CA3153422A1 - Method and apparatus for transforming the thermodynamic potential of a gas - Google Patents

Abstract

An apparatus and method for reducing carbon dioxide emissions by surrounding a combustion source with a molecular sieve. The molecular sieve has an inner surface facing the combustion source and defining an inner flow passage; the outer surface may be coated with a metal oxide catalyst. A body having an inner surface facing an outer surface of the molecular sieve defines an outer flow passage. CO2 is dissociated into Carbon Monoxide (CO), Carbon and Oxygen molecules. The Carbon along the outer flow passage is exposed to the outer surface of the molecular sieve, steam is dissociated by carbon releasing oxygen and hydrogen. The Oxygen combines with carbon forming a syngas containing carbon monoxide and hydrogen.

Description

METHOD AND APPARATUS FOR TRANSFORMING THE
THERMODYNAMIC POTENTIAL OF A GAS
TECHNICAL FIELD
The disclosure relates generally to gas transformers, and more particularly to methods and systems for transforming the thermodynamic potential of a gas.
BACKGROUND
Carbon dioxide is known as a "greenhouse" gas and scientists are advising that a reduction in man-made carbon dioxide emissions is essential to slowing climate change. An alternative to producing carbon dioxide from hydrocarbon combustion is to produce carbon monoxide instead, a reactive and useful gas. In industry, coke is generated by burning coal in an oxygen deprived furnace, producing a top gas mixture containing 10% carbon monoxide and 50% hydrogen, commonly known as producer gas.
There is no single complete theory that is able to predict what products will result from combining a number of reactants. Products of a chemical reaction are not only a function of the reactants, but also of temperature, pressure, catalyst present and several other factors.
Because of this gap in scientific knowledge it is necessary to experimentally determine what happens when reactants are brought together under certain conditions.
In applying Boudouard's equilibrium, C + CO2 <==> 2 CO, the ratio of the partial pressures of the gases indicates that at temperatures over about 940 C, mostly carbon monoxide exists during gasification. Throughout historical literature are found methods in the art of generating producer gas, some literature incorrectly teaches "the conversion of carbon dioxide into carbon monoxide inside coal furnaces was due to the glowing char above the grate, by stealing oxygen atoms from carbon dioxide molecules". While the prior art literature states that where carbon dioxide is undesirable it can be dissociated into carbon monoxide and oxygen, it was actually the thermal oxidation of the iron grate itself that was decreasing the carbon dioxide.

Date Recue/Date Received 2022-03-25 Fundamentally, according to the ideal gas law, in a mixture of gases each gas has a specific partial pressure at a specific volume and temperature; the total pressure of the gas mixture is the sum of all the individual gases partial pressures. An equilibrium expression means the sum of the parts must equal the total. The partial pressure of a gas is the equivalent pressure the specified gas alone would exhibit in the same volume at the same temperature.
However, gas molecules in an ideal gas do not interact, whereas in a real gas the partial pressure of a gas is a measure of the thermodynamic activity of the gas's molecules.
The gases in a real mixture react according to their partial pressures, and not according to their concentration in the gas mixture.
In a mixture of interactive gases at equilibrium, the forward reaction and reverse reaction have the same rate. The concentrations of the reaction components stay constant at equilibrium, even though the forward and backward reactions are still occurring. The reaction quotient (Q) measures the relative amounts of products and reactants present during a reaction at a particular point in time. The Q value can be compared to the Equilibrium Constant, K, to determine the direction a reaction will proceed to reach equilibrium. The constant K reflect two measurements of quantity:
If K> 1 - equilibrium favours the products If K < 1 - equilibrium favours the reactants If K = 1 - the mixture contains similar amounts of both products and reactants at equilibrium The equilibrium constant can be calculated using the molar concentration (KO
of the chemicals, or by using their partial pressure (Kr).
Kc is the ratio of concentrations at equilibrium for a reaction at a certain temperature. Calculating the value of the equilibrium constant for a reaction is helpful when determining the amount of each substance formed at equilibrium as a ratio of each other. The constant does not depend on initial concentrations of the reactants and products, as the same ratio will always be reached after a certain period of time, when the reaction is stable.
When a reaction component is a gas, we can also express the amount of that chemical at equilibrium in terms of its partial pressure. When the equilibrium constant is written with the gases in terms of partial pressure, the equilibrium constant is written as the symbol K.
Each component of a gaseous mixture will contribute to the total pressure exerted by the mixture proportionally to the number of molecules in has in the mixture. One mol of any substance is equal

