluble form. For example, the metal ion of the catalyst may be Cu ²⁺ . In some cases, cu ²⁺ Can be precipitated from the following reaction:

Cu ²⁺ +2OH ^- →Cu(OH) ₂ ↓→CuO+H ₂ O

precipitation of the metal ions of the catalyst in reaction medium 112 may reduce the concentration of the catalyst in reaction medium 112 and may reduce the rate of the electrochemical reaction for generating NO. Precipitation of metal ions can result in insoluble forms of the metal ions, such as Cu (OH) ₂ To deposit on the surface of the electrode. This may reduce the surface area for generating NO and may also reduce the lifetime of the electrode. Sweeping the surface of the electrode may increase movement of species (such as metal ions) at and/or near the electrode surface. This may reduce or inhibit deposition of metal ions on the surface and may therefore increase the NO generation rate and/or the NO concentration of the product gas.

Carrier gas 122 may be introduced into reaction medium 112 by one or more flow control devices. For example, as shown in fig. 2, carrier gas source 200 may include a flow control device 204 that may measure and control the mass or volumetric flow rate of carrier gas stream 122 introduced into reaction medium 112. A valve 206 may be provided downstream of the flow control device 204 to protect the flow control device 204. For example, valve 206 may be a one-way valve configured to prevent backflow of reaction medium 112 from inlet circuit 120 to flow control device 204. An embodiment of the supply of the carrier gas 122 from the carrier gas source 200 to the NO generating device 100 will be further described below.

In some embodiments, carrier gas 122 is introduced into reaction medium 112 in the form of bubbles configured to propagate along a bubble path. The bubble path may extend along a surface of the electrode, such as surface 128 of first electrode 116, to sweep the surface. As the carrier gas bubbles rise to the surface of reaction medium 112, the carrier gas bubbles may entrain, sweep, and/or purge NO generated near and/or at surface 128 of first electrode 116. The carrier gas bubbles may mix or disrupt the reaction medium 112 near the surface 128 of the first electrode 116 and the carrier gas bubbles may increase movement of substances (such as metal ions) near the surface. The carrier gas bubbles may purge NO dissolved in reaction medium 112 from reaction medium 112 to gas region 110.

In some embodiments, the NO generating device 100 includes one or more spargers to generate bubbles from the carrier gas 122. As used herein, a sparger may include a device or system configured to emit gas bubbles into a liquid. In some cases, the sprinkler may be referred to as a bubbler. One or more spargers may be positioned at any suitable location in reaction medium 112 to sparge bubbles of carrier gas 122 to transport (e.g., sweep, purge, and/or entrain) NO out of reaction medium 112. For example, one or more spargers can be disposed over or near the second side 106 of the reaction chamber 102.

In some embodiments, as shown in fig. 2, NO generating device 100 includes a first sparger 134 disposed in reaction medium 112 adjacent to first electrode 116. In some embodiments, as shown in fig. 2, the NO generating device 100 includes a second sprayer 134 disposed adjacent to the second electrode 118. In some embodiments, the sparger 134 is configured to receive the carrier gas 122 and the sparger emits bubbles of the carrier gas to sweep across one or more surfaces 128 of the first electrode 116 or the second electrode 118. Fig. 3B is a perspective view of a sprinkler 134 according to some embodiments of the present disclosure. As shown in fig. 3B, the sprinkler 134 may have an elongated shape, such as an elongated cylindrical shape.

In some embodiments, as shown in fig. 3A, the sparger 134 can be disposed along the first electrode 116 or the second electrode 118 such that bubbles emanating from the sparger 134 can rise and propagate along one or more surfaces 128 of the first electrode 116 or the second electrode 118. For example, as shown in fig. 2 and 3A, a sparger 134 can be disposed between the bottom edge 132 of the first electrode 116 or the second electrode 118 and the second side 106 of the reaction chamber 102. Bubbles emanating from the sparger 134 may propagate along bubble paths extending from the bottom edge 132 through the surface 128 to the top edge 130 of the first electrode 116 or the second electrode 118. In some embodiments, the sparger 134 may extend along the length of the bottom edge 132 such that the bubbles may sweep across the entire surface 128 of the first electrode 116.

In some embodiments, the distance between the sprayer 134 and the first electrode 116 or the second electrode 118 may be selected to increase coverage and/or efficiency of the sweep of one or more surfaces of the electrodes. The sprayer 134 may be disposed at a distance from the electrode that is, for example, less than about 1cm, less than about 5mm, less than about 2mm, less than about 1mm, or less than about 0.5mm.

The sparger 134 can have any suitable structure to receive gas and emit bubbles of gas. In some embodiments, the sparger 134 includes a porous structure 141 that provides a plurality of holes for emitting bubbles. For example, as shown in fig. 3B, the sprinkler 134 can include an interior cavity 142 surrounded by a porous structure 141. The gas may flow through the lumen 142 and foam through the pores in the porous structure 141. The lumen 142 may have a tubular shape extending from a first opening to a second opening. The interior cavity 142 may or may not extend along the centerline of the sprinkler 134. The lumen 142 may have a diameter selected based on one or more conditions, such as the flow rate of the received gas and the desired density and/or size of the bubbles. For example, the lumen 142 may have a diameter ranging from about 1mm to about 9mm, such as from about 1mm to about 2mm, from about 2mm to about 3mm, from about 3mm to about 4mm, from about 4mm to about 5mm, from about 5mm to about 6mm, from about 6mm to about 7mm, from about 7mm to about 8mm, from about 8mm to about 9mm, or a combination thereof.

In some embodiments, as shown in fig. 2 and 3A, the outlet 144 of the inlet circuit 120 is fluidly connected to the sprinkler 134 (e.g., the interior cavity 142 of the sprinkler 134). Carrier gas 122 may flow from carrier gas source 200 through inlet circuit 120 to sparger 134 via outlet 144. In some embodiments, the sprinkler 134 is attached to the sprinkler seat 148. In some embodiments, the sprinkler seat 148 is attached to the frame 126. The sprinkler seat 148 may allow the sprinkler 134 to be positioned in a desired location.

In some embodiments, the sprinkler seat 148 may include one or more structures for directing the flow of air bubbles. For example, the sprinkler seat 148 may include a housing having one or more openings configured to direct air bubbles emanating from the sprinkler 134 to one or more surfaces 128 of the electrode. For example, as shown in fig. 3A, the sprinkler seat 148 may include openings at the top and/or upper portions of the sprinkler 134 such that air bubbles may emanate from the upper portion of the sprinkler 134 and propagate along the surface 128 of the first electrode 116. The sprinkler seat 148 may include one or more blocking or sealing devices to prevent one or more portions of the sprinkler 134 from emitting gas or bubbles. For example, the sprinkler seat 148 can have a portion configured to prevent gas from directly exiting the interior cavity 142 without passing through the porous structure 141. For example, the sprinkler seat 148 can have a portion that blocks or seals a first end of the inner cavity 142 opposite a second end connected to the outlet 144.

In some embodiments, the sprinkler 134 includes at least one porous material that provides the porous structure 141. The density and/or size of the bubbles may depend on one or more conditions, such as gas pressure, flow rate of the gas, and density and/or size of the pores of the at least one porous material. Smaller holes may allow sparger 134 to generate smaller bubbles with higher density for a given gas flow rate. The at least one porous material may comprise a metallic material, such as stainless steel. The at least one porous material may comprise a non-metallic material. The nonmetallic material may be a polymeric material such as Polyethylene (PE), polycarbonate (PC), polyvinylidene fluoride (PVDF), ceramic, quartz, or silicon carbide.

The size of the pores of the at least one porous material of the sparger 134 can be selected based on the desired density, size, and/or flow rate of the bubbles. For example, the size of the pores may range from about 0.1 μm to about 0.5 μm, from about 0.1 μm to about 0.2 μm, from about 0.2 μm to about 0.5 μm, from about 0.5 μm to about 1 μm, from about 1.0 μm to about 10 μm, from about 10 μm to about 20 μm, from about 20 μm to about 50 μm, from about 50 μm to about 100 μm, from about 100 μm to about 150 μm, from about 150 μm to about 200 μm, from about 200 μm to about 300 μm, from about 300 μm to about 400 μm, from about 400 μm to about 500 μm, from about 500 μm to about 600 μm, from about 600 μm to about 700 μm, from about 700 μm to about 800 μm, from about 800 μm to about 900 μm, from about 900 μm, or a combination thereof.

The porous material of the sparger 134 can have a thickness through which the gas stream can pass to create bubbles. The thickness of the porous material may be measured from the inner surface to the outer surface of the porous material. Increasing the thickness of the porous material can increase gas flow resistance and reduce bubbling efficiency. Reducing the thickness of the porous material may reduce the density and/or velocity of the bubbles. The thickness of the porous material may be selected to obtain any suitable density and/or size of bubbles for sweeping the electrode surface. For example, the thickness of the porous material may range from about 0.5mm to about 1mm, from about 1mm to about 2mm, from about 2mm to about 3mm, from about 3mm to about 4mm, from about 4mm to about 5mm, from about 5mm to about 6mm, from about 6mm to about 7mm, from about 7mm to about 8mm, from about 8mm to about 9mm, from about 9mm to about 10mm, or a combination thereof.

Carrier gas generation

In some embodiments, the carrier gas 122 is generated or supplied by a carrier gas source 200. Carrier gas 122 may include any suitable gas such as air, nitrogen, helium, argon, and oxygen. In some embodiments, the carrier gas 122 comprises nitrogen. In some embodiments, the concentration of nitrogen in the carrier gas 122 is about 99.0% by volume or greater than 99.0% by volume. For example, the concentration of nitrogen in the carrier gas 122 may be about or greater than 99.10%, 99.20%, 99.30%, 99.40%, 99.50%, 99.60%, 99.70%, 99.80%, 99.90%, 99.95%, 99.98%, or 99.99% by volume. The carrier gas 122 may contain oxygen. For example, the concentration of oxygen in the carrier gas 122 may be less than about 1%, 0.5%, or 0.1%.

In some embodiments, as shown in fig. 1, the carrier gas source 200 includes a nitrogen generation device 202 configured to generate the carrier gas 122 from compressed air. In some embodiments, compressed air is supplied to the carrier gas source 200 from an air compressor system or reservoir. In some embodiments, the compressed gas is filtered prior to being supplied to the carrier gas source 200. For example, the carrier gas source 200 may include a filtration device disposed upstream of and configured to be in fluid communication with the nitrogen generation device 202. The filter device may comprise one or more filters, such as dust filters and moisture filters. In some embodiments, the carrier gas source 200 includes a pressure sensor and a pressure controller, such as a pressure regulator or a pressure control valve. The pressure controller may regulate the pressure and/or flow of compressed air into the nitrogen generation apparatus 202 based on a response or signal from the pressure sensor.

The nitrogen generation apparatus 202 may include one or more suitable devices for generating nitrogen from compressed air. In some embodiments, nitrogen generation apparatus 202 includes at least one Carbon Molecular Sieve (CMS). The carbon molecular sieve may have a pore size distribution that allows for the separation of nitrogen from air. In some embodiments, nitrogen generation apparatus 202 includes at least one nitrogen separation membrane. The nitrogen separation membrane may separate nitrogen from air based on the permeation rates of nitrogen and oxygen through the membrane wall. The nitrogen separation membrane may have any suitable configuration. In some embodiments, the nitrogen separation membrane comprises at least one bundle of selectively permeable hollow fibers.

The nitrogen separation membrane may include one or more materials selected from the group consisting of poly (4-methyl-1-pentene), brominated polycarbonate, polypropylene, polyimide, and polydimethylsiloxane. In some embodiments, the nitrogen separation membrane has a plurality of pores having an average pore size ranging from about 0.005 μm to about 0.007 μm, from about 0.007 μm to about 0.01 μm, from about 0.01 μm to about 0.013 μm, from about 0.013 μm to about 0.015 μm, from about 0.015 μm to about 0.017 μm, from about 0.017 μm to about 0.019 μm, from about 0.019 μm to about 0.02 μm, or a combination thereof.

As described herein, the description of nitrogen generation apparatus 202 is generally applicable to apparatus that generate other carrier gases (such as helium, argon, and oxygen) and will be apparent to the skilled artisan.

In some embodiments, the nitrogen generation apparatus 202 is disposed upstream of and in fluid communication with the inlet circuit 120. In some embodiments, as shown in fig. 1, the carrier gas source 200 further includes a flow control device 204 disposed downstream of the nitrogen generation apparatus 202 and upstream of the inlet circuit 120. The flow control device 204 may be configured to control the flow of the carrier gas 122 into the NO generating apparatus 100. Increasing the flow of carrier gas 122 may increase the rate of NO generation and/or the concentration of NO in the product gas. For example, increasing the flow of carrier gas 122 may increase the sweep of the surface of first electrode 116 and may increase the rate of transport of generated NO from reaction medium 112. In some embodiments, the flow rate of the product gas of the NO generation apparatus 100 output from the outlet loop 124 is proportional to the flow rate of the carrier gas 122.

Recirculation of product gas relative to reaction chamber

In some embodiments, as shown in fig. 2, the NO generating device 100 includes a gas circulation loop 300. In some embodiments, the gas circulation loop 300 includes a circulation inlet 302 and a circulation outlet 304. In some embodiments, the circulation inlet 302 is in fluid communication with the gas region 110 of the reaction chamber 102. For example, the circulation inlet 302 may include an opening disposed inside or on a wall of the gas region 110. In some embodiments, the circulation outlet 304 is in fluid communication with the liquid region 108 of the reaction chamber 102. For example, the circulation outlet 304 may be in fluid communication with the inlet circuit 120. For example, the circulation outlet 304 may include an opening disposed inside or on a wall of the liquid region 108.

In some embodiments, the product gas in the gas region 110 is recycled from the recycle inlet 302 to the recycle outlet 304 relative to the reaction chamber 102. For example, recycled product gas 303 may flow from recycle inlet 302 to recycle outlet 304. In some embodiments, the gas circulation loop 300 includes a gas pump 306 configured to generate a recycled product gas stream 303. A gas pump 306 may be disposed downstream of the circulation inlet 302 and upstream of the circulation outlet 304.

In some embodiments, as shown in fig. 2, the gas circulation loop 300 is in fluid communication with the outlet loop 124 of the NO generating device 100. For example, the circulation inlet 302 of the gas circulation loop 300 may be in fluid communication with the outlet loop 124. The gas circulation loop 300 and the outlet loop 124 may have a common inlet, such as circulation inlet 302. The gas circulation loop 300 and the outlet loop 124 may have a common fluid path. In some embodiments, the gas circulation loop 300 includes a first filtration device 508 disposed downstream of the circulation inlet 302. The common fluid path may extend from the common inlet to the first filter arrangement 508.

In some embodiments, the first filter device 508 is disposed upstream of the gas pump 306. The filtration device 508 can reduce or remove liquid and/or solid materials in the recycled product gas 303. In some embodiments, the gas circulation loop 300 includes a second filtration device 307. The second filtering means 307 may comprise a capsule filter or a membrane filter. The second filtering device 307 may remove one or more impurities (such as liquid and solid materials) in the recycled product gas 303, thereby shielding the gas pump 306.

The recycled product gas 303 can be introduced to the surface of an electrode to sweep across the surface of the electrode. In some embodiments, the circulation outlet 304 is in fluid communication with the sprinkler 134. For example, the circulation outlet 304 may be fluidly connected with the interior cavity 142 of the sprinkler 134. A gas pump 306 may be disposed downstream of the circulation inlet 302 and upstream of the sparger 134, and recycled product gas 303 may flow from the circulation inlet 302 to the inner cavity 142 of the sparger 134.

In some embodiments, as shown in fig. 2, recycled product gas 303 is combined with carrier gas 122 into gas stream 146. For example, the gas circulation loop 300 may include a three-way connector 308. A three-way connector 308 may be fluidly connected to the recycle outlet 304 and configured to receive the recycled product gas 303. The three-way connector 308 may be fluidly connected to the carrier gas source 200 and/or the inlet circuit 120 and configured to receive the carrier gas 122. The three-way connector 308 may combine the received recycled product gas 303 and the carrier gas 122 into a gas stream 146. The three-way connector 308 may comprise any suitable structure, such as a three-way fitting or a three-way valve. A gas stream 146 may be supplied to the sparger 134 to generate bubbles for sweeping across the electrode surface.

In some embodiments, the gas circulation loop 300 may include a valve 206. The valve 206 may be disposed upstream of the circulation outlet 304. The valve 206 may be disposed downstream of the gas pump 306 and may be disposed downstream of the three-way connector 308. Valve 206 may prevent backflow of gas stream 146 and/or backflow of reaction medium 112 from reaction chamber 102 to gas pump 306. The gas flow 146 may flow through the valve 206 to the circulation outlet 304 and the outlet 144 and be supplied to one or more sprinklers 134. One or more spargers 134 can also emit gas bubbles from gas stream 146 to transport (e.g., sweep, purge, and/or entrain) NO generated in reaction medium 112 to gas region 110. For example, in some embodiments, the sparger 134 emits bubbles from the gas stream 146 to sweep across the surface of an electrode (such as the first electrode 116).

The product gas in the gas region 110 may include the carrier gas 122 and the generated NO. In some embodiments, recycling the product gas in the gas region 110 allows for recycling the carrier gas 122 in the product gas to the surface of the electrode. Recirculating the carrier gas may reduce the amount of carrier gas required to support NO generation, e.g., for sweeping the first electrode 116 and/or transporting the generated NO. Recycling the product gas may allow NO to accumulate in the product gas in the gas region 110 of the reaction chamber 102, allowing for a higher concentration of NO in the product gas in the gas region 110. This may allow for a higher and/or more stable concentration of NO in the product gas transported from the gas region 110 of the NO generating device 100.