- 2 -Date Recue/Date Received 2022-03-25 to exactly 6.022 x 1023 molecules of that substance; this is known as Avogadro's number. This means that you an express the number of mols of a gas by using the number of molecules; the percent composition of a gaseous mixture tells you how many molecules each gas contributes to 100 molecules of the mixture.
For example, air at standard atmospheric pressure and temperature, STP, is said to be approximately 0.004% carbon dioxide. This means that in every 100 molecules of air, 0.4 will be CO2 molecules.
The "partial pressure" of a gas is a thermodynamic characteristic that enables us to determine the concentration of a gas at a given pressure and temperature. Once we know this, we can then calculate the concentrations or partial pressures of the reaction species at equilibrium. Then, if the partial pressures of gases in a mixture are sufficiently different, the method of shifting the equilibrium by adjusting the reactor pressure and or temperature will increase the concentration of one product gas over another prior to quenching.
We can convert between gas concentration and partial pressure using the ideal gas equation. We can use this relationship to derive an equation to convert directly between Ke, and at temperature, T, in Kelvin, where R is the correct gas constant; for example 0.082057 is based on the units K=mol/L=atm:
Kp = (KcRT) nA
The symbol nA is the number of moles of gas on the product side minus the number of moles of gas on the reactant side of a properly balanced chemical equation. To save time, start calculations with the change in the number of moles. If it's zero (An = 0) then Kc equals Kp.
The theoretical predictions of the rates of product generated by any chemical reactions require experimental data acquired by scientifically accepted methods. For example, in the prior art patent EP2794466B1 titled "Process and system for conversion of carbon dioxide to carbon monoxide", the method claims "the CO2 converter operates according to part of the blast furnace reaction known in the art, CO2 + C ¨> 2CO3 which occurs between approx. 750 and 1200 Celsius proceeds without the need for a catalyst".
This method implies that CO2 can be reduced by carbon into carbon monoxide, between 750 and 1200 C, without a catalyst. The patent further discloses that at 800 C the carbon monoxide is about 94%, and about 1000 C about 99% CO is produced. While the patent provides the reaction

- 3 -Date Recue/Date Received 2022-03-25 product composition at process temperature, these figures are calculated using Boudouard's equilibrium for gasification.
It is known that when a gas rich in CO is cooled to the point where the activity of carbon exceeds one, the Boudouard reaction can take place. However, this reaction indicates that carbon monoxide tends to disproportionate into carbon dioxide and graphite, which forms soot.
It does not imply the reaction is reversible.
In the blast furnace, the prior art literature correctly references the chemical equation for the equilibrium constant, however when calculating an equilibrium constant for gases involving reaction with a catalyst, the catalyst is not included in the equilibrium equation.
The first step in determining an equilibrium constant requires a balanced chemical equation, then determine the reaction quotient Q to establish which direction the reaction will go to reach equilibrium:
CO2 + C ¨> 2C0 The most important thing to remember when calculating the equilibrium constant in terms of pressure is to only take into account components in the gas phase. The partial pressure of an individual gas is equal to the total pressure multiplied by the mol fraction of that gas. We can write Kp for reactions that include solids and pure liquids since they do not appear in the equilibrium expression. Here we have one mol of CO2 reacting with one mol of carbon which cannot be a gas so we can ignore carbon; next we have 2 mols of CO being produced. Thus:
Ke = concentration of product / concentration reactants Kc = 0.94 / (1.00 ¨ 0.94) = 15.66 nA = mols product ¨ mols of reactants = 2 ¨ 1 = 1 Kp = Ke RVn = 15.6 x 0.082057 x 800 + 2731 = 1379 The general formula for Kp of a mixture of gases is equal to the ratio of the sum of the partial pressures of the products to the sum of the partial pressures of the reactants. Accordingly, when the equilibrium value K > 1, it indicates the forward reaction dominates to create the product, carbon monoxide, at 800 C. Since the Kp of a mixture of gases does not change, in a reversible reaction a change in the total pressure, temperature or gas mixture concentrations will shift the equilibrium.

- 4 -Date Recue/Date Received 2022-03-25 The equilibrium constant can be derived by experimental or computational methods; when derived by computational methods it must be confirmed experimentally to determine the true value of the equilibrium constant for a reaction.
Therefore, it is necessary to measure the concentrations of the reactants and/or products while a stable equilibrium is established at the measured temperature. The reactor used in the process of carrying out the reaction experimentally must be completely inert at operating temperatures and pressure; otherwise, some unknown agent may serve as a catalyst.
A catalyst is a substance that increases the rate of a chemical reaction without any permanent chemical change. A reversible reaction is a reaction where the forward reaction produces products while simultaneously the reverse reaction converting the products back into reactants.
Scientists know that carbon dioxide does not dissociate even at high temperatures without a "catalyst" and to date while a number of catalysts for carbon dioxide reduction of greenhouse gases have been proposed, none have been found economical. To be economical a catalyst should last a long time.
An activity series is the order of metals based on their reactivity from highest to lowest. Metals from potassium to calcium are highly reactive, while metals from magnesium to lead can react with acids. Metals from copper to platinum are highly unreactive under normal conditions; most significantly they don't oxidize easily. Metals such as zinc, iron, aluminium, magnesium, calcium form oxides readily.
In the blast furnace, the prior art literature correctly references the chemical equation for the equilibrium constant CO2 + C ¨> 2CO3 however when calculating an equilibrium constant for gases involving reaction with a catalyst, the catalyst is not included in the equilibrium equation.
While it is known that CO2 reacts with coke carbon consuming energy, whereas Hz, Nz, and CO
do not; it is the CO that reduces iron oxides to iron.
It is known that stable gases do not dissociate at high temperatures unless an element is present;
and the element must form an oxide. Therefore, the complete reversible reaction then must include the simultaneous reduction of an element and its oxide according to the activity series.
Again, referring to prior art, the conversion of CO2 to long chain hydrocarbons has been established to go through a two-stage reaction mechanism over iron catalysts, it was with the initial

- 5 -Date Recue/Date Received 2022-03-25 conversion of CO2 to CO on the iron's magnetite phase, followed by Fischer-Tropsch synthesis.
(Lox, E. S, and Froment, G. F., Industrial & Engineering Chemistry Research 32 (1), 71(1993)) The blast furnace is used in iron making where iron oxide is reducing carbon monoxide forming iron, FeO + CO ¨> Fe + CO2; while simultaneously the reverse reaction of carbon dioxide oxidizing the iron back into iron oxide forming carbon monoxide, Fe + CO2 ¨>
FeO + CO.
Therefore, it was the iron forming iron oxide inside the blast furnace that provides the catalyst for the dissociation of carbon dioxide to carbon monoxide, not high temperature.
Boudouard's equilibrium determines the stable composition of a mixture of gases at a given total pressure, or the sum of their individual partial pressures, at a given temperature. However, the Boudouard reaction was based on gasification of coal; an oxidation process.
This means oxygen is supplied to create an oxide of carbon, carbon monoxide.
The balanced chemical equation for the gasification of carbon is: 4C + 302 ¨>
2C0 + 2CO2, Boudouard's equilibrium states that at higher temperatures carbon monoxide dominates the products. Conversely, as the carbon monoxide cools, in the presence of oxygen, carbon dioxide will form.
The Boudouard reaction clearly illustrates the problem presently being encountered; that while hot, carbon monoxide is "short lived" and, if exposed to the "air", will soon recombine with oxygen forming carbon dioxide again. Excess carbon monoxide absent of oxygen will form soot, while the soot deposits are known to poison the catalyst.
A transformer in electrical terms changes the voltage, or potential to do work. In a similar manner increasing the temperature of a mixture of gases increases their reaction potential; conversely cooling the mixture of gases may prevent their reaction.
SUMMARY
The apparatus herein described as a gas transformer and methods to control the product composition of a mixture of thermodynamic reactive gases by changing the total pressure at a given temperature followed by quenching, rapidly reducing the temperature of the gas mixture.
Without quenching the gas mixture, the reverse reaction, or recombination, of the products occurs as the gas mixture cools.
Furthermore, in addition to the apparatus and method of controlling the gas mixtures, the total pressure, temperature and quenching the gas mixture; with the addition of an appropriate catalyst,