Fig. 4A is a graphical representation of the concentration of NO in the product gas versus the current applied to the first electrode 116 in accordance with some embodiments of the present disclosure. In this example, the NO generating device 100 may include a reaction chamber 102 having a gas region and a liquid region, a reaction medium 112 contained in the liquid region, a first electrode 116 and a second electrode 118 disposed in the reaction medium 112, a sparger 134 for sweeping a surface of the first electrode 116, a gas circulation loop 300 for recirculating a product gas, and a sparger 134 for sweeping the first electrode 116. The electrodes may each be made of stainless steel and may each comprise a plate having a surface area of about 5cm by about 6 cm. Reaction medium 112 may include about 1.0mol/L NaNO ₂ CuSO of about 7mmol/L ₄ Me of about 7mmol/L ₃ TACN and approximately 0.5mol/L HEPES buffer. The HEPES buffer may be titrated with a suitable alkaline solution (e.g., naOH solution) such that the reaction medium 112 may have a pH of about 6 to about 8, such as a pH of about 7.2. The sparger 134 can be cylindrical with a length of about 7cm, an inner diameter of about 5mm, an outer diameter of about 10mm, and an average pore size of about 20 μm. Carrier gas 122 having a concentration of about 99.7% N2 by volume may be introduced to sparger 134 at a flow rate of about 300 mL/min. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 3L/min. As shown in fig. 4A, the concentration of NO in the product gas may be increased by increasing the current applied to the first electrode 116 from about 0mA to about 300 mA. In this example, fitting the data to a linear regression model showed that the concentration of NO in the product gas could be increased by about 36.1ppm for every 1mA of applied current, andthe NO generating device 100 may have a faraday efficiency of 70.7%. Reducing the sweep of the first electrode 116 may reduce the increase in NO concentration caused by the applied current per unit and may reduce faraday efficiency.

Fig. 4B is a graphical representation of the concentration of NO in the product gas generated by the NO generation apparatus 100 over time, according to some embodiments of the present disclosure. In this example, the NO generating device 100 may have the same reaction conditions as described above with reference to the example of fig. 4A, except that after an initial current of about 300mA is applied in a ramp period of about 2 minutes, a current of 100mA may be applied to the first electrode 116 for about 60 hours. After the ramp period, the concentration of NO in the product gas of the NO generation apparatus 100 increases to about 3600ppm and remains at a steady state concentration of 3600ppm or about 3600ppm for about 60 hours. The production of such amounts of NO typically requires about 4 to 5 cylinders to store about 8L of compressed NO having a NO concentration of about 800ppm at a pressure of about 13.8 MPa. The use of sparger 134 to sweep the surface of first electrode 116 and the recirculation of the product gas through gas circulation loop 300 allows NO to be generated at a steady concentration over a longer period of time. The amount of NO that can be generated by the NO generating device 100, such as a product gas having a NO concentration of about 3600ppm over about 60 hours.

Separation of NO from the reaction Medium

The reaction medium 112 of the NO generating device 100 may be reused to generate NO before being treated, replaced or replenished. For example, reaction medium 112 of NO-generating device 100 may be used to generate NO over multiple operating cycles in one phase or in multiple phases. Some of the generated NO may dissolve in reaction medium 112 after a period or phase of operation. The NO dissolved in reaction medium 112 can reduce the concentration and/or amount of NO that can be generated by the reuse of reaction medium 112 and can increase the latency between stages or operating cycles.

For example, NO dissolved in reaction medium 112 may interact with a metal-ligand complex catalyst, such as Cu (II) -1,4, 7-trimethyl-1, 4, 7-triazacyclononane (Cu (Me) ₃ TACN)). For example, during the waiting time between the two phases, NO dissolved in reaction medium 112 may bind to Cu (Me ₃ TACN) on the central copper ion. This may reduce the concentration of metal-ligand complex in reaction medium 112 for catalyzing the electrochemical reaction for the generation of NO in the next stage, and may reduce the reaction rate of the next stage and/or the concentration of NO in the product gas. In some cases, the concentration of NO in the product gas of one stage may be lower than the concentration of NO in the product gas of the previous stage, such as from about 10% to about 30% lower.

In some embodiments, one or more spargers 134 disposed within reaction medium 112 can generate gas bubbles to purge dissolved NO from reaction medium 112 to gas region 110, thereby reducing dissolved NO in reaction medium 112. In some embodiments, sweeping the surface of the electrode may reduce NO dissolved in reaction medium 112. For example, the sparger 134 can generate gas bubbles to propagate along and sweep across the surface 128 of the first electrode 116. The gas bubbles may entrain and/or sweep NO generated at and/or near the surface of first electrode 116 from reaction medium 112, which may reduce or prevent dissolution of the generated NO in reaction medium 112.

In some embodiments, as shown in fig. 1 and 2, NO-generating device 100 includes a liquid-gas separation circuit 400 to reduce or remove dissolved NO in reaction medium 112. The liquid-gas separation circuit 400 is configured to circulate a fluid stream (such as a liquid stream or a gas stream) relative to the reaction chamber 102. The liquid-gas separation circuit 400 may be used before, during, and/or after the reaction medium 112 is reused to generate NO.

In some embodiments, as shown in fig. 2, the liquid-gas separation circuit 400 includes a first port 402 and a second port 410. In some embodiments, the first port 402 is in fluid communication with the liquid region 108. The first port 402 may include an opening in the liquid region 108 of the reaction chamber 102 (e.g., below the level of the reaction medium 112). In some embodiments, the second port 410 is in fluid communication with the gas region 110. The second port 410 may have an opening in the gas region 110 of the reaction chamber 102 (e.g., above the level of the reaction medium 112). In some embodiments, the liquid-gas separation circuit 400 is configured to circulate the reaction medium stream 112 relative to the reaction chamber 102 from the first port 402 to the second port 410. In some embodiments, the liquid-gas separation circuit 400 is configured to circulate a product gas stream relative to the reaction chamber 102 from the second port 410 to the first port 402.

In some embodiments, the liquid-gas separation circuit 400 includes a pump 406. In some embodiments, pump 406 is a liquid-gas dual-purpose pump. In some embodiments, pump 406 is a reversible pump. The pump 406 may generate a fluid flow from the first port 402 to the second port 410 or from the second port 410 to the first port 402. In some embodiments, the fluid stream is a liquid stream. For example, pump 406 may generate reaction medium stream 112 from first port 402 to second port 410. In some embodiments, the fluid stream is a gas stream. For example, the pump 406 may generate a product gas stream from the second port 410 to the first port 402.

Pump 406 may generate the fluid flow at any suitable flow rate. For example, the pump 406 may generate a fluid flow (such as a reaction medium flow) at a flow rate ranging from about 0.25L/min to about 10L/min, such as from about 0.5L/min to about 1.0L/min, from about 1.0L/min to about 1.5L/min, from about 1.5L/min to about 2.0L/min, from about 2.0L/min to about 2.5L/min, from about 2.5L/min to about 3.0L/min, from about 3.0L/min to about 3.5L/min, from about 3.5L/min to about 4.0L/min, from about 4.0L/min to about 4.5L/min, from about 4.5L/min to about 5.0L/min, from about 5.0L/min to about 5.5L/min, from about 5.5L/min to about 6.7.0L/min to about 6.5L/min, from about 7.0L/min to about 8.5L/min, from about 7.5L/min to about 8.5L/min, from about 6.5L/min, from about 7.5L/min to about 8.5L/min.

In some embodiments, as shown in fig. 1 and 2, the liquid-gas separation circuit 400 includes a liquid-gas separation device 408. In some embodiments, the liquid-gas separation device 408 is disposed between the first port 402 and the second port 410. The liquid-gas separation device 408 may be disposed downstream or upstream of the pump 406. In some embodiments, the liquid-gas separation device 408 includes at least one first chamber 414 and at least one second chamber 416. The first chamber 414 and/or the second chamber 416 may have any suitable shape and size. For example, the first chamber 414 and/or the second chamber 416 may have a tubular structure. The first chamber 414 may be received in the second chamber 416 and vice versa. In some embodiments, the liquid-gas separation device 408 includes a housing or shell configured to enclose a first chamber 414 and a second chamber 416.

In some embodiments, the first chamber 414 and the second chamber 416 are separated by a separation membrane. The separation membrane may comprise a NO permeable material. For example, the separation membrane may include a material such as Polydimethylsiloxane (PDMS), silicone, or polypropylene. NO may diffuse from the liquid in the first chamber 414 through the separation membrane into the gas in the second chamber 416. The separation membrane may have any suitable configuration. For example, a plurality of hollow fibers having walls formed of separation membranes.

The separation membrane may be selected to have any suitable area that allows for the reduction or removal of dissolved NO in reaction medium 112 over a certain period and/or a certain amount of circulation. In some embodiments, the separation membrane of the liquid-gas separation device 408 has a surface area ranging from about 500cm ² To about 50000cm ² Such as from about 500cm ² To about 1000cm ² From about 1000cm ² To about 5000cm ² From about 5000cm ² To about 10000cm ² From about 10000cm ² To about 15000cm ² From about 15000cm ² To about 20000cm ² From about 20000cm ² To about 25000cm ² From about 25000cm ² To about 30000cm ² From about 30000cm ² To about 35000cm ² From about 3 5000cm ² To about 40000cm ² From about 40000cm ² To about 45000cm ² From about 45000cm ² To about 50000cm ² Or a combination thereof.

In some embodiments, the first chamber 414 includes an inlet 418 and an outlet 420. Pump 406 may drive reaction medium 112 from inlet 418 through first chamber 414 to outlet 420. As reaction medium 112 flows through first chamber 414, NO dissolved in reaction medium 112 may diffuse through the separation membrane into second chamber 416. In some embodiments, the second chamber 416 includes an inlet 422 and an outlet 426. The sweep gas may flow from the inlet 422 through the second chamber 416 to the outlet 426. The sweep gas may carry the NO diffused into the second chamber 416 out of the outlet 426 as a mixed gas. The mixed gas may be delivered to an exhaust treatment device 700, as described further below.

The sweep gas may comprise any suitable gas, such as air, oxygen, and nitrogen, or combinations thereof. The sweep gas may be supplied to the inlet 422 from a gas source, such as the carrier gas source 200. In some embodiments, the carrier gas 122 is used as a sweep gas. For example, a fluid controller 424 may be used to control the flow of the carrier gas 122 from the carrier gas source 200 to the inlet 422. The fluid controller 424 may include a pressure controller, such as a pressure control valve or a pressure regulator controller.

In some embodiments, as shown in fig. 2, the NO generating device 100 comprises a filtering means 412. In some embodiments, the filtration device 412 is disposed upstream of the liquid-gas separation device 408. Filtration device 412 may include one or more filters configured to filter one or more impurities (such as solid matter) from reaction medium 112. Filtration device 412 may protect the separation membrane of liquid-gas separation device 112 from contaminants in reaction medium 112 as reaction medium 112 flows through liquid-gas separation device 408.

In some embodiments, the liquid-gas separation circuit 400 has an operational mode and a cleaning mode. In the operational mode, liquid-gas separation circuit 400 may reduce or remove dissolved NO in reaction medium 112 by circulating reaction medium 112 from first port 402 to second port 410 through liquid-gas separation device 408. In the cleaning mode, gas in the gas region 110 of the reaction chamber 102 may be circulated from the second port 410 to the first port 402 through the liquid-gas separation device 408. Circulating the gas through the liquid-gas separation device 408 may transport the residual reaction medium 112 in the liquid-gas separation device 408 back to the reaction chamber 102 after the mode of operation. For example, the pump 406 may generate a fluid flow (such as a gas flow in the gas region 110) at a flow rate ranging from about 0.25L/min to about 5L/min, such as from about 0.25L/min to about 0.5L/min, from about 0.5L/min to about 1.0L/min, from about 1.0L/min to about 1.5L/min, from about 1.5L/min to about 2.0L/min, from about 2.0L/min to about 2.5L/min, from about 2.5L/min to about 3.0L/min, from about 3.0L/min to about 3.5L/min, from about 3.5L/min to about 4.0L/min, from about 4.0L/min to about 4.5L/min, from about 4.5L/min to about 5.0L/min, or a combination thereof. The cleaning mode may reduce losses of reaction medium 112 and may extend the life of reaction medium 112 and/or NO generating device 100. The cleaning mode may dry the separation membrane and prepare it for the next operation mode.

In some embodiments, as shown in fig. 2, the liquid-gas separation circuit 400 includes a switching valve 404 for switching the liquid-gas separation circuit 400 between the operational mode and the cleaning mode. In some embodiments, the switching valve 404 includes one or more valves configured to control the direction of fluid flow of the liquid-gas separation circuit 400. For example, the switching valve 404 may include a set of normally closed valves, and the switching valve may change the direction of fluid flow in the liquid-gas separation circuit 400 by opening different subsets of valves. In this case, the pump 406 may not necessarily be a reversible pump to operate in the working mode and the cleaning mode.

For example, as shown in FIG. 2, the switching valve 404 may include a set of four valves 404a-404d. In some cases, valve 404a is disposed between first port 402 and pump 406; valve 404b is disposed between first port 402 and fluid outlet 420 of first chamber 414; valve 404c is disposed between second port 410 and pump 406; and valve 404d is disposed between second port 410 and fluid outlet 420 of first chamber 414. For example, in the operational mode, valves 404a and 404d are open and valves 404b and 404c are closed. Reaction medium 112 may flow from first port 402 to second port 410 through valve 404a, pump 406, fluid inlet 418 and fluid outlet 420 of liquid-gas separation device 408, and valve 404d. For example, in the cleaning mode, valves 404a and 404d are closed and valves 404b and 404c are open. The gas in the gas region 110 of the reaction chamber 102 may flow from the second port 410 to the first port 402 through the valve 404c, the pump 406, the fluid inlet 418 and the fluid outlet 420 of the liquid-gas separation device 408, and the valve 404 b.

In some embodiments, the liquid-gas separation circuit 400 includes a solenoid valve (not shown). A solenoid valve may be disposed upstream of the liquid-gas separation device 408. Solenoid valve may prevent reaction medium 112 from entering liquid-gas separation device 408 due to pressure that may build up in reaction medium 112 during electrochemical generation of NO.

Fig. 4C is a graphical representation of the concentration of NO in the product gas generated by NO generation apparatus 100 during multiple phases, according to some embodiments of the present disclosure. In this example, the NO generating device 100 may have the same reaction conditions as described above with reference to the example of fig. 4A, except that after an initial current of about 150mA is applied in a ramp period of about 2 minutes in multiple phases, a current of 50mA may be applied to the first electrode 116. The NO generating device 100 may further comprise a liquid-gas separation circuit 400. After termination of the current applied to first electrode 116 in each stage, liquid-gas separation circuit 400 may be operated in an operational mode and the liquid-gas separation circuit may circulate reaction medium 112 through liquid-gas separation device 408 at a flow rate of about 0.5L/min for about 10 minutes to reduce or remove dissolved NO in a given reaction medium 112. The liquid-gas separation circuit 400 may then be operated in a cleaning mode, and the liquid-gas separation circuit circulates gas in the gas region 110 through the liquid-gas separation device 408 at a flow rate of about 1L/min for about 0.5 minutes. As shown in FIG. 4C, NO generating device 100 using reaction medium 112 may generate a product gas having a NO concentration of about 2000ppm in five consecutive stages.

Some examples of NO systems are provided below. In some examples, NO system 10 may include NO generating device 100 and carrier gas source 200. The NO generating device 100 may comprise a reaction chamber 102 having a gas zone and a liquid zone, a reaction medium 112 contained in the liquid zone, a cathode and an anode arranged in the reaction medium 112, two spargers 134, a gas circulation loop 300, and a liquid-gas separation loop 400. The spargers 134 may be disposed adjacent to the two electrodes, respectively, and configured to emit bubbles to propagate over the surfaces of the electrodes. The carrier gas source 200 may generate the carrier gas 122 from compressed air. The carrier gas source 200 may include a moisture filter and a dust filter to reduce or remove moisture and solid matter from the compressed air. The carrier gas source 200 may further include a nitrogen generation apparatus 202 having a nitrogen separation membrane to separate N2 from the compressed air. The cathode and anode may be electrically connected to a power source. The power supply may apply a current or voltage to the cathode and NO may be generated at or near the surface of the cathode and swept or entrained by the carrier gas 122 to the gas region to generate a product gas. The gas circulation loop 300 may recirculate the product gas from the gas region to the sparger. The recycle gas may be combined with the carrier gas 122 to be introduced into the sparger. Liquid-gas separation circuit 400 may include liquid-gas separation device 408 to separate NO dissolved in the reaction medium after termination of the application of a voltage or current to the cathode upon application of a current or voltage to the cathode. The liquid-gas separation device 408 may include a separation membrane having a surface area. The liquid-gas separation circuit 400 may operate in an operational mode during a first period and may operate in a cleaning mode during a second period that follows the first period.

For example, the cathode and anode may be made of platinum. The reaction medium may include about 0.01mol/L HEPES buffer, about 0.01mol/L sodium nitrite, and about 1mmol/L copper-tris (2-pyridylmethyl) amine (CuTPMA). Suitable alkaline solutions (such as NaOH solution) may be usedThe HEPES buffer is titrated so that the reaction medium can have a pH of about 6 to about 8, such as a pH of about 7.2. An excitation current of about 20mA may be applied to the cathode for about 0.5 minutes before an electric current of about 10mA is applied to the cathode. The nitrogen separation membrane of the nitrogen generating apparatus 202 may be made of poly (4-methyl-1-pentene) and may have an average pore diameter of about 0.01 μm. The nitrogen generation apparatus 202 may generate the carrier gas 122 containing N2 at a concentration of about 99.0% by volume from the compressed air. Carrier gas 122 may be introduced to sparger 134 at a flow rate of about 50 mL/min. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 0.5L/min. After a ramp period of about 10 minutes of applying the current to the cathode, the NO generating device 100 may output a product gas having a NO concentration of about 200 ppm. After terminating the application of current to the cathode, the liquid-gas separation circuit 400 may be operated in the operating mode for about 10 minutes and thereafter may be operated in the cleaning mode for about 1 minute. The separation membrane of the liquid-gas separation device 408 may have a thickness of about 25000cm ² Is a surface area of the substrate.