- 6 -Date Recue/Date Received 2022-03-25 it that has been found to shift Boudouard's equilibrium, increasing the partial pressure, or the concentration of carbon monoxide produced by combustion at about 820 C.
Subsequently, when Boudaouard's equilibrium exceeds unity, the result may be excess carbon monoxide; while the shifted equilibrium may allow a higher concentration of carbon monoxide before soot forms.
Water gas may be produced when water may be used to rapidly cool the coke after being discharged from the coal furnaces. In a similar manner, a method of injecting water into the gas transformer utilizes the elemental carbon, or soot, formed as a catalyst to dissociate supplemental water vapour.
Elemental carbon can catalytically dissociate water into hydrogen and reactive oxygen.
Accordingly, Boudouard's equilibrium indicates that for a given total pressure and temperature, the reactive oxygen combines with elemental carbon forming carbon monoxide.
Now instead of hydrocarbon combustion producing carbon dioxide in our atmosphere, a concentrated mixture of carbon monoxide and hydrogen may be produced; known in the art as synthetic gas, or syngas. Once syngas containing carbon monoxide and hydrogen has been derived, a Fisher-Tropsch chemical process can be used to convert the gaseous carbon monoxide and hydrogen into liquid hydrocarbons.
According to one aspect, there is provided a method for reducing carbon dioxide emissions. A step may be taken of surrounding a combustion source with a tubular porous ceramic sleeve. The ceramic sleeve has an inner surface facing the combustion source defining an inner flow passage and an outer surface.
An elongated member may be concentrically positioned within the inner flow passage of the ceramic sleeve. The elongated member provides a number of advantages. An advantage may be that it may allow a helical flow to be induced around the elongated member.
A helical flow increases the time the combustion gases take to move along the inner flow passage.
This maintains the temperature all along the inner flow passage. If a catalyst is being used, the elongated member will distribute the heat assisting uniform catalytic reaction.
Typically, combustion gases contain a substantial quantity of nitrogen gas in combination with carbon dioxide. A helical flow tends to push the heavier carbon dioxide containing gases outward, separating the relatively lighter nitrogen and carbon monoxide gases from the still lighter hydrogen containing fuel gases; these are forced closer to the elongated member.

- 7 -Date Recue/Date Received 2022-03-25 Although the elongated member could be a solid metal or ceramic rod and function, as described above, it may be preferred that the elongated member be tubular. This enables exhaust containing CO2 gas from a secondary source to be heated while passing along inside the tubular elongated member. In addition, a tubular elongated member provides a conduit to deliver water vapour from a secondary source to be heated to steam within the tubular elongated member.
A step may be taken of surrounding the inner ceramic sleeve with an outer assembly. The outer assembly has a peripheral sidewall having an inner surface facing the outer surface of the inner ceramic sleeve and defining an outer flow passage.
The second longer outer assembly may be positioned concentrically within the central bore of the .. inner ceramic sleeve. The outer assembly has a first end, a second end and a circumferential wall having an inner surface and an outer surface. The circumferential wall may be closed with a peripheral U-turn transition where the inner flow passage connects to the outer flow passage. The U-turn may be a flat or curved shape terminating the tubular form.
The cavity formed between the inner surface of the outer assembly and the outer surface of the .. inner ceramic sleeve defines a flow passage. The cavity may be void, partially or completely filled with a metal oxide framework, MOF, catalyst. In an embodiment the outer surface of the inner ceramic sleeve may be coated with an MOF catalyst containing iron oxide while the outer surface of the outer assembly remains bare.
A step may be taken of surrounding the outer assembly with a tertiary tubular sleeve. The outer surface of the second tubular assembly forms an annular outer flow passage with the inner surface of the peripheral sidewall of the tertiary tubular body, forming an outer housing.
A burner input connection may be positioned at the first end of tubular ceramic sleeve in fluid or flow communication with the inner flow passage. An outlet may be provided on the outer housing wall for processed combustion gases, which are then sent for separation and further processing.
A step may be taken of combusting a hydrocarbon fuel with minimum air, raising the temperature of a mixture of the resulting combustion gases containing a ratio of carbon monoxide (CO) and carbon dioxide (CO2), and inducing a helical rotation in the gases about the tubular elongated member. The velocity of the helical vortex about the tubular elongated member may be sufficient to induce a Burgers vortex near the surface of the elongated member, while at the outer surface of .. the inner molecular sieve the helical velocity forms uniform rotational flow.

- 8 -Date Recue/Date Received 2022-03-25 The Burgers vortex velocity may be sufficient to induce separation of gases by density whereas the outer rotational flow contains mixed gases. When the gases enter the U-turn, they are folded in the U-turn, aided by a gas funnel formed by folding the gases over the outer surface of the inner ceramic sleeve. Here the denser carbon containing exhaust may be folded into the MOF catalyst, .. which having being uniformly heated causes the CO2 to dissociate into carbon monoxide (CO) and reactive oxygen.
During the folding of the combustion gases in the U-turn, the helical rotation likewise folds the nitrogen gas forming a shield gas layer between the inner surface of the outer assembly and the MOF. Furthermore, as an alternative to discharging CO2 into our atmosphere, exhaust gas from an industrial process may be passed into the apparatus, the tubular form of the elongated member raises the temperature of the exhaust gas from the industrial process before transforming the carbon dioxide into carbon monoxide via the MOF catalyst.
The hot exhaust gas containing CO2 enters the MOF where Fe may be oxidized to FeO forming CO, the CO combines with the nitrogen