As another example, the cathode and anode may be made of gold. The reaction medium may include about 1mol/L MOPS buffer, about 1mol/L sodium nitrite, and about 3mmol/L Fe-1,4, 7-triazacyclononane. The MOPS buffer can be titrated with a suitable alkaline solution (e.g., naOH solution) such that the reaction medium can have a pH of about 6 to about 8, such as a pH of about 7.2. An excitation voltage of about 4.2V may be applied to the cathode for about 1 minute before applying a voltage of about 1.4V to the cathode. The nitrogen separation membrane of the nitrogen generating device 202 may be made of brominated polycarbonate and may have an average pore size of about 0.02 μm. The nitrogen generation apparatus 202 may generate the carrier gas 122 containing N2 at a concentration of about 99.6% by volume from compressed air. Carrier gas 122 may be introduced to sparger 134 at a flow rate of about 100 mL/min. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 1L/min. After a ramp period of about 9 minutes of voltage applied to the cathode, the NO generating device 100 may output a product gas having a NO concentration of about 1200 ppm. After termination of the voltage application to the cathode, the liquid-gas separation circuit 400 may be operated in the working mode for about 5 minutes and thereafter may be operated in the cleaning mode for about 0.5 minutes. The separation membrane of the liquid-gas separation device 408 may have a thickness of about 1000cm ² Is a surface area of the substrate.

As another example, the cathode and anode may be made of carbon. The reaction medium may comprise about 1.5mol/L Tris buffer, about 2mol/L potassium nitrite, and about 4mmol/L Ti (Me) ₃ TACN). Tris buffer may be titrated with a suitable alkaline solution (such as NaOH solution) so that the reaction medium may have a pH of about 6 to about 8, such as a pH of about 7.2. An excitation current of about 500mA may be applied to the cathode for about 1.5 minutes before an electric current of about 100mA is applied to the cathode. The nitrogen separation membrane of the nitrogen generating apparatus 202 may be made of polypropylene and may have an average pore size of about 0.012 μm. The nitrogen generation apparatus 202 may generate the carrier gas 122 containing N2 at a concentration of about 99.7% by volume from compressed air. Carrier gas 122 may be introduced to sparger 134 at a flow rate of about 200 mL/min. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 1.5L/min. After a ramp period of about 6 minutes of applying the current to the cathode, the NO generating device 100 may output a product gas having a NO concentration of about 3000 ppm. After terminating the application of current to the cathode, the liquid-gas separation circuit 400 may be operated in the operating mode for about 12 minutes and thereafter may be operated in the cleaning mode for about 0.9 minutes. The separation membrane of the liquid-gas separation device 408 may have a thickness of about 1000cm ² To about 50000cm ² For example about 50000cm ² 。

As another example, the cathode and anode may be made of SiO coated with glassy carbon ₂ Is prepared. The reaction medium may include about 2mol/L MOPS buffer, about 3mol/L sodium nitrite, and about 5mmol/L chromium-tris (2-pyridylmethyl) amine (CrTPMA). The MOPS buffer can be titrated with a suitable alkaline solution (e.g., naOH solution) such that the reaction medium can have a pH of about 6 to about 8, such as a pH of about 7.2. An excitation voltage of about 12V may be applied to the cathode for about 2 minutes before applying a voltage of about 2V to the cathode. Nitrogen generating device 202The nitrogen separation membrane may be made of polyimide and may have an average pore size of about 0.005 μm. The nitrogen generation apparatus 202 may generate the carrier gas 122 containing N2 at a concentration of about 99.99% by volume from compressed air. Carrier gas 122 may be introduced to sparger 134 at a flow rate of about 300 mL/min. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 2L/min. After a ramp period of about 5 minutes of applying a voltage to the cathode, the NO generating device 100 may output a product gas having a NO concentration of about 4200 ppm. After termination of the voltage application to the cathode, the liquid-gas separation circuit 400 may be operated in the operating mode for about 5 minutes and thereafter may be operated in the cleaning mode for about 1.5 minutes. The separation membrane of the liquid-gas separation device 408 may have a thickness of about 1000cm ² To about 5000cm ² For example about 37500cm ² 。

As another example, the cathode and anode may be made of conductive glass coated with stainless steel. The reaction medium may include about 2.5mol/L phosphate buffer, about 4mol/L sodium nitrite, and about 6mmol/L manganese-tris (2-pyridylmethyl) amine (MnTPMA). The phosphate buffer may be titrated with a suitable alkaline solution (such as NaOH solution) so that the reaction medium may have a pH of about 6 to about 8, such as a pH of about 7.2. An excitation current of about 1.4A may be applied to the cathode for about 2.5 minutes before an electric current of about 200mA is applied to the cathode. The nitrogen separation membrane of the nitrogen generating apparatus 202 may be made of Polydimethylsiloxane (PDMS) and may have an average pore size of about 0.008 μm. The nitrogen generation apparatus 202 may generate the carrier gas 122 containing N2 at a concentration of about 99.8% by volume from compressed air. Carrier gas 122 may be introduced to sparger 134 at a flow rate of about 400 mL/min. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 2.5L/min. After a ramp period of about 4.6 minutes of applying the current to the cathode, the NO generating device 100 may output a product gas having a NO concentration of about 6300 ppm. After terminating the application of current to the cathode, the liquid-gas separation circuit 400 may be operated in the operating mode for about 20 minutes and thereafter may be operated in the cleaning mode for about 2 minutes. Liquid-gas separation The separation membrane of device 408 may have a thickness of about 1000cm ² To about 5000cm ² For example about 12500cm ² 。

For another example, the cathode and anode may be made of stainless steel coated with an iridium-ruthenium alloy. The reaction medium may include about 3mol/L boric acid-borax buffer, about 5mol/L potassium nitrite, and about 7mmol/L cobalt- (bis (2-aminoethylethylpropidium) propionic acid. The boric acid-borax buffer may be titrated with a suitable alkaline solution (e.g., naOH solution) such that the reaction medium may have a pH of about 6 to about 8, such as about 7.2. Before applying a voltage of about 3V to the cathode, an excitation voltage of about 24V may be applied to the cathode for about 3 minutes. The nitrogen separation membrane of the nitrogen generation apparatus 202 may be made of brominated polycarbonate and may have an average pore size of about 0.015 μm. The nitrogen generation apparatus 202 may generate a carrier gas 122 containing N2 at a concentration of about 99.9% by volume from compressed air. The carrier gas 122 may be introduced to the sparger 134. The gas circulation loop 300 may recirculate the product gas at a flow rate of about 3L/min, after applying a voltage of about 5V to the cathode for about 3 minutes, the nitrogen separation membrane may be applied to the cathode for about 400 minutes, and may operate in a clean mode at a concentration of about 100 ppm to the cathode for about 100 minutes, at a separation gas concentration of about 408. About 2 m may be terminated, and the separation membrane may operate in a separation mode may have a gas separation mode of about 100.408 m may be completed after applying a voltage of about 5 ppm to the voltage to the cathode ² To about 5000cm ² For example about 5000cm ² 。

Product gas filtration

The system 10 may include one or more filtration systems or devices to reduce or remove one or more impurities in the product gas. In some embodiments, as shown in fig. 1, the system 10 includes a filtration system 500 disposed downstream of the NO generation device 100. For example, the filtration system 500 may be disposed downstream of and in fluid communication with the gas region 110 and/or the outlet circuit 124 of the NO generating device 100. The filtration system 500 may reduce or remove one or more impurities, such as moisture and/or solid substances, in the product gas from the NO generating device 100. As described herein, moisture can include any liquid, such as water vapor, water droplets, solvent vapor, and solvent droplets, in the gas phase or liquid phase that may be present in the product gas.

The filtration system 500 may include one or more filtration devices or filters. In some embodiments, the filtration system 500 includes one or more solid matter filters 502. It is contemplated that solid matter filter 502 can be configured to filter any type of solid matter by, for example, modifying or selecting filter materials and/or pore sizes. In one embodiment, the solid filter 502 may be a salt aerosol filter. In some embodiments, the solid matter filter 502 comprises a membrane filter. The membrane filter may comprise a polymeric material having a porous structure. For example, the polymeric material may include one or more materials selected from Polytetrafluoroethylene (PTEF), polyvinylidene fluoride, polyethersulfone, mixed cellulose esters, polyamide (nylon), nylon 6, and nylon 66. The average pore size of the porous structure may range from about 0.01 μm to about 2 μm, such as from about 0.1 μm to about 0.2 μm, from about 0.2 μm to about 0.4 μm, from about 0.4 μm to about 0.6 μm, from about 0.6 μm to about 0.8 μm, from about 0.8 μm to about 1.0 μm, from about 1.0 μm to about 1.2 μm, from about 1.2 μm to about 1.4 μm, from about 1.4 μm to about 1.6 μm, from about 1.6 μm to about 1.8 μm, from about 1.8 μm to about 2 μm, or a combination thereof.

In one example, the solid matter filter 502 may comprise a component filter made of PTEF having an average pore size of about 1.0 μm. In another example, the solid matter filter 502 may comprise a component filter made of polyvinylidene fluoride having an average pore size of about 0.1 μm. In another example, the solid matter filter 502 may include a component filter made of polyethersulfone having an average pore size of about 2.0 μm. In another example, the solid matter filter 502 may comprise a component filter made of nylon 6 having an average pore size of about 0.1 μm. In another example, the solid matter filter 502 may comprise a component filter made of nylon 66 having an average pore size of about 0.8 μm. In another example, the solid matter filter 502 may comprise a component filter made of a mixed cellulose ester having an average pore size of about 1.6 μm.

In some embodiments, the filtration system 500 includes one or more moisture filters 504. The moisture filter 504 may reduce or remove liquids, such as water, in the gas and/or liquid phases. In some embodiments, the moisture filter 504 comprises a membrane filter. In some embodiments, the membrane filter comprises a polymeric material. The polymeric material may have a porous structure. The polymeric material may absorb liquid vapors and/or liquid droplets. Additionally or alternatively, the polymeric material may be at least partially permeable to liquid vapor and/or liquid droplets. For example, the membrane filter may comprise Nafion ^TM And (3) a film.

In some embodiments, the filtration system 500 includes one or more additional filters 506. A filter 506 may be disposed downstream of the solids filter 502 and/or the moisture filter 504 to further remove or reduce impurities, such as moisture and/or solids, from the product gas. In some embodiments, filter 506 comprises a membrane filter. In some embodiments, the membrane filter comprises a polymeric material. In some embodiments, the membrane filter has a porous structure. For example, the polymeric material of the membrane filter may have a porous structure. The average pore size of the porous structure may range from about 0.01 μm to about 2 μm, such as from about 0.01 μm to about 0.1 μm, from about 0.1 μm to about 0.2 μm, from about 0.2 μm to about 0.3 μm, from about 0.3 μm to about 0.4 μm, from about 0.4 μm to about 0.5 μm, from about 0.5 μm to about 1.0 μm, from about 1.0 μm to about 2 μm, or a combination thereof. In some embodiments, the average pore size of filter 506 is equal to or less than the average pore size of solid matter filter 502.

As described herein, a membrane filter used in some embodiments of the present disclosure may include at least one membrane, which may have any suitable configuration for filtering or separating gases, liquids, and/or solids. For example, the membrane of a membrane filter may be configured for dead-end filtration, wherein a fluid may pass through the membrane and components to be separated from the fluid may be blocked or captured by the membrane. Alternatively, the membranes of the membrane filter may be configured for cross-flow filtration, wherein the fluid may pass through the surface of the membrane on the feed side, and the components to be separated from the fluid may remain on the feed side or permeate through the membrane to the permeate side. An example configuration of cross-flow filtration is one or more hollow fibers formed from membranes.

For example, the product gas output from the gas region 110 of the NO generating device 100 may comprise a certain amount of liquid impurities and/or solid impurities, such as water and salt aerosols. Such amounts of impurities may damage and/or affect the life of downstream devices, such as pump 306 and one or more of filters 502-506. In some embodiments, the system 500 comprises a filtering means 508 arranged downstream of the NO generating device 100. In some embodiments, a filtration device 508 is disposed upstream of the pump 306 to reduce or remove liquid and/or solid impurities in the recycled product gas 303. For example, the product gas output from the gas region 110 of the NO generation device 100 may include one or more impurities, such as water or droplets of reaction medium 112 or steam. In some embodiments, the filter device 508 is disposed upstream of the solid matter filter 502 and/or the moisture filter 504. The filtering device 508 may reduce or remove liquid and/or solid impurities from the product gas before the product gas flows through one or more of the filters 502-506.

Fig. 5A-5C illustrate a filter device 508 according to some embodiments of the present disclosure. As shown in fig. 5A-5C, in some embodiments, the filter device 508 includes a housing 510, an inlet 518, and an outlet 520. In some embodiments, the filter device 508 includes at least one chamber disposed in the housing 510. The inlet 518 and/or the outlet 520 may be in fluid communication with at least one chamber in the housing 510. The housing 510 may have any suitable shape, such as a cylindrical shape. As shown in fig. 5C, an inlet 518 may be provided at a bottom portion of the housing 510 in fluid communication with the chamber. An outlet 520 may be provided at a top portion of the housing 510 in fluid communication with the chamber.

In some embodiments, as shown in fig. 5B, the filter apparatus 508 includes one or more filter chambers 512. The filter chamber 512 may have any suitable shape, such as a cylindrical shape. The filter chambers 512 may be disposed about the longitudinal axis of the housing 510 and may be equally spaced or unequally spaced. The filter arrangement 508 may include any suitable number of filter chambers 512, such as 2 to 5 filter chambers. For example, three filter chambers 512 may be equally spaced about 120 degrees apart about the longitudinal axis of the housing 510.

Each filter chamber 512 may have an inlet 522 and an outlet 524. The inlet and outlet of the one or more filter chambers 512 may define a flow path. One or more filter chambers 512 (e.g., a first filter chamber 512) may have an inlet 522 in fluid communication with an inlet 518 of the housing 510. One or more filter chambers 512 (e.g., the last filter chamber 512) may have an outlet 524 in fluid communication with the outlet 520 of the housing 510. In some embodiments, filter chamber 512 includes a filter material 516 configured to reduce or remove one or more impurities in a fluid flowing therethrough. The filter material 516 may fill at least a portion of the filter chamber 512, such as a middle portion of the filter chamber 512. The filter material 516 may include any suitable material, such as silica gel, sponge, cotton, polypropylene (e.g., PP cotton filter), foam, and foam resin.

In some embodiments, the filter device 508 includes a feed chamber 526. The feed chamber 526 may be in fluid communication with the inlet 518 for receiving a fluid, such as a gas stream, to be filtered. The feed chamber 526 may be in fluid communication with one or more filter chambers 512. For example, the feed chamber 526 may have an outlet in fluid communication with the inlet 522 of the filter chamber 512. In some embodiments, the feed chamber 526 extends through a middle portion of the housing 510 such that a cavity is formed between the feed chamber 526 and an inner surface of the housing 510.

For example, as shown in fig. 5A-5C, the housing 510 may have a cylindrical shape. The feed chamber 526 may have a cylindrical shape extending along at least a portion of the longitudinal axis of the housing 510. The annular space formed between the feed chamber 526 and the housing 510 may form a cavity. In some embodiments, one or more chambers (such as filter chamber 512) are disposed in the cavity between the feed chamber 526 and the housing 510.

The filtration device 508 may be configured to allow at least some liquid impurities and/or solid impurities in a gas (such as a product gas output from the gas region 110) to be separated from the gas based on, for example, gravity settling or separation. In some embodiments, the inlet 522 of the filter chamber 512 is disposed vertically below the outlet 524 such that liquid and/or solid particles suspended in the gas flowing from the inlet 522 to the outlet 524 may settle out of the gas and may settle to the bottom of the filter chamber 512.

For example, the filter chamber 512 may have an elongated shape (e.g., a cylindrical shape) and may be disposed in an upright position along its longitudinal axis. In this configuration, the inlet 522 may be disposed at a bottom or lower portion of the filter chamber 512, while the outlet 524 may be disposed at a top or upper portion of the filter chamber 512. The flow of gas may enter the filter chamber 512 from the inlet 522, move or rise through at least a portion of the filter chamber 512, to the outlet 524. As the gas stream moves or rises in the filter chamber 512, the gas stream may pass through the filter material 516 and liquid and/or solid impurities suspended in the gas stream may settle out and separate from the gas stream.

In some embodiments, the filter apparatus 508 includes a buffer chamber 514 in fluid communication with the filter chamber 512. For example, the buffer chamber 514 may be fluidly connected to the filter chamber 512 via an opening or port at a bottom portion of the filter chamber 512. The gas to be filtered (e.g., a gas flow) may flow from the buffer chamber 514 to the filter chamber 512 via an opening or port, rise in the filter chamber 512, and exit from the outlet 524. Liquid and/or solid matter that settles out of the gas in the filter chamber 512 may settle to the bottom portion of the filter chamber 512. Settled liquids and/or solids may flow to and accumulate in buffer chamber 514.

The accumulated liquid and/or solid material in buffer chamber 514 may be transported out of filter device 508 by any suitable means, such as by gravity or by a pump. The liquid and/or solid material carried out of the filter device 508 may be disposed of or reused. For example, reaction medium 112 that has settled out of the product gas from NO generation apparatus 100 may be transported from buffer chamber 514 back to liquid region 108 of reaction chamber 102 and reused.

In some embodiments, as shown in fig. 5C, the buffer chamber 514 is in fluid communication with the feed chamber 526. Fluid may flow from the feed chamber 526 to the buffer chamber 514 and from the buffer chamber 514 to the filter chamber 512. For example, a fluid to be filtered (such as a gas stream) may flow from the inlet 518, through the feed chamber 526, the buffer chamber 514, and the filter chamber 512, and to the outlet 520.

In some embodiments, as shown in fig. 5A-5C, the filter apparatus 508 includes two or more fluidly connected filter chambers 512 to allow for more than one settling process. For example, the outlet 524 of the first filter chamber 512 may be fluidly connected with the inlet 522 of the second filter chamber 512. The gas may flow through two or more filter chambers 512 to allow liquid and/or solid impurities to settle out of the gas flow as the gas flow rises from the inlet 522 to the outlet 524 of each filter chamber.

In some embodiments, as shown in fig. 5A and 5B, the buffer chamber 514 fluidly connects two filter chambers 512. The buffer chamber 514 may have an opening or conduit configured to connect with two filter chambers 512 such that fluid may flow from an inlet 522 to an outlet 524 in each of the two filter chambers 512. For example, as shown in fig. 5B, the outlet 524 of the first filter chamber 512 may be the inlet of the buffer chamber 514, and the inlet 522 of the second filter chamber 512 may be the outlet of the buffer chamber 514. Fluid may flow from the outlet 524 of the first filter chamber 512 to the buffer chamber 514 and from the buffer chamber 514 to the inlet 522 of the second filter chamber 512. In this case, as shown in fig. 5B, the outlet 524 of the first filter chamber 512 may be provided at a top portion of the buffer chamber 514, and the inlet 522 of the second filter chamber 512 may be provided at a bottom portion of the buffer chamber 514.

The filter device 508 may include one or more other components, such as components for covering or sealing one or more inlets, outlets, and/or chambers in the housing 510. In some embodiments, as shown in fig. 5A, the filter device 508 includes a seal configured to cover a top side of the buffer chamber 514 to allow gas in the buffer chamber 514 to flow from the buffer chamber 514 to the one or more filter chambers 512. In some embodiments, as shown in fig. 5A, the filter device 508 includes a cover 528. The cover 528 may cover a top side of the housing 510 and may cover a top side of the filter chamber 512 to allow gas in the filter chamber 512 to exit at the outlet 524. Cover 528 may be secured to housing 510 via any suitable connection, such as by a press fit or using a suitable fastening device (e.g., screw fastener). In some embodiments, as shown in fig. 5A, the filter device 508 includes a seal ring configured to form a seal around the inlet 518.

Pressure vessel

The flow rate and/or NO concentration of the product gas generated by the NO generation device 100 may vary due to changes in one or more conditions, such as temperature, current or voltage applied to the electrode, side reactions, electrode degradation, or changes in the concentration of nitrite source and catalyst in the reaction medium 112. The system 10 may include one or more devices or systems (such as pressure vessels) to stabilize the flow and/or NO concentration of the product gas generated by the NO generating apparatus 100. Such a device or system may allow the system 10 to provide a stable NO supply.

In some embodiments, as shown in FIG. 1, the system 10 includes a pressure vessel 600. The pressure vessel 600 may be arranged downstream of and in fluid connection with the NO generating device 100. In some embodiments, the pressure vessel 600 receives product gas from the outlet circuit 124 of the NO generation device 100. One or more filters of the filtration system 500 may be arranged downstream of the NO generating device 100 and upstream of the pressure vessel 600. The product gas from the NO generation apparatus 100 may flow from the outlet circuit 124 to the pressure vessel 600 through one or more filters of the filtration system 500. The filtration system 500 may reduce or remove one or more impurities, such as moisture and/or solid matter (e.g., salt aerosols), in the product gas prior to the product gas entering the pressure vessel 600.

In some embodiments, as shown in fig. 6A, the pressure vessel 600 includes a body 602, a gas inlet 612, and a gas outlet 614. The body 602 may have any suitable shape configured to enclose an internal cavity, such as a cylindrical shape. The gas inlet 612 and the gas outlet 614 are in fluid connection with the internal cavity of the body 602. For example, as shown in fig. 6A, the gas inlet 612 and/or the gas outlet 614 may each have an opening or port provided on the body 602.

The pressure vessel 600 may receive and store the product gas from the NO generating device 100 during a pressure maintenance period. At the end of the pressure maintenance period, the pressure in the pressure vessel 600 may be increased to a predetermined level or predetermined range. Additionally or alternatively, at the end of the pressure maintenance period, the concentration of NO in the product gas contained in the pressure vessel 600 may be increased to a predetermined level or predetermined range. The pressure retention period may be predetermined and/or adjusted. In some embodiments, after the pressure maintenance period, the product gas may be released from the pressure vessel 600. The NO concentration of the product gas released from the pressure vessel 600 may increase during the ramp period and may reach steady state at or after the end of the ramp period.

In some embodiments, the pressure vessel 600 is configured to shorten the pressure maintenance period and the ramp period to allow a more rapid or immediate provision of a stable NO supply. For example, the pressure vessel 600 may include one or more flow paths in an interior cavity of the body 602. The one or more flow paths may include a tortuous flow path, such as a serpentine flow path. The one or more flow paths may allow the pressure and/or NO concentration of the product gas in at least a portion of the internal cavity of the body 602 to quickly reach steady state. For example, one or more flow paths may allow new gas (such as product gas) to enter the internal cavity to quickly purge or deplete old gas (such as air or nitrogen) previously present in at least a portion of the internal cavity. Additionally or alternatively, one or more flow paths may reduce or eliminate uneven mixing of new gas with old gas.

As described herein, a tortuous flow path (such as a serpentine flow path) may refer to an indirect flow path that extends in three dimensions along any direction from a first point to a second point. For example, a tortuous flow path may refer to an indirect flow path extending from a first point to a second point through a cross-section and/or longitudinal plane of the pressure vessel 600.

For example, the pressure vessel 600 may allow a pressure retention period of less than about 60 minutes, such as less than about 1 minute, less than about 5 minutes, less than about 10 minutes, less than about 20 minutes, less than about 30 minutes, less than about 40 minutes, or less than about 50 minutes. For example, the pressure vessel 600 may allow a ramp period of less than about 20 minutes, such as less than about 1 minute, less than about 2 minutes, less than about 3 minutes, less than about 4 minutes, less than about 5 minutes, less than about 8 minutes, or less than about 10 minutes.

Fig. 6A-6C are various views of a pressure vessel 600 according to some embodiments of the present disclosure. In some embodiments, the pressure vessel 600 includes one or more panels or baffles 604 that define a plurality of fluidly connected regions within the interior cavity. In various configurations, the fluidly connected regions may form a tortuous flow path, such as a serpentine flow path, through the pressure vessel 600. For example, the plurality of panels 604 may divide the interior cavity into a first region 606 and a second region 608. The first region 606 and the second region 608 may be fluidly connected via, for example, openings, ports, or conduits. Fluid (e.g., product gas) entering the pressure vessel 600 may enter the first region 606 and may flow from the first region 606 to the second region 608 through a tortuous flow path. Alternatively, a fluid (such as a product gas) entering the pressure vessel 600 may enter the first region 606 and may leave the pressure vessel without flowing into or through the second region 608, i.e., may bypass the second region 608. The tortuous flow path may allow fresh gas entering the pressure vessel 600 to effectively purge or deplete the pressure vessel of the old gas previously present. The tortuous flow path may also allow the pressure in one or more regions of the pressure vessel 600 to reach steady state in a period of time that is shorter than the time required to allow the pressure in the entire pressure vessel to reach steady state.

In some embodiments, the first region 606 is in fluid connection with a gas inlet 612 and a gas outlet 614. For example, the gas inlet 612 may be fluidly connected to a first opening or port disposed in the first region 606. The gas outlet 614 may be fluidly connected to a second opening or a second port disposed in the first region 606. The gas may flow from the gas inlet 612 to the gas outlet 614 via at least a portion of the first region 606.

The first region 606 may be configured to allow gas entering the gas inlet 612 to quickly fill at least a portion of the first region 606. In some embodiments, the first region 606 is divided into a plurality of chambers defining a first flow path 618. For example, one or more panels 604 may be disposed in a first region 606 and divide the first region into a plurality of chambers. The first flow path 618 may be a tortuous flow path, such as a serpentine flow path. The tortuous flow path may allow fresh gas entering the first region 606 to quickly purge or deplete old gas previously present in one or more chambers of the first region 606. This may allow the pressure in one or more chambers of the first region 606 to reach steady state in a shorter period of time than the time required to allow the pressure in one or more chambers of the first region 606 and the second region 608 to reach steady state. For example, it may take less than about 5 minutes for one or more of the chambers of the first region 606 to reach steady state pressure, but it may take about 20 to about 30 minutes for the internal cavity of the body 602 of the pressure vessel 600 to reach steady state pressure.

For example, as shown in fig. 6B and 6C, a gas inlet 612 and a gas outlet 614 may be fluidly connected to the first chamber 606 a. The product gas may flow from the gas inlet 612 to the gas outlet 614 via at least a portion of the first chamber 606 a. The product gas received by the gas inlet 612 may enter and rapidly fill the first chamber 606a of the first region 606, allowing the pressure in the first chamber 606a to reach a steady state in a short period of time. This may reduce the pressure hold time before the product gas is released from the gas outlet 614.

The first chamber 606a may have any suitable shape and/or size that allows the pressure of the product gas in the chamber to reach steady state in a short pressure hold time. For example, the first chamber 606a may have an elongated shape and a narrow cross-section extending along a longitudinal dimension of the body 602. The first chamber 606a may have any suitable size or volume. For example, the first chamber 606a may have a volume that is 50% or less of the internal cavity of the body 602. For example, the pressure vessel 600 may have an internal volume of about 800mL, and the first chamber 606a may have a volume of about 10mL to about 200 mL. In one example, after a pressure hold period of about 20 minutes to receive and hold the product gas, the pressure vessel 600 may release the product gas at the gas outlet 614, and the NO concentration in the released product gas may reach steady state within about 10 minutes.

In some embodiments, the second region 608 is fluidly connected to the first region 606 via a channel 610. The second region 608 can receive and store gas flowing from the first region 606. The second region 608 may include a tortuous flow path, such as a serpentine flow path. For example, the second region 608 may be configured to allow gas from the first region 606 to fill at least a portion of the second region 608.

In some embodiments, the second region 608 is divided into a plurality of chambers defining a second flow path 620. For example, one or more panels 604 may be disposed in the second region 608 and divide the second region into a plurality of chambers. The second flow path 620 may be in fluid communication with the first flow path 618, for example, via the channel 610. The second flow path 620 and the first flow path 618 may form a continuous flow path. The second flow path 620 may be a tortuous flow path, such as a serpentine flow path. The tortuous flow path may allow fresh gas entering the second region 608 from the first region 606 to purge or deplete old gas previously present in one or more chambers of the second region 608. This may also allow the pressure in one or more chambers of the second region 608 to reach a steady state before the pressure in the entire second region 608 reaches a steady state.

The chamber of the second region 608 may be referred to as a gas storage unit. One or more of the plurality of chambers of the second region 608 may be further divided into one or more subchambers to further reduce the volume in each gas storage unit. This may reduce or eliminate uneven mixing of the new gas with the old gas in the second region 608, and this may reduce the time required for the pressure in the second region 608 to reach steady state. For example, the chambers of the second region 608 may each be divided into two or more fluidly connected subchambers by one or more dividers 609. The divider 609 may have any suitable structure for directing the flow of gas in the chamber, such as a panel or plate. For example, as shown in fig. 6B and 6C, two or more dividers 609 may each extend along at least a portion of the longitudinal axis of the pressure vessel 600 and may be radially spaced apart such that the subchambers are fluidly connected via the spaces 611 between the dividers.

As described herein, the fluidly connected chambers in the first region 606 or the second region 608 may have any suitable configuration to define a flow path that allows new gas to purge or deplete pre-existing old gas in one or more chambers of the region. For example, as shown in fig. 6C, the inlet and outlet of a chamber (such as first chamber 606 a) may be separately disposed along at least one dimension (such as a horizontal and/or longitudinal dimension). This configuration may allow fresh gas entering the chamber to flow through the chamber from the inlet to the outlet along at least one dimension to purge or deplete the chamber of the old gas that previously existed.

The second region 608 may serve as a reservoir for storing product gas. For example, when the flow rate of the product gas received at the gas inlet 612 is higher than the flow rate of the product gas released at the gas outlet 614, additional product gas may flow from the first region 606 to the second region 608 to be stored. When the flow rate of the product gas received at the gas inlet 612 is lower than the flow rate of the product gas released at the gas outlet 614, the product gas stored in the second region 608 may flow from the second region 608 to the first region 606 to supplement the product gas flow. In this case, the pressure vessel 600 may reduce variations in the pressure, flow rate, and/or NO concentration of the product gas released at the gas outlet 614. This may be advantageous to provide a stable NO supply, such as in cases where NO generation may vary due to various conditions. It may also be advantageous to provide the NO supply at a desired pressure, flow rate and/or concentration as needed. The second region 608 may also be used as a back-up source for NO. For example, in response to an abnormality in the NO generation device 100 generating NO and/or transporting NO in the system 10, the product gas stored in the second region 608 may be released to continue or supplement the supply of NO.

In some embodiments, pressure vessel 600 includes a pressure relief valve 622. The pressure relief valve 622 is configured to control the pressure in the pressure vessel 600 not to exceed a threshold value. The threshold may be a predetermined safety threshold. The pressure relief valve 622 may be normally closed, such as by the force of a spring. The pressure relief valve 622 may be opened when the pressure in one or more areas of the pressure vessel 600 exceeds a threshold. In some embodiments, pressure relief valve 622 is in fluid communication with second region 608. As shown in fig. 1, the product gas released from pressure release valve 622 may be transported from pressure vessel 600 to exhaust treatment device 700.

In some embodiments, the system 10 includes one or more pressure sensors to measure pressure in one or more areas or chambers in the pressure vessel 600. In some embodiments, the pressure sensor 624 may be configured to measure a pressure in the first region 606, such as a pressure in the first chamber 606a of the first region 606. The measurement of pressure sensor 624 may be indicative of the pressure of the product gas released from gas outlet 614 to a downstream system or device. In some embodiments, one or more pressure sensors (not shown) may be configured to measure pressure in the second region 608. The measurement of such a pressure sensor may be indicative of the amount of product gas stored in the second region 608.

In some embodiments, pressure vessel 600 includes purge valve 626. Purge valve 626 may be used to purge or exhaust gases, such as product gases, in one or more areas in the interior cavity of pressure vessel 600. For example, the purge valve 626 may be in fluid communication with the first region 606 or the second region 608. As shown in fig. 1, the product gas released from the purge valve 626 may be transported from the pressure vessel 600 to an exhaust treatment device 700. In some embodiments, as shown in fig. 1, an NO sensor 628 is disposed downstream of the purge valve 626 and is configured to measure the NO concentration of the product gas released from the purge valve 626. The measurement of the NO sensor 628 may indicate whether the product gas has been purged or exhausted from one or more areas of the pressure vessel 600.

In some embodiments, as shown in FIG. 1, the system 10 includes one or more flow control devices 630 to control the flow of product gas released from the pressure vessel 600. A flow control device 630 may be disposed downstream of and in fluid communication with the gas outlet 614. The flow control device 630 may include a flow meter and/or a flow controller, such as a flow control valve. In some embodiments, the system 10 includes a first flow control device 630 and a second flow control device 630. The first flow control device 630 may be selected to measure and/or adjust flow in a first range and the second flow control device 630 may be selected to measure and/or adjust flow in a second range that is lower than the first range. The flow control device 630 may be in communication with and/or controlled by one or more other components of the system 10, such as the ventilation circuit 900, as described below.

Exhaust gas treatment

The system 10 may generate exhaust before, during, and/or after NO generation and/or delivery. For example, waste gases may be generated during the separation of NO from reaction medium 112 by liquid-gas separation device 408. Further, for example, releasing the product gas from the pressure release valve 622 of the pressure vessel 600 may generate an exhaust gas. The exhaust of the system 10 may include one or more components such as NO, carrier gas, moisture, and other oxides of nitrogen that may be generated during NO generation and/or transport. For example, during NO generation or transport in system 10, NO may be oxidized to nitrogen dioxide (NO ₂ )。

Nitrogen oxides (also known as NO) _x ) Such as NO and NO ₂ If released directly from the system 10 into the environment, air pollution and/or health risks may result. In some embodiments, as shown in FIG. 1, the system 10 includes one or more exhaust treatment devices700 to treat the exhaust gas prior to releasing the exhaust gas from the system 10. The exhaust treatment device 700 may reduce or remove one or more nitrogen oxides in the exhaust gas, thereby reducing or eliminating potential air pollution and/or risk of exposure to nitrogen oxides.

In some embodiments, the exhaust treatment device 700 is disposed downstream of and in fluid communication with the liquid-gas separation device 408. The exhaust treatment device 700 may receive the mixed gas from an outlet 426 of the liquid-gas separation device 408. The mixed gas may include a sweep gas and one or more oxides of nitrogen (such as NO and NO ₂ ). In some embodiments, the exhaust treatment device 700 is disposed downstream of the pressure vessel 600 and in fluid communication with the pressure relief valve 622. When the pressure in pressure vessel 600 reaches or exceeds a threshold, exhaust treatment device 700 may receive the product gas released from pressure release valve 622. The product gas may include a carrier gas and one or more nitrogen oxides (such as NO and NO ₂ )。

In some embodiments, the off-gas from the pressure vessel 600 and the liquid-gas separation device 408 may be treated by the same off-gas treatment device 700. For example, the system 10 may include a three-way connector 702 disposed upstream of the exhaust treatment device 700 and downstream of the pressure vessel 600 and the liquid-gas separation device 408. The exhaust gases from the pressure vessel 600 and the liquid-gas separation device 408 may be combined at a three-way connector 702 and flow to the same exhaust treatment device 700. The three-way connector 702 may include any suitable structure, such as a three-way fitting or a three-way valve.

In some embodiments, the exhaust treatment device 700 reduces or removes one or more nitrogen oxides in the exhaust as the exhaust passes through the exhaust treatment device 700. In some embodiments, the exhaust treatment device 700 includes a body, an inlet, and an outlet. The inlet and outlet are in fluid communication with a cavity defined by the body. In some embodiments, at least a portion of the cavity is filled with a filter material that can reduce or remove one or more oxides of nitrogen as the exhaust gas passes through the filter material. For example, the filter material may include a material configured to absorb a One or more nitrogen oxides NO _x (e.g. NO and NO ₂ ) Is a material that is absorbent.

In some embodiments, the absorbent material includes a substrate prepared with an absorbent that can react with one or more nitrogen oxides. For example, the substrate may be coated with an oxidizing agent. The substrate may have any suitable configuration to provide a surface area for the absorber to react with the one or more nitrogen oxides. For example, the substrate may include one or more materials selected from the group consisting of molecular sieves, silica gel, alumina, sponge, cotton, foam resin, silica, and activated carbon. For example, the absorbent may comprise one or more materials selected from permanganate, persulfate, chromate, and dichromate.

In some embodiments, the exhaust treatment device 700 includes a plurality of baffles configured to define a fluid path. In some embodiments, at least a portion of the flow path is filled with a filter material. The flow path may be a tortuous flow path, such as a serpentine flow path. For example, a plurality of baffles may extend from the wall of the cavity in an alternating fashion to define a serpentine flow path. The tortuous flow path may extend along one or more dimensions. The tortuous flow path may increase contact between the exhaust gas and the filter material to allow for reduction or removal of more nitrogen oxides as the exhaust gas passes through the device.

Fig. 7A-7C are various views of an exhaust treatment device 700 according to some embodiments of the present disclosure. As shown in fig. 7A-7C, in some embodiments, the exhaust treatment device 700 includes a body 703, an inlet 722, and an outlet 724. Inlet 722 and outlet 724 are in fluid communication with cavity 706 defined by body 703. The body 703 may have any suitable shape, configuration, and/or size. For example, the body 703 may have a cylindrical shape.

In some embodiments, body 703 has a first side 718 and a second side 720. The inlet 722 and the outlet 724 may be provided on opposite sides or the same side of the body 703. For example, inlet 722 may be disposed on first side 718, while outlet 724 may be disposed on second side 720. Alternatively, both the inlet 722 and the outlet 724 may be disposed on the first side 718 or the second side 720. In some embodiments, body 703 includes an inner shell 708 and an outer shell 710 extending from a first side 718 to a second side 720. The inner housing 708 and the outer housing 710 may define an annular cavity 706. The inner housing 708 and the outer housing 710 may have any suitable dimensions. For example, the outer shell 710 may range in diameter from 120mm to 160mm, while the inner shell 708 may range in diameter from 80mm to 120mm.

In some embodiments, as shown in fig. 7C, the cavity 706 is separated by a wall 716 that extends between the inner housing 708 and the outer housing 710 and from a first side 718 to a second side 720. Inlet 722 and outlet 724 may be disposed adjacent opposite sides of wall 716. At least a portion of the cavity 706 may be filled with a filter material (not shown). Exhaust passing through exhaust treatment device 700 may flow from inlet 722 through chamber 706 to outlet 724.

In some embodiments, the exhaust treatment device 700 includes a plurality of baffles. The plurality of baffles may have any configuration that defines a tortuous flow path 704 (such as a serpentine flow path) in the cavity 706. In some embodiments, as shown in fig. 7C, a first set of baffles 712 may extend between a first side 718 and a second side 720 and from the inner shell 708 toward the outer shell 710, while a second set of baffles 714 may extend between the first side 718 and the second side 720 and from the outer shell 710 toward the inner shell 708. The baffles 712 and 714 may extend any suitable distance between the inner housing 708 and the outer housing 710 to direct the exhaust flow. For example, the distance between the spacer 712 and the outer housing 710 and/or the distance between the spacer 714 and the inner housing 708 may be in the range of 2mm to 8 mm.

In some embodiments, the first set of baffles 712 and the second set of baffles 714 may be arranged in an alternating fashion. For example, as shown in fig. 7C, a first set of baffles 712 may be evenly distributed around the circumference of the inner shell 708, while a second set of baffles 714 may be evenly distributed around the circumference of the outer shell 710, offset from the first set of baffles 712. The exhaust treatment device 700 may include any suitable number of baffles, such as 2 to 16 baffles. For example, the number of first set of baffles 712 and/or second set of baffles 714 may be in the range of 2 to 8. The number of first set of baffles 712 and second set of baffles 714 may or may not be the same. It is contemplated that exhaust treatment device 700 may include any suitable number of baffles with or without the provision of suitable filter materials.

Exhaust gas may flow from inlet 722 to outlet 724 through tortuous flow path 704. The tortuous flow path 704 may be filled with a filter material. As the exhaust gas passes through the filter material in the flow path 704, one or more nitrogen oxides in the exhaust gas may be absorbed. The exhaust may exit the exhaust treatment device 700 from the outlet 724 and may be released into the environment with or without further treatment.

Reduction and/or removal of toxic nitrogen oxides

NO can be oxidized to one or more toxic nitrogen oxides (such as NO ₂ ) If these toxic nitrogen oxides are delivered to the patient with NO, health risks may be presented. In some embodiments, the system 10 includes a gas converter 800. The gas converter 800 may remove some or all of the potentially toxic nitrogen oxides (such as NO) that may be present in the product gas as the product gas passes through the gas converter ₂ ) Converted to NO. The gas converter 800 may reduce the potential risk of exposure to toxic nitrogen oxides and may increase NO production by converting other nitrogen oxides in the product gas back to NO.

In some embodiments, the gas converter 800 is disposed downstream of and in fluid communication with the NO generating device 100. In some embodiments, the gas converter 800 is disposed downstream of and in fluid communication with the filtration system 500. In some embodiments, the gas converter 800 is disposed downstream of and in fluid communication with the pressure vessel 600. Fig. 8A is an exploded view of a gas converter according to some embodiments of the present disclosure. In some embodiments, as shown in fig. 8A, the gas converter 800 includes a body 808, an inlet 818, and an outlet 820. The inlet 818 and the outlet 820 are in fluid communication with the cavity defined by the body 808. The body 808 may have any suitable shape. In some embodiments, the body 808 has a cylindrical shape extending between a first side and a second side. Two end caps 806 may cover the first side and the second side of the body 808. Inlet 818 and outlet 820 may be provided at the same end cap 806 or at different end caps 806.

In some embodiments, gas converter 800 includes one or more membrane filters 810 and a filter holder 812. Filter holder 812 can be configured to position membrane filter 810 between end cap 806 and body 808. Membrane filter 810 may reduce or remove one or more impurities, such as moisture and solid matter, in the product gas entering and/or exiting gas converter 800.

In some embodiments, at least a portion of the cavity is filled with a filter material that can absorb one or more toxic nitrogen oxides, such as NO, as the product gas passes through the filter material ₂ . For example, the filter material may comprise particles of soda lime. In some embodiments, at least a portion of the cavity is filled with a filter material that can pass one or more toxic nitrogen oxides (such as NO ₂ ) Converted to NO. In some embodiments, the filter material includes a substrate configured to carry a reducing agent. For example, the surface of the substrate may be prepared with a reducing agent, such as applied, treated or coated. The reducing agent may react with one or more nitrogen oxides and reduce them to NO. The substrate may have any suitable configuration to provide a surface area for supporting the reducing agent. For example, the substrate may comprise one or more materials selected from molecular sieves, silica gel, alumina, sponge, cotton, foam resin. For example, the reducing agent may include one or more antioxidants, such as vitamin a, vitamin E, and vitamin C. As used herein, vitamin C may also be referred to as ascorbic acid or ascorbate.

The filter material may be prepared using any suitable method or process. For example, an amount of one or more reducing agents may be prepared as a solution. The solution may be an aqueous or organic solution, and the solution may be a saturated solution of one or more reducing agents. A quantity of substrate may be added to the solution and mixed homogeneously. The substrate may then be removed from the solution and dried at a drying temperature for a period of time to allow the solvent to evaporate. Any suitable amount of reducing agent and substrate may be selected based on one or more conditions, such as the type of material used and the desired reducing capacity. For example, an amount of reducing agent in the range of about 5g to about 50g may be used to prepare a substrate having a weight of about 100g per serving.

In one example, an amount of about 25g of vitamin C may be used to coat each serving of about 100g of alumina particles. In another example, an amount of about 5g vitamin A can be used to prepare cotton in an amount of about 100g per serving. In another example, an amount of about 5g vitamin E may be used to prepare a foam resin in an amount of about 100g per serving. In another example, an amount of about 30g of vitamin C can be used to prepare a molecular sieve in an amount of about 100g per serving. In another example, an amount of about 20g of vitamin A may be used to prepare a sponge material in an amount of about 100g per serving. In another example, an amount of about 15g vitamin E may be used to prepare a silica gel of about 100g per serving.

The drying temperature may range from about 40 ℃ to about 150 ℃, such as from about 40 ℃ to about 50 ℃, from about 50 ℃ to about 60 ℃, from about 60 ℃ to about 70 ℃, from about 70 ℃ to about 80 ℃, from about 80 ℃ to about 90 ℃, from about 90 ℃ to about 100 ℃, from about 100 ℃ to about 110 ℃, from about 110 ℃ to about 120 ℃, from about 120 ℃ to about 130 ℃, from about 130 ℃ to about 140 ℃, from about 140 ℃ to about 150 ℃, or a combination thereof. The drying time may range from about 0.1h to about 10h, such as from about 0.1h to about 0.2h, from about 0.2h to about 0.5h, from about 0.5h to about 1h, from about 1h to about 2h, from about 2h to about 3h, from about 3h to about 4h, from about 4h to about 5h, from about 5h to about 6h, from about 6h to about 7h, from about 7h to about 8h, from about 8h to about 9h, from about 9h to about 10h, or a combination thereof.

In some embodiments, as shown in fig. 8A-8B, the cavity of the gas converter 800 is divided into a plurality of chambers 816, each having an inlet and an outlet. The inlet of the first chamber may be fluidly connected to inlet 818 and the outlet of the last chamber may be fluidly connected to outlet 820. The inlet and outlet of chamber 816 may be fluidly connected to define flow path 802. The filter material may fill at least a portion of each chamber, such as from an inlet to an outlet of the chamber. The inlet and outlet of each chamber may be provided at opposite ends such that gas passing through the chamber may flow from the inlet, through the chamber, through the filter material, to the outlet.

The flow path 802 may be a tortuous flow path, such as a serpentine flow path. The tortuous flow path in the cavity of the body 808 may increase contact between the product gas and the filter material to allow more nitrogen oxides to be reduced to NO as the product gas passes through the device for a given cavity volume.

The chambers in the cavity of gas converter 800 may have any suitable configuration. For example, one or more panels 814 can be disposed in both sides of the body 808 and extend therebetween. The panels 814 may be equally spaced or unequally spaced about the longitudinal axis of the body 808. The panels 814 may each extend radially from the longitudinal axis to an inner wall of the body 808. For example, the panel 814 can uniformly divide the cavity into a plurality of elongated chambers 816 that extend between two sides of the body 808 and are disposed about a longitudinal axis of the body 808. Any suitable number of panels 814 may be used. For example, if the panels 814 are arranged about the longitudinal axis of the body 808, an odd number of panels 814 may divide the cavity into an odd number of chambers, and the inlet 818 and the outlet 820 may be disposed at opposite end caps 806. Alternatively, an even number of panels 814 may divide the cavity into an even number of chambers, and inlet 818 and outlet 820 may be provided at the same end cap 806.

In one example, the cavity of gas converter 800 may be uniformly divided into three elongated chambers, as shown in fig. 8A-8B. Each chamber may be filled with a filter material. For example, it is possible to use aluminum silica gel particles having an average diameter of about 0.2mm and vitamin CPreparing a filter material. First, about 5 grams of vitamin C may be dissolved in 100 grams of water to prepare a saturated aqueous solution of vitamin C. An amount of 100 grams of aluminum silica gel particles may be added to the solution and mixed homogeneously. The aluminum silica gel particles may be dried at about 100 ℃ for about 0.5 hours. The gas converter 800 may be used to treat a gas containing 100ppm NO at a flow rate of 1.0L/min ₂ For a duration of about 90 hours. About 100% of the NO in the gas stream may be removed ₂ Converted to NO.

Alternatively, the filter material may be prepared from silica gel particles having an average diameter of about 3mm and vitamin E. First, about 15 grams of vitamin E can be prepared as a saturated solution. Approximately 100 grams of silica gel particles may be added to the solution and mixed homogeneously. The silica gel particles may be dried at about 50 ℃ for about 5 hours. The gas converter 800 may be used to treat a gas containing 500ppmNO at a flow rate of 4.0L/min ₂ For a duration of about 5 hours. About 100% of the NO in the gas stream may be removed ₂ Converted to NO.

In another example, the cavity of gas converter 800 may be uniformly divided into four elongated chambers, similar to the embodiment shown in fig. 8A-8B. Each chamber may be filled with a filter material. The filter material may be prepared with molecular sieve particles having an average diameter of about 5mm and vitamin a. First, about 25 grams of vitamin a can be prepared as a saturated solution. Approximately 100 grams of molecular sieve particles may be added to the solution and mixed homogeneously. The molecular sieve particles may be dried at about 80 ℃ for about 2 hours. The gas converter 800 may be used to treat a gas containing 200ppmNO at a flow rate of 2.0L/min ₂ For a duration of about 70 hours. About 100% of the NO in the gas stream may be removed ₂ Converted to NO. Alternatively, the filter material may be prepared from alumina particles having an average diameter of about 6mm and vitamin C. About 35 grams of vitamin C can be prepared as a saturated solution. Alumina particles may be added to the solution and mixed homogeneously. The alumina screen particles can be dried at about 120 ℃ for about 0.25 hours. The gas converter 800 may be used to provide a flow of 1.0L/min The amount of treatment contained 500ppmNO ₂ For a duration of about 125 hours. About 100% of the NO in the gas stream may be removed ₂ Converted to NO.

In another example, the cavity of gas converter 800 may be uniformly divided into five elongated chambers, similar to the embodiment shown in fig. 8A-8B. Each chamber may be filled with a filter material. The filter material may be prepared from sponge and vitamin E. About 40 grams of vitamin E can be prepared as a saturated solution. About 100 grams of sponge may be immersed in the solution. The sponge may be dried at about 150 ℃ for about 0.2 hours. The gas converter 800 may be used to treat a gas containing 800ppm NO at a flow rate of 3.0L/min ₂ For a duration of about 12 hours. About 100% of the NO in the gas stream may be removed ₂ Converted to NO. Alternatively, cotton and vitamin A may be used to prepare the filter material. About 50 grams of vitamin a can be prepared as a saturated solution. Approximately 100 grams of cotton may be immersed in the solution. The cotton may be dried at about 70 c for about 3 hours. The gas converter 800 may be used to treat a gas containing 400ppmNO at a flow rate of 4.0L/min ₂ For a duration of 35 hours. About 100% of the NO in the gas stream may be removed ₂ Converted to NO.

In some embodiments, the product gas released from gas converter 800 may be the output gas of system 10. The mass and/or flow of the output gas of the system may be monitored. For example, NO can be monitored ₂ And the concentration of moisture. In some embodiments, a flow meter is utilized to monitor the flow of the output gas of the system 10.

NO delivery and/or monitoring

The NO generated by system 10 may be used in a variety of NO-based therapies. For example, the NO generated by system 10 may be used for NO inhalation therapy. The NO generated by the system 10 may be delivered to the patient with or without another gas, such as oxygen. For example, the NO generated by the system 10 may be delivered to the patient by a flow of air or oxygen provided by a ventilator.

In some embodiments, as shown in fig. 1, the system 10 includes a ventilation circuit 900 for delivering inhaled NO to a patient. In some embodiments, the vent circuit 900 is disposed downstream of and in fluid communication with the pressure vessel 600. The vent circuit 900 may also be disposed downstream of and in fluid communication with the gas converter 800. The ventilation circuit 900 may be configured to connect the system 10 to a respiratory device or system to deliver NO in any suitable form. For example, the ventilation circuit 900 may connect the system 10 to a ventilator, nebulizer, positive airway pressure, oxygen supply, or the like.

Fig. 9 is a schematic diagram of a ventilation circuit 900 of the system 10 according to some embodiments of the present disclosure. In some embodiments, ventilation circuit 900 includes an inhalation circuit 904 and an exhalation circuit 922. The inspiratory circuit 904 may be configured to fluidly connect to the ventilator 906 and deliver a flow of gas (such as an air or oxygen flow) from the ventilator 906 to the patient 910 via a mask or tube. The exhalation circuit 922 may deliver exhaled gas from the patient 910 to the ventilator 906.

In some embodiments, as shown in fig. 9, the ventilation circuit 900 includes a port 902 configured to receive a supply of NO. For example, the port 902 may be disposed along and in fluid communication with an aspiration circuit 904. In some embodiments, port 902 is disposed downstream of and in fluid communication with pressure vessel 600 and/or gas converter 800. The NO supplied from the pressure vessel 600 may be mixed with and/or entrained by oxygen or air flowing through the inspiratory circuit 904 to form a gas mixture 907 for delivery to the patient 910. In some embodiments, a humidifier 908 is disposed downstream of the port 902, and the gas mixture 907 may be humidified by the humidifier 908 prior to delivery to the patient 910.

In some embodiments, the vent circuit 900 includes a flow controller 916. A flow controller 916 may be disposed upstream of the port 902 and configured to control the flow of a gas stream (such as a NO-containing product gas from the pressure vessel 600 or the gas converter 800) into the port 902. The flow controller 916 may include an inlet port, an outlet port, a flow sensor, and a control valve. In some embodiments, the flow controller 916 is a mass flow controller.

In some embodiments, the ventilation circuit 900 includes a control 918. The control 918 may be in communication with the flow controller 916 via a wired connection or a wireless connection. Control 918 may send control signals to flow controller 916 to adjust the flow of the gas stream into port 902. For example, the control device 918 can receive a sensor signal from the flow controller 916 that is indicative of the flow of product gas into the port 902, and the control device can generate a control signal in response to the received sensor signal. Control signals may be sent from the control device 918 to the flow controller 916 to adjust the flow of the gas stream into the port 902.

In some embodiments, the ventilation circuit 900 includes a flow sensor 905 configured to measure the flow of the air flow or oxygen flow output from the ventilator 906. A flow sensor 905 may be disposed along the suction circuit 904, such as upstream of the port 902. The control device 918 may be in communication with the flow sensor 905 via a wired connection or a wireless connection. Control 918 may send control signals to flow controller 916 to adjust the flow of the gas stream into port 902 based on the sensor signals from flow sensor 905. For example, the control device 918 may receive a sensor signal from the flow sensor 905 that is indicative of the flow of the oxygen flow output by the ventilator 906, and the control device may generate a control signal in response to the received sensor signal. A control signal may be sent to the flow controller 916 to adjust the flow of product gas into the port 902 to mix with the oxygen flow, thereby allowing the concentration of NO in the mixed gas delivered to the patient 910 to be adjusted.

In some embodiments, the ventilation circuit 900 includes one or more gas sensors. The gas sensor may be any suitable sensor configured to detect one or more types of gases, and may measure one or more components (e.g., NO ₂ 、O ₂ And moisture). For example, the gas sensor may be electrochemicalA gas sensor, an infrared gas sensor, or a thermally conductive gas sensor.

In some embodiments, the venting circuit 900 includes a sampling port 912. A sampling port 912 may be disposed along and in fluid communication with the inhalation circuit 904 (e.g., downstream of the humidifier 908). The sampling port 912 may be disposed upstream of an applicator (such as a mask or endotracheal tube). The sample gas or sample gas stream from the sample port 912 may be used to measure the concentration of various components of the gas mixture 907.

In some embodiments, one or more gas sensors may be disposed near the sampling port 912, and the one or more gas sensors may communicate with the control device 918 via a wired connection or a wireless connection. In some embodiments, one or more gas sensors are disposed in the gas monitoring apparatus 1100. The sample gas flow may flow from the sampling port 912 through the sampling loop 914 to the gas monitoring device 1100. The gas monitoring device 1100 may communicate with the control device 918 via a wired connection or a wireless connection. One or more of the components indicated (e.g., NO ₂ And O ₂ ) The sensor signal of the concentration of (c) is sent from the gas sensor or from the gas monitoring device 1100 to the control device 918. Control 918 may generate control signals in response to the received sensor signals and may send control signals to one or more components of the system to adjust the concentration of one or more components of gas mixture 907. For example, the control 918 may send control signals to the energy source 114 to adjust the NO concentration or to the flow controller 916 to adjust the NO, NO in the gas mixture 907 ₂ And O ₂ Is a concentration of (3).

The gas monitoring apparatus 1100 may include various features. For example, the gas monitoring apparatus 1100 may include an alarm apparatus configured to detect when one or more measured gas concentrations of the gas mixture 907 exceeds a predetermined threshold (e.g., 25ppm NO, NO ₂ 5 ppm) provide one or more alarms (such as an audible alarm or a visual alarm). The gas monitoring apparatus 1100 may include a display to display alarms andand/or a measured concentration value. Because gas mixture 907 may pass through humidifier 908, the sample gas stream from port 912 may have a high humidity. Reducing or removing moisture in the sample gas stream of gas mixture 907 may improve the accuracy of one or more gas sensors of gas monitoring apparatus 1100.

In some embodiments, the gas monitoring apparatus 1100 includes a moisture collector 1000 configured to reduce or remove moisture in the sample gas stream of the gas mixture 907. Fig. 10A is a perspective view of a moisture collector 1000 according to some embodiments of the present disclosure. Fig. 10B is a partial perspective view of moisture collector 1000. Fig. 10C is another partial perspective view of moisture collector 1000. As shown in fig. 10A-10C, in some embodiments, the moisture collector 1000 includes one or more inlets (such as inlet 1008) and one or more outlets (such as first outlet 1010 and second outlet 1012). A gas flow 1009 (such as a sample gas flow from port 912) may enter the moisture collector 1000 via one or more inlets and the gas flow may exit the moisture collector 1000 via one or more outlets. For example, as shown in fig. 10A, a gas flow 1009 may enter the moisture collector 1000 via the inlet 1008, and the gas flow may be separated into a first gas flow 1014 and a second gas flow 1016 exiting the moisture collector 1000 via the first outlet 1010 and the second outlet 1012, respectively.

In some embodiments, moisture collector 1000 includes cup 1002, cover 1004, and moisture filter 1006. In some embodiments, a moisture filter 1006 is disposed between the cup 1002 and the cover 1004. The gas flow 1009 may flow from the inlet 1008 through the moisture filter 1006 and out the outlet 1010 and/or the outlet 1012. Moisture filter 1006 may be permeable to gas but impermeable to moisture (such as water droplets or water vapor). For example, the moisture filter 1006 may include a material having pores configured to allow gas molecules to pass through but not larger particles (such as water molecules or solid particles). In some embodiments, the moisture filter 1006 includes a porous membrane. In some embodiments, the porous membrane is a gas permeable membrane. In some embodiments, the porous membrane is a hydrophobic membrane.

In some embodiments, moisture collector 1000 includes one or more flow paths configured to allow a flow of gas from an inlet to an outlet. In some embodiments, moisture collector 1000 includes a first chamber 1018 and a second chamber 1020 defining a flow path. The first chamber 1018 may be disposed downstream of and in fluid communication with the inlet 1008. A second chamber 1020 may be disposed downstream of and in fluid communication with the first chamber 1018 and upstream of and in fluid communication with the outlet 1010. The moisture filter 1006 may be disposed between the first chamber 1018 and the second chamber 1020. The gas flow 1009 may flow from the first chamber 1018 through the moisture filter 1006 to the second chamber 1020, and the gas flow may become a first gas flow 1014 having a lower moisture level than the gas flow 1009.

For example, moisture blocked by the moisture filter 1006 may accumulate in the first chamber 1018 and on the moisture filter 1006. The accumulated moisture may form liquid droplets. Liquid droplets may accumulate on a side of the moisture filter 1006 facing the gas flow 1009 or the first chamber 1018, may be collected in the first chamber 1018, and may flow to the cup 1002 through the opening 1022 of the first chamber 1018. Liquid that accumulates on the moisture filter 1006 may reduce the throughput of the gas flow 1009 through the moisture filter, such as liquid that accumulates on the side of the moisture filter 1006 facing the first chamber 1018. Such liquid accumulation may clog the pores of the gas permeable membrane of the moisture filter 1006 and reduce the gas throughput of the moisture collector 1000. In some embodiments, the moisture filter 1006 is disposed at an oblique angle to facilitate accumulation of liquid due to gravity toward the edges of the moisture filter 1006.

In some embodiments, moisture collector 1000 includes one or more additional flow paths to increase the throughput of gas flow through moisture collector 1000. For example, the moisture filter 1006 may include a third chamber 1024 and a fourth chamber 1026. The third chamber 1024 may be disposed in fluid communication with the cup 1002, such as via an opening. A fourth chamber 1026 may be disposed downstream of and in fluid communication with the third chamber 1024, and the fourth chamber is disposed upstream of and in fluid communication with the outlet 1012. The moisture filter 1006 may be disposed between the third chamber 1024 and the fourth chamber 1026. As shown in fig. 10A, a second gas flow 1016 may be directed toward cup 1002 by moisture filter 1006, and may flow from cup 1002 to third chamber 1024, through moisture filter 1006, and to fourth chamber 1026. The second gas stream 1016 may exit the moisture collector 1000 via an outlet 1012. The second gas stream 1016 may sweep away liquid (e.g., water) that has accumulated on the moisture filter 1006, thereby increasing the throughput of gas through the moisture filter 1006.

In some embodiments, as shown in fig. 11A-11D, one or more outlets of the moisture collector 1000 are in fluid communication with a gas sensing circuit of the gas monitoring apparatus 1100. For example, outlets 1010 and 1012 may be in fluid communication with a gas sensing circuit. One or more gas streams from the moisture collector 1000 may be used to measure gas concentration through a gas sensing loop. In some embodiments, the first gas flow 1014 from the moisture collector 1000 is used by the gas sensing loop to measure gas concentration.

The gas sensing circuit of the gas monitoring apparatus 1100 may include various components and features for measuring gas concentration and/or improving measurement accuracy. In some embodiments, the gas monitoring apparatus 1100 includes a sensing module 1102. The sensing module 1102 may include one or more gas sensors, such as NO ₂ Sensor 1102a, NO sensor 1102b and O ₂ A sensor 1102c. The one or more gas sensors may be disposed in one or more chambers configured to receive at least a portion of a gas flow (such as first gas flow 1014) circulating in the gas sensing circuit. For example, as shown in fig. 11A-11D, a gas sensor may be provided in one chamber to measure the gas concentration of the gas flowing therethrough. The gas monitoring device 1100 may include a computer readable storage device and/or a processor (not shown) in wired or wireless communication with the sensor to receive and process the sensing signals received from the sensor. Gas monitoring device 1100 may include a transmitter loop (not shown) in wired or wireless communication with a processor, computer readable storage device, and/or gas sensor to transmit a sensed signal or reading to a controller, such as control 918 or an electronic device (e.g., a tablet, computer, or smart phone). The readings of the gas sensor may be obtained by the gas sensor or the processor based on the sensed signals.

In some embodiments, the gas sensing circuit of the gas monitoring apparatus 1100 includes a pump 1104. The pump 1104 is configured to generate or drive one or more gas streams in the gas sensing circuit. In some embodiments, the gas sensing circuit includes one or more valves configured to direct one or more gas flows in the gas sensing circuit. For example, the gas sensing circuit may include at least one-way valve 1106, such as a ball check valve. The check valve 1106 may be provided in any suitable location to prevent backflow. For example, the pump 1104 may be disposed at a location downstream of the gas sensing circuit such that the flow of gas from the pump outlet may be released into the environment. A check valve 1106 may be provided downstream of pump 1104 to prevent backflow of ambient air into the gas sensing circuit.

In some embodiments, the gas monitoring apparatus 1100 includes one or more switching valves configured to change the direction or flow path of the gas flow in the gas sensing circuit. For example, the gas monitoring apparatus 1100 may include a first switching valve 1110 and a second switching valve 1112. The switching valve may have one or more positions (such as a first position and a second position) for selecting a gas flow path or direction in the gas sensing circuit. The position of the switching valve may be selected manually or automatically using a user interface. The user interface may be, for example, a graphical user interface or a control panel, such as a switch or button.

In some embodiments, one or more switching valves may be provided in the control module 1114. As shown in fig. 11A-11D, the control module 1114 may include one or more connection ports, such as connection ports 1116A-1116G. The switching valve may be fluidly connected to one or more connection ports. Such a configuration may improve the assemblability and/or maintainability of the gas monitoring apparatus 1100. For example, the first switching valve 1110 may have a first position to fluidly connect the connection ports 1116A and 1116C and the first switching valve may have a second position to fluidly connect the connection ports 1116A and 1116D. For example, the second switch valve 1112 may have a first position to fluidly connect the connection ports 1116E and 1116G, and the second switch valve may have a second position to fluidly connect the connection ports 1116F and 1116G. In some embodiments, the selected connection ports may be fluidly connected to form one or more flow paths. For example, connection ports 1116B and 1116C may be fluidly connected. Various uses of the switching valve during one or more operations of the gas monitoring apparatus 1100 are further described below.

In some embodiments, the gas monitoring apparatus 1100 includes one or more pressure sensors. In some embodiments, the gas monitoring apparatus 1100 includes at least one absolute pressure sensor 1118. In some embodiments, the gas monitoring apparatus 1100 includes at least one differential pressure sensor 1120. The differential pressure sensor may be used to measure the flow rate of the gas flow in the gas sensing circuit. For example, the flow rate of the gas flow may be calculated based on the differential pressure measured by differential pressure sensor 1120 and the Bernoulli equation.

In some embodiments, the gas sensing circuit of the gas monitoring apparatus 1100 includes one or more flow regulators, such as a first flow regulator 1122 and a second flow regulator 1124. The flow regulator may be a flow controller, a flow restrictor or a flow restrictor. The flow regulator may be configured to control the flow of the gas stream therethrough. For example, the flow regulator may be configured to limit the flow of the gas stream of the flow path to a particular range or value. In some embodiments, the first flow regulator 1122 is configured to regulate the first gas flow 1014 from the moisture collector 1000. In some embodiments, the second flow regulator 1124 is configured to regulate the second gas flow 1016 from the moisture collector 1000. In some embodiments, differential pressure sensor 1120 is configured to measure a differential pressure across flow regulator 1122.

In some embodiments, the gas monitoring apparatus 1100 includes one or more filters. The filter may be disposed at any suitable location in the gas sensing circuit to reduce or remove one or more impurities in the gas stream, such as moisture and solid matter. Such a filter may further reduce or remove moisture in the gas sensing module to improve the measurement accuracy of the gas sensor. Additionally or alternatively, such a filter may reduce or prevent solid matter from entering the valve, which may increase the life of the gas monitoring apparatus 1100.

In some embodiments, the filter 1128 is disposed upstream of the gas sensing module 1102. The filter 1128 may include a moisture filter configured to reduce or remove moisture, such as water, in the gas and/or liquid phases. The filter 1128 may comprise a membrane filter, such as Nafion ^TM A membrane filter. The gas sensing circuit of the gas monitoring apparatus 1100 may include one or more gas inlets (such as a first gas inlet 1127a and a second gas inlet 1127 b) configured to receive an air flow from an ambient or gas supply (such as a compressed air supply). A filter 1126 may be provided downstream of the gas inlet to reduce or remove moisture and/or dust from the gas stream received by the gas inlet.

In some embodiments, the gas sensing circuit includes one or more NO _x Absorber 1108.NO (NO) _x The absorber 1108 may be configured to absorb one or more oxides of nitrogen, such as NO ₂ And NO. In some embodiments, NO _x An absorber 1108 is disposed upstream of the gas inlet to remove or reduce one or more nitrogen oxides, such as NO, in the air stream entering the gas sensing circuit via the gas inlet ₂ And NO. The gas sensing circuit can include one or more gas outlets (such as gas outlet 1129) configured to output a gas stream (such as second gas stream 1016 or first gas stream 1014) into the environment. In some embodiments, NO _x An absorber 1108 is provided downstream of the gas outlet to remove or reduce the gas flow prior to release into the environmentAt least one or more nitrogen oxides, e.g. NO ₂ And NO.

NO _x The absorber 1108 may include a catalyst configured to absorb one or more oxides of nitrogen NO _x (e.g. NO and NO ₂ ) Is a material that is absorbent. NO (NO) _x The absorbent material in the absorber 1108 may be similar to the absorbent material of the exhaust treatment device 700. NO (NO) _x The absorber 1108 may have a structure similar to that of the exhaust treatment device 700. For example, NO _x The absorber 1108 may include a tortuous flow path, at least a portion of which is filled with one or more absorbent materials.

The various components of the gas monitoring apparatus 1100 may be used in one or more operational processes, such as an initialization process, a calibration process, a sampling process, and a cleaning process. Such one or more operational processes may be automatically controlled by the processor and/or manually controlled by a user via a user interface (such as a control panel or graphical user interface). Embodiments of various processes performed by the gas monitoring apparatus 1100 are described below.

In some embodiments, the gas monitoring apparatus 1100 is configured to perform an initialization process. Fig. 11A is a schematic diagram of a process for 1000 a gas monitoring apparatus according to some embodiments of the present disclosure. An initialization process may be performed to reduce or remove moisture in the gas sensing circuit and/or purge pre-existing gas from the gas sensing circuit. For example, during an initialization process, ambient air may be introduced into and through at least a portion of the gas sensing circuit to dry and/or purge one or more flow paths of the sensing module 1102 and/or the gas sensing circuit.

In some embodiments, as shown in fig. 11A, one or more switching valves may be switched into position to fluidly connect selected connection ports during an initialization process to direct one or more gas flows in a gas sensing circuit. For example, the first switching valve 1110 may be switched to a second position to fluidly connect the connection ports 1116A and 1116D. The second switching valve 1 can be112 to their second position to fluidly connect connection ports 1116F and 1116G. As indicated by the arrows in fig. 11A, during an initialization process, for example, pump 1104 may generate an air flow through the gas sensing circuit (i.e., from gas inlet 1127a, through connection ports 1116D and 1116A, sensing module 1102, filter 1128, connection ports 1116G and 1116F, to outlet 1010). During the initialization process, air flow may also flow through one or more of the flow regulator 1122, the filter 1126, the flow regulator 1124, and the check valve 1106. The air flow may flow through NO before exiting the sensing loop via gas outlet 1129 _x Absorber 1108.

During the initialization process, as shown in fig. 11A, pump 1104 may drive an air flow to outlet 1010, through cup 1002, outlet 1012, connection ports 1116B and 1116C, and to gas outlet 1129. The initialization process may be performed for any suitable duration, such as less than about 1 minute, less than about 30 seconds, less than about 10 seconds, or less than about 1 second.

During the initialization process, it may be determined whether various components of the gas monitoring apparatus 1100 may operate under normal conditions. Additionally or alternatively, the gas monitoring apparatus 1100 may generate one or more alarms, indicating one or more abnormal conditions of the gas sensing circuit. For example, the switching valve may be switched to a different position to determine whether the valve may operate under normal conditions. The pump 1104 may be set to a certain flow rate and the flow rate of the gas stream generated by the pump 1104 may be measured to determine whether the pump 1104 may operate under normal conditions. When there is no gas flow in the gas sensing circuit, the normal reading of absolute pressure sensor 1118 may not exceed a predetermined value, such as any value from about 600mbar to about 1250mbar, and the calculated normal flow based on the reading of differential pressure sensor 1120 may not exceed a flow range predetermined by the pump setting, such as from about 50ml/min to about 1000ml/min.

In some embodiments, the gas monitoring apparatus 1100 is configured to perform a calibration process to calibrate one or more gas sensors in the sensing module 1102. The calibration procedure may be performed regularly,such as periodically, on demand, or prior to delivering the gas mixture 907 to the patient. The sensor may be calibrated using standard gas of known concentration of air (such as ambient air or compressed air) or its gaseous components. Fig. 11B is a schematic diagram of a calibration process of a gas monitoring apparatus 1100 according to some embodiments of the present disclosure. In some embodiments, as shown in fig. 11B, ambient air is used in the calibration process. For example, the first switching valve 1110 may be switched to its first position to fluidly connect the connection ports 1116B and 1116C. The second switch valve 1112 may be switched to its first position to fluidly connect the connection ports 1116E and 1116G. The pump 1104 may generate an air flow from the gas inlet 1127b through the connection ports 1116E and 1116G, the filter 1128, the sensing module 1102, the connection port 1116A, and the connection port 1116C to the gas outlet 1129. NO (NO) _x An absorber 1108 may be provided downstream of the gas inlet 1127b to remove or reduce NO prior to the air flow passing through the sensing module 1102 ₂ And NO. The air flow may also pass through one or more of the flow regulator 1122, the filter 1126, and the one-way valve 1106.

During the calibration process, pump 1114 may also drive gas flow 1016 from outlet 1012 to gas outlet 1129 through connection ports 1116B and 1116C. The gas stream 1016 may also flow through a filter 1126, a flow regulator 1124, a check valve 1106, and NO _x One or more of the absorbers 1108.

In some embodiments, a calibration process is performed to adjust a calibration curve of at least one sensor of the sensing module 1102, such as adjusting the calibration curve with an offset value. The calibration process may include zero calibration and/or span calibration. For example, in zero calibration, air flow from the environment is passing through NO _x Absorber 1108 may then be predetermined to have approximately 21% O ₂ About 0% or 0ppm NO and about 0% or 0ppm NO ₂ . The sensor of the sensing module may assume that the readings of the air flow correspond to these predetermined concentrations and may adjust their calibration curves with offset values.

In some embodiments, in span calibration, the calibration process may be performedWith O ₂ NO and/or NO ₂ Is known to the person skilled in the art. As shown in fig. 11C, the first switching valve 1110 may be switched to its first position to fluidly connect the connection ports 1116A and 1116C. The second switch valve 1112 may be switched to its second position to fluidly connect the connection ports 1116F and 1116G. The pump 1104 may drive the standard gas from the outlet 1010 through the connection ports 1116F, 1116G, filters 1128, the sensing module 1102, 1116A and 1116C and to the gas outlet 1129. The standard gas flow may also pass through the flow regulator 1122, the one-way valve 1106, and NO before being released through the gas outlet 1129 _x One or more of the absorbers 1108. The sensor of the sensing module may assume that the reading of the standard gas flow corresponds to a known concentration of the standard gas and may adjust their calibration curve with an offset value.

In some embodiments, the gas monitoring apparatus 1100 is configured to perform a sampling process to measure the concentration of one or more gas components in a sample gas stream. Fig. 11C is a schematic diagram of a sampling process of a gas monitoring apparatus 1100 according to some embodiments of the present disclosure. The sampling process may be performed on an as-needed basis, or may be performed continuously or intermittently while the gas mixture 907 is being delivered to the patient 910. In some embodiments, during sampling, the gas sensing circuit may receive a first gas flow 1014 from an outlet 1010 of the moisture collector 1000 and/or may receive a second gas flow 1016 from an outlet 1012 of the moisture collector 1000. The first flow regulator 1122 can regulate the flow of the first gas stream 1014 to a first flow. The second flow regulator 1124 can regulate the flow of the second gas stream 1016 to a second flow. The first and second flows may be predetermined and adjusted based on the settings of the pump 1104 and/or the settings of the flow regulators 1122 and 1124. The first flow and the second flow may add up to the flow of the pump 1104. For example, the flow rate of the pump 1104 may be in the range of about 50mL/min to about 1000mL/min, the first flow rate of the first gas flow 1014 may be in the range of about 40mL/min to about 800mL/min, and the second flow rate of the second gas flow 1016 may be in the range of about 10mL/min to about 200 mL/min.

In some embodiments, the concentration in the first gas stream 1014 is measured during sampling. As shown in fig. 11C, the first switching valve 1110 may be switched to its first position to fluidly connect the connection ports 1116A and 1116C. The second switch valve 1112 may be switched to its second position to fluidly connect the connection ports 1116F and 1116G. The pump 1104 may drive the first gas flow 1014 from the outlet 1010 through the connection ports 1116F, 1116G, the filter 1128, the sensing module 1102, 1116A, and 1116C and to the gas outlet 1129. The first gas stream 1014 may also pass through the flow regulator 1122, the one-way valve 1106, and NO before being released through the gas outlet 1129 _x One or more of the absorbers 1108. The pump 1104 may also drive the second gas stream 1016 from the outlet 1012 to the gas outlet 1129 through the connection ports 1116B and 1116C. The second gas stream 1016 may also pass through the flow regulator 1124, the one-way valve 1106, and NO before being released via the gas outlet 1129 _x One or more of the absorbers 1108.

In some embodiments, the one or more gas sensors of the sensing module 1102 are configured to identify and measure one or more gas components (such as NO ₂ NO and O ₂ ) Is a concentration of (3). Readings from these sensors may be transmitted by wired or wireless communication to a processor and/or computer readable storage medium (not shown) of the gas monitoring apparatus 1100 for further processing and/or transmission to one or more other apparatuses.

The accuracy of one or more sensors in the sensing module 1102 may be improved when the first gas flow 1014 passes the sensors at or within a predetermined flow rate. In some embodiments, the flow of the first gas stream 1014 is regulated by a flow regulator 1122, and a differential pressure sensor 1120 is used to measure the flow of the first gas stream 1014 through the flow regulator 1122. The predetermined flow rate or flow rate range may be any suitable value or range based on the type of sensor. For example, the one or more sensors may be electrochemical sensors, and the predetermined flow rate may range from about 50ml/min to about 450ml/min, such as from about 220ml/min to about 240ml/min. The pump 1104 may be used to adjust the flow of the first gas stream 1014 through the sensing module to a predetermined value or range.

In some embodiments, the gas monitoring apparatus 1100 is configured to perform a cleaning process to reduce or remove liquid that accumulates on the moisture filter 1006 of the moisture collector 1000 and/or in the gas sensing circuit. Fig. 11D is a schematic diagram of a cleaning process of a gas monitoring apparatus 1100 according to some embodiments of the present disclosure. As shown in fig. 11D, the first switching valve 1110 may be switched to its second position to disconnect the ports 1116A and 1116C, thereby disconnecting the first gas flow 1014. The second switch valve 1112 may be switched to its first position to fluidly connect the connection ports 1116E and 1116G. The pump 1104 may drive the second gas stream 1016 from the outlet 1012 through connection port 1116B and connection port 1116C and to the gas outlet 1129. The second gas stream 1016 may also pass through a filter 1126, a flow regulator 1124, a one-way valve 1106, and NO before being released via a gas outlet 1129 _x One or more of the absorbers 1108.

During the cleaning process, the disconnection of the first gas flow 1014 allows the flow rate of the second gas flow 1016 to be increased. As shown in fig. 10A, prior to exiting the outlet 1012, a second gas stream 1016 may flow from the first chamber 1018 to the cup 1002 and back to the moisture filter 1006, such as the side of the moisture filter 1006 facing the gas stream 1009 or the side facing the first chamber 1018 where liquid may accumulate. Increasing the flow of the second gas stream 1016 may increase the drying or sweeping of the liquid accumulated on the moisture filter 1006.

The gas monitoring apparatus 1100 may perform a cleaning process on an as-needed basis and/or upon the occurrence of one or more abnormal conditions. The cleaning process may be performed for any suitable duration, such as less than about 2 minutes, less than about 1 minute, less than about 30 seconds, or less than about 10 seconds. The cleaning process may be started automatically or manually. For example, when the liquid blocks at least a portion of the moisture filter 1006 and/or the flow path in the gas sensing circuit, the processor of the gas monitoring apparatus 1100 may begin the cleaning process in response to one or more abnormal readings of the absolute pressure sensor 1118 and/or the differential pressure sensor 1120. For example, during the sampling process, the normal absolute pressure measured by pressure sensor 1118 may be in the range of about 0.5bar to about 1.25 bar. Absolute pressures outside of this range may indicate that the moisture filter 1006 and/or the gas sensing circuit is blocked by liquid. The normal flow calculated based on the differential pressure measured by pressure sensor 1120 may range from about 20ml/min to about 275ml/min, such as from about 20ml/min to about 50ml/min, from about 50ml/min to about 100ml/min, from about 100ml/min to about 150ml/min, from about 150ml/min to about 200ml/min, from about 200ml/min to about 250ml/min, or from about 250ml/min to about 275ml/min. Flow rates below this range may indicate that the moisture filter 1006 and/or gas sensing circuit is clogged with liquid.

As described herein, the system 10 may be modular such that one or more components thereof, such as the reaction chamber 102, the reaction medium 112, one or more electrodes (e.g., the first electrode 116, the second electrode 118), the filtration system 500 or filters thereof, the pressure vessel 600, the exhaust treatment device 700, the gas converter 800, and the flow control device may be conveniently replaced, serviced, or repaired without substantial disassembly of the system 10. Accordingly, maintenance costs of the system 10 may be reduced and the operational life of the system 10 may be extended.

In some embodiments, the system 10 may include a user interface in communication with the control loop. The user interface may comprise one or more controllers for receiving instructions from a user to adjust system parameters such as the number of phases, the number of operating cycles in each phase, the concentration and/or flow of NO in the phase or operating cycle. The control loop may send control signals to various components to adjust these system parameters, such as the energy source 114, the carrier gas source 200, and a flow controller or control device.

The system 10, or one or more components thereof, such as the NO generation apparatus 100 described herein, may be used in various methods for generating and/or delivering NO. For example, the system 10 or the NO generating device 100 may be used to generate NO on demand. In some embodiments, the system 10 or the NO generating device 100 may be used to provide a steady NO supply at a predetermined concentration during a ramp period. The ramp period may refer to a transition period during which the NO concentration of the product gas may vary from an initial concentration to a predetermined steady state concentration. For example, during a ramp period, the NO concentration of the product gas increases from an initial concentration (e.g., zero) to a predetermined steady-state concentration. The system 10 or the NO generating device 100 may be used to provide a stable NO supply during one or more phases or during one or more operating cycles. The system 10 may be used to reduce or minimize potential air pollution and/or exposure to toxic gases (such as nitrogen dioxide) during NO generation or delivery. The system 10 may be used to deliver NO using another process gas (such as oxygen or air) supplied by a respiratory device (such as a ventilator). The system 10 may be used to monitor the concentration of one or more components of a gas mixture to be delivered to or inhaled by a patient.

As described herein, the steps of the disclosed methods may be modified in any manner, including reordering steps, inserting steps, and/or deleting steps. Unless otherwise indicated, one or more steps of the disclosed methods may be performed concurrently or in any suitable order of time.

Fig. 12 is a flow chart illustrating a NO generation method 1200 according to some embodiments of the present disclosure. In some embodiments, as shown in FIG. 12, method 1200 includes steps 1202-1210. In some embodiments, step 1202 includes applying a voltage or current to one or more of a plurality of electrodes disposed in the reaction medium by an energy source to generate NO. The plurality of electrodes may include a cathode. In some embodiments, NO is generated at or near one or more surfaces of the plurality of electrodes. The reaction medium may be contained in a reaction chamber of the NO generating device. In some embodiments, the reaction chamber includes a gas region and a liquid region, and the reaction medium is disposed in the liquid region.

In some embodiments, in step 1202, the voltage or current applied to the plurality of electrodes may be predetermined and/or adjusted based on one or more conditions, such as a desired concentration of NO in the output product gas. In some embodiments, the predetermined voltage ranges from about 1.4V to about 5.0V. In some embodiments, the predetermined current ranges from about 0mA to about 300mA. The rate of NO generation may increase with increasing voltage or current applied to the plurality of electrodes. In some cases, NO may be generated when a current of about 0mA is applied to the plurality of electrodes. In some embodiments, step 1202 includes terminating the voltage or current applied to the plurality of electrodes.

In some embodiments, step 1202 includes applying an excitation voltage or excitation current to the plurality of electrodes for an excitation period prior to applying the predetermined voltage or predetermined current. The excitation period may range from about 0.5 minutes to about 5 minutes, such as from about 0.5 minutes to about 1 minute, from about 1 minute to about 2 minutes, from about 2 minutes to about 3 minutes, from about 3 minutes to about 4 minutes, from about 4 minutes to about 5 minutes, or a combination thereof. In some embodiments, the excitation voltage is about 2 to about 8 times the predetermined voltage. In some embodiments, the excitation current is about 2 to about 8 times the predetermined current.

In some embodiments, step 1202 includes switching the polarity of the two electrodes (e.g., cathode and anode). For example, step 1202 may include reversing the polarity of the energy source, such as reversing the polarity of a DC power source or by using an AC power source. The polarity of the two electrodes may be switched on demand or according to a predetermined schedule. For example, the polarity of the two electrodes may be switched periodically, such as from about every 10 minutes to about every 10 hours.

In some embodiments, method 1200 includes step 1204. In some embodiments, step 1204 includes receiving, by the NO generating device, a carrier gas through an inlet loop of the NO generating device. The inlet circuit may be in fluid communication with at least one sparger disposed in the reaction medium. The at least one sprayer may be located adjacent to one or more of the plurality of electrodes. In some embodiments, the carrier gas is received from a carrier gas source. In some embodiments, the carrier gas comprises nitrogen. In some embodiments, step 1204 includes generating carrier gas from the compressed air by a carrier gas source. For example, a nitrogen generating device may be used to generate the carrier gas from compressed air.

In some embodiments, step 1204 includes controlling, by a flow control device, a flow of carrier gas received through the inlet circuit. In some embodiments, step 1204 includes receiving the carrier gas at a flow rate ranging from about 50mL/min to about 12L/min, such as from about 0.5L/min to about 1L/min, from about 1L/min to about 3L/min, from about 3L/min to about 5L/min, from about 5L/min to about 8L/min, from about 8L/min to about 10L/min, from about 10L/min to about 12L/min, or a combination thereof.

In some embodiments, step 1204 includes purging system 10 with a carrier gas. For example, the carrier gas may pass through some or all of the gas flow regions or paths of the system, such as the gas regions, inlet and outlet circuits, circulation circuits, and pressure vessels of the reaction chamber. Oxidation of NO generated in the product gas to toxic nitrous oxides (e.g., NO) may be reduced by the carrier gas purging system 10 ₂ ). Purging the system 10 may increase the life of a gas converter configured to reduce or remove NO ₂ 。

In some embodiments, method 1200 includes step 1206. In some embodiments, step 1206 comprises sweeping a surface of one or more of the plurality of electrodes with a carrier gas. Sweeping the surface of the electrode may sweep, and/or entrain NO generated at or near the surface of the electrode from the reaction medium. This may generate a product gas, which may include the generated NO and carrier gas. In some embodiments, at least a portion of the product gas is received and/or accumulated in a gas region of a reaction chamber of the NO generating device.

In some embodiments, step 1206 includes generating bubbles of a carrier gas to sweep a surface of one or more of the plurality of electrodes. For example, step 1206 may include receiving a carrier gas by a sparger, and the step may include emitting bubbles of the carrier gas in a reaction medium by the sparger to sweep a surface of one or more of the plurality of electrodes. A sparger can be in fluid communication with the inlet circuit and the sparger disposed in the reaction medium adjacent one or more of the plurality of electrodes. The bubbles emitted by the sparger may propagate along a bubble path that may extend along the surface of at least one electrode.

In some embodiments, method 1200 includes step 1208. In some embodiments, step 1208 includes circulating the first fluid stream relative to the reaction chamber using a first circulation loop. In some embodiments, step 1208 includes generating, by a gas pump, a first fluid flow from an inlet to an outlet of the first circulation loop. In some embodiments, the first fluid stream comprises the product gas stream generated in step 1206. In some embodiments, step 1208 includes filtering the recirculated fluid flow using one or more filters disposed upstream of the gas pump. The one or more filters may reduce or remove liquid and/or solid matter in the recycled fluid stream before the recycled fluid stream enters the gas pump.

In some embodiments, step 1208 may include circulating the first fluid flow at a flow rate ranging from about 0.5L/min to about 5.0L/min, such as from about 0.5L/min to about 1.0L/min, from about 1.0L/min to about 1.5L/min, from about 1.5L/min to about 2.0L/min, from about 2.0L/min to about 2.5L/min, from about 2.5L/min to about 3.0L/min, from about 3.0L/min to about 3.5L/min, from about 3.5L/min to about 4.0L/min, from about 4.0L/min to about 4.5L/min, from about 4.5L/min to about 5.0L/min, or a combination thereof.

In some embodiments, method 1200 includes step 1210. In some embodiments, step 1210 includes delivering a NO-containing product gas from the reaction chamber through an outlet loop. In some embodiments, the outlet circuit is in fluid communication with the gas region of the reaction chamber. In some embodiments, the NO concentration of the product gas delivered from the reaction chamber may reach steady state during the ramp period. For example, the ramp period may range from about 2 minutes to about 10 minutes.

In some embodiments, method 1200 may include one or more steps selected from steps 1212-1222 described below.

In some embodiments, method 1200 includes step 1212. In some embodiments, step 1212 includes measuring the concentration of NO in the product gas using a NO concentration sensor. In some embodiments, a NO concentration sensor may be disposed in contact with the product gas in the gas region to measure the NO concentration in the gas region. In some embodiments, a NO concentration sensor may be disposed in, near, or downstream of the outlet circuit of the reaction chamber to detect the NO concentration of the product gas exiting the reaction chamber. For example, the NO sensor may be provided at the opening of the outlet circuit, within the conduit of the outlet circuit or downstream of a filter provided downstream of the outlet circuit.

In some embodiments, method 1200 includes step 1214. Step 1214 may reduce or remove NO dissolved in the reaction medium after NO is generated during the phase or operation period. Step 1214 may include separating at least some of the dissolved NO from the reaction medium. Step 1214 may further include treating the separated NO, such as with an exhaust treatment device.

In some embodiments, step 1214 includes circulating the second fluid flow relative to the reaction chamber using a second circulation loop. In some embodiments, the second fluid flow in the second circulation loop comprises a liquid flow. In some embodiments, the second fluid flow in the second circulation loop comprises a gas flow. In some embodiments, step 1214 is performed before, during, and/or after generating NO using the reaction medium in step 1202. For example, step 1214 may be performed after terminating the voltage or current applied to the electrode after generating NO during the phase or period of operation. Step 1214 may be performed prior to beginning application of a voltage or current to the electrode to generate NO for the next phase or cycle of operation.

In some embodiments, step 1214 includes configuring and/or operating the second recirculation loop to operate in a working mode. In the operating mode, the second fluid stream may comprise a reaction medium stream. In some embodiments, operating the second circulation loop in the operational mode includes circulating a second fluid flow from a first port of the second circulation loop through the liquid-gas separation device and out a second port of the second circulation loop using a pump. The first port may be in fluid communication with a liquid region of the reaction chamber and the second port may be in fluid communication with a gas region of the reaction chamber.

In the operational mode, the second fluid flow may be circulated at any suitable flow rate, such as a flow rate ranging from about 0.1L/min to about 0.5L/min, from about 0.5L/min to about 1.0L/min, from about 1.0L/min to about 3.0L/min, from about 3.0L/min to about 5.0L/min, from about 5.0L/min to about 8.0L/min, or a combination thereof. The second circulation loop may be operated in the operational mode for any suitable time, such as less than about 0.5 minutes, less than about 1 minute, less than about 2 minutes, less than about 5 minutes, less than about 10 minutes, or less than about 20 minutes.

In some embodiments, operating the second circulation loop in the operating mode includes separating NO from the reaction medium as the second fluid stream passes through the liquid-gas separation device. In some embodiments, operating the second circulation loop in the operating mode includes passing a sweep gas through the liquid-gas separation device to entrain NO separated from the second fluid stream as a mixed gas from the liquid-gas separation device. In some embodiments, operating the second recirculation loop in the operational mode includes delivering the mixed gas to an exhaust gas treatment device prior to releasing the mixed gas into the environment.

In some embodiments, step 1214 includes configuring and/or operating the second recirculation loop in the cleaning mode. The cleaning mode may be operated after the operating mode. In the cleaning mode, the second fluid flow may comprise a gas flow. In some embodiments, operating the second circulation loop in the cleaning mode includes circulating a second fluid flow from the second port of the second circulation loop through the liquid-gas separation device and out of the first port of the second circulation loop using a pump. In some embodiments, operating the second circulation loop in the cleaning mode includes transporting residual reaction medium in the liquid-gas separation device back to the reaction chamber. The cleaning mode may prepare the liquid-gas separation device for the next operation mode, such as by drying the separation membrane of the liquid-gas separation device.

In the cleaning mode, the second fluid flow may be circulated at any suitable flow rate, such as a flow rate ranging from about 0.25L/min to about 0.5L/min, from about 0.5L/min to about 1.0L/min, from about 1.0L/min to about 3.0L/min, from about 3.0L/min to about 5.0L/min, or a combination thereof. The second circulation loop may be operated in the cleaning mode for any suitable time, such as less than about 0.5 minutes, less than about 1 minute, less than about 2 minutes, or less than about 5 minutes.

In some embodiments, step 1214 may include configuring the switching valve to a first position to allow the second circulation loop to operate in the operational mode, and step may include configuring the switching valve to a second position to allow the second circulation loop to operate in the cleaning mode.

In some embodiments, step 1214 includes purging the reaction chamber (e.g., the gas region of the reaction chamber) with a carrier gas. The carrier gas may accumulate in the gas region of the reaction chamber and the carrier gas may circulate in the second circulation loop in the cleaning mode.

In some embodiments, method 1200 includes step 1216. In some embodiments, step 1216 includes passing the product gas from the reaction chamber through a filtration system. Step 1216 may include reducing or removing, by a filtration system, one or more impurities in the product gas, such as solid matter (e.g., salt aerosols) and moisture. The filtration system may include one or more filtration devices or filters.

In some embodiments, method 1200 includes step 1218. In some embodiments, step 1218 comprises delivering the product gas to a pressure vessel. In some embodiments, step 1218 includes receiving and storing the product gas in a pressure vessel for a pressure maintenance time. At the end of the pressure maintenance period, the pressure and/or NO concentration in the pressure vessel may be increased to a predetermined level or predetermined range. In some embodiments, the pressure vessel includes a first region and a second region. Step 1218 may include receiving a product gas through an inlet in fluid communication with the first region of the pressure vessel. Step 1218 may include storing the product gas in a first region of a pressure vessel. Step 1218 may include releasing the product gas from the pressure vessel, such as through an outlet in fluid communication with the first zone. The concentration of NO in the product gas released from the pressure vessel may reach steady state during the ramp cycle. The ramp period may refer to a transition period during which the NO concentration of the product gas may vary from an initial concentration to a predetermined steady state concentration. In some embodiments, step 1218 includes measuring and/or adjusting the flow of product gas released from the pressure vessel using a flow control device. The flow control device may adjust the flow rate of the product gas in accordance with instructions received from the control device.

In some embodiments, step 1218 includes receiving and storing the product gas in a second zone in fluid communication with the first zone. Step 1218 may include storing the product gas in the second zone at a pressure less than or equal to a predetermined threshold. Step 1218 may include releasing the product gas stored in the second region from the second region to the first region, and the step may further include releasing the product gas from the first region out of the pressure vessel. In some embodiments, step 1218 includes releasing gas from the pressure vessel (e.g., from a second region of the pressure vessel) through a pressure release valve when the pressure in one or more regions of the pressure vessel exceeds a predetermined threshold. In some embodiments, step 1218 includes treating the gas released through the pressure relief valve, for example, by an exhaust treatment device.

In some embodiments, method 1200 includes step 1220. In some embodiments, step 1220 may include transporting the product gas through a gas converter to reduce or remove one or more toxic nitrogen oxides, such as NO, in the product gas ₂ . In some embodiments, step 1220 includes absorbing or converting some or all of the toxic nitrogen oxides, such as NO, by the gas converter as the product gas passes through ₂ . Toxic and poisonousCan be converted into NO. Step 1220 may include passing the product gas from the inlet through a tortuous flow path to the outlet of the gas transducer, and may include passing the product gas through a filter material in the tortuous flow path. Step 1220 may include absorbing some or all of the toxic nitrogen oxides in the product gas using a filter material. Additionally or alternatively, step 1220 may include converting some or all of the toxic nitrogen oxides in the product gas to NO using a filter material.

In some embodiments, method 1200 includes step 1222. In some embodiments, step 1222 includes delivering NO or a gas mixture including NO to the patient using a ventilation circuit. The gas mixture may include one or more gas components such as air, oxygen, moisture. In some embodiments, step 1222 includes delivering NO or a gas mixture to the patient through an inspiratory circuit of the ventilation circuit. In some embodiments, step 1222 includes receiving exhaled gas from the patient through an exhalation circuit of the ventilation circuit.

In some embodiments, step 1222 includes delivering NO via a flow of gas (such as an air flow or an oxygen flow) supplied by a respiratory device (such as a ventilator) connected to the ventilation circuit. For example, step 1222 may include combining a flow of gas (such as a flow of air or oxygen) supplied by a respiratory device (such as a ventilator) with a flow of product gas received from the NO system to generate a gas mixture. In some embodiments, step 1222 includes adding the aqueous split mixture prior to delivering the gas mixture to the patient.

In some embodiments, step 1222 includes measuring a flow of gas (such as an air flow or an oxygen flow) supplied from a respiratory device (such as a ventilator) using a flow sensor. The flow sensor may communicate with the control device via a wired connection or a wireless connection. Step 1222 may further include transmitting a sensing signal or reading from the flow sensor to the control device.

In some embodiments, step 1222 includes measuring, by one or more gas sensors or a gas monitoring device including one or more gas sensors, a concentration of one or more components of a gas mixture to be delivered to a patient. For example, step 1222 may include obtaining a sample gas stream of a gas mixture to be delivered to a patient and measuring a concentration of one or more components of the sample gas stream. The one or more gas sensors or gas monitoring devices may communicate with the control device via a wired connection or a wireless connection. Step 1222 may include sending a sensing signal or reading from one or more gas sensors or gas monitoring devices to a control device. In some embodiments, step 1222 includes providing an alert when one or more readings of one or more gas sensors are above or below a threshold. The alert may be of any suitable form, such as an audible or visual alert, for any suitable duration.

In some embodiments, step 1222 includes controlling the flow of the product gas to mix or combine with a flow of gas (such as an air flow or an oxygen flow) supplied by a respiratory device (such as a ventilator). For example, the control device may be in communication with a flow control device configured to control the flow of product gas from the NO system. The control means may send instructions to the flow control means to adjust the flow rate of the product gas. The control device may generate instructions based on one or more sensing signals or readings of one or more flow sensors and/or one or more gas sensors.

In some embodiments, step 1222 includes controlling the flow of air or oxygen supplied by the ventilator. For example, the control device may be in wired or wireless communication with the ventilator. The control means may send instructions to the ventilator to adjust the flow rate of the air or oxygen flow.

In some embodiments, step 1222 includes operating the gas monitoring device during one or more operations to measure a concentration of one or more components of the gas mixture to be delivered to the patient. For example, step 1222 may include performing one or more of an initialization process, a cleaning process, a sampling process, and a calibration process.

The foregoing description has been presented for purposes of illustration. They are not intended to be exhaustive and are not limited to the precise forms or embodiments disclosed. Modifications and adaptations to the embodiments will be apparent from consideration of the specification and practice of the disclosed embodiments. For example, the described embodiments include hardware, but systems and methods consistent with the present disclosure may be implemented in hardware and software. Furthermore, although certain components have been described as being connected to one another, these components may be integrated with one another or distributed in any suitable manner.

Moreover, although illustrative embodiments have been described herein, the scope includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as based on the present disclosure. Furthermore, the steps of the disclosed methods may be modified in any manner, including reordering steps or inserting steps or deleting steps.

Features and advantages of the present disclosure are apparent from the detailed description. Further, since numerous modifications and variations will readily occur upon a study of the disclosure, it is not desired to limit the disclosure to the exact configuration and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the disclosure.

It should be understood that the above-described embodiments may be implemented in hardware, software (program code), or a combination of hardware and software. If implemented in software, it may be stored in the computer-readable medium described above. When implemented by a processor, the software may perform at least some of the steps of the disclosed methods.

In the foregoing specification, embodiments have been described with reference to numerous specific details that may vary from implementation to implementation. Certain adaptations and modifications of the described embodiments can be made. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims. The order of steps shown in the figures is also for illustrative purposes only and does not imply that all steps must be performed for any given method of operation, nor that all steps are limited to any particular order of steps. Thus, those skilled in the art will appreciate that the steps may be performed in a different order when the same method is performed. Furthermore, the devices shown in the figures are merely illustrative, and a given device or system may include different combinations of components or modules of such devices.

Claims

1. An apparatus for generating nitric oxide, the apparatus comprising:

a reaction chamber having a liquid region configured to contain a reaction medium and a gas region configured to contain a product gas comprising nitric oxide;

a plurality of electrodes disposed in the reaction medium, the plurality of electrodes comprising a cathode;

an energy source electrically connected to the plurality of electrodes and configured to apply a predetermined voltage or a predetermined current to the cathode to generate nitric oxide;

a sparger disposed in the reaction medium;

an inlet circuit in fluid communication with the sparger and configured to deliver a carrier gas to the sparger; and

an outlet circuit in fluid communication with the gas region of the reaction chamber and configured to deliver the product gas from the reaction chamber; and

a first circulation loop configured to circulate a first fluid stream relative to the reaction chamber, the first circulation loop comprising:

a first inlet in fluid communication with a gas region of the reaction chamber;

a first outlet in fluid communication with the sprinkler; and

A first pump configured to generate a first fluid flow from the first inlet to the first outlet.

2. The apparatus of claim 1, wherein the carrier gas comprises nitrogen.

3. The apparatus of claim 2, wherein the first fluid stream comprises a product gas stream.

4. The apparatus of claim 1, wherein the sparger is disposed adjacent to the cathode and the sparger is configured to emit bubbles in the reaction medium to propagate along the surface of the cathode.

5. The apparatus of claim 4, wherein the sparger is configured to, in one stage, emit bubbles comprising a carrier gas in the reaction medium, and, in a further stage, emit bubbles comprising a carrier gas and a nitric oxide gas in the reaction medium.

6. The apparatus of claim 1, further comprising a second circulation loop configured to circulate a second fluid flow relative to the reaction chamber, the second circulation loop comprising:

a first port in fluid communication with a liquid region of the reaction chamber;

A second port in fluid communication with a gas region of the reaction chamber;

a second pump configured to generate a second fluid flow from the first port to the second port or from the second port to the first port; and

a liquid-gas separation device disposed downstream of the second pump and configured to separate nitric oxide from the reaction medium as the reaction medium passes therethrough.

7. The apparatus of claim 1, wherein the reaction medium comprises a buffer solution, a nitrite ion source comprising one or more nitrites, and a catalyst comprising a metal-ligand complex.

8. The apparatus of claim 1, further comprising a nitric oxide sensor configured to detect a nitric oxide concentration of the product gas.

9. The apparatus of claim 5, further comprising a pressure vessel in fluid communication with the outlet circuit, the pressure vessel configured to receive product gas from the outlet circuit, store the received product gas at or below a predetermined pressure, and release the received product gas.

10. An apparatus for generating nitric oxide, the apparatus comprising:

a sparger disposed in the reaction medium;

a first circulation loop, the first circulation loop comprising:

a first inlet in fluid communication with a gas region of the reaction chamber;

a first outlet in fluid communication with the sprinkler; and

a first pump configured to generate a product gas stream from the first inlet to the first outlet;

The first circulation loop is configured to recirculate a product gas stream relative to the reaction chamber;

the sparger is configured to emit bubbles comprising a carrier gas into the reaction medium or to emit bubbles comprising a carrier gas and a product gas stream.

11. The apparatus of claim 10, wherein the first pump is a gas pump.

12. The apparatus of claim 10, wherein the carrier gas comprises nitrogen.

13. The apparatus of claim 10, further comprising a pressure vessel in fluid communication with the outlet circuit, the pressure vessel configured to receive product gas from the outlet circuit, store the received product gas at or below a predetermined pressure, and release the received product gas.

14. The apparatus of claim 13, wherein the pressure vessel comprises:

a body defining an interior cavity including a first region and a second region in fluid communication with the first region and disposed downstream of the first region;

a gas inlet and a gas outlet in fluid communication with the first region; and

A plurality of baffles defining a tortuous flow path through the first region and the second region; and

a pressure relief valve disposed on the body and in fluid communication with the second region.

15. A method for generating nitric oxide, the method comprising:

applying a predetermined voltage or a predetermined current to one or more of a plurality of electrodes by an energy source to generate nitric oxide, the plurality of electrodes being disposed in a reaction medium contained in a reaction chamber, the plurality of electrodes comprising a cathode, the reaction chamber comprising a gas region and a liquid region, the liquid region being configured to contain the reaction medium, the gas region being configured to contain a product gas comprising nitric oxide;

receiving a carrier gas through an inlet circuit in fluid communication with a sparger disposed in the reaction medium;

emitting bubbles of the carrier gas in the reaction medium through the sparger to sweep a surface of one or more of the plurality of electrodes;

circulating a first fluid stream in a first circulation loop relative to the reaction chamber, the first fluid stream comprising a product gas stream; and

The product gas is conveyed from the reaction chamber through an outlet circuit that is in fluid communication with a gas region of the reaction chamber.

16. The method of claim 15, wherein circulating the first fluid flow relative to the reaction chamber comprises generating a first fluid flow from a first inlet of the first circulation loop to a first outlet of the first circulation loop by a first pump, the first inlet being in fluid communication with a gas region of the reaction chamber, the first outlet being in fluid communication with the sparger.

17. The method of claim 16, wherein bubbles comprising the product gas are emitted in the reaction medium by the sparger to sweep across a surface of one or more of the plurality of electrodes.

18. The method of claim 15, further comprising delivering the product gas to a pressure vessel in fluid communication with the outlet circuit, the product gas being delivered from the pressure vessel via the gas outlet after a pressure maintenance period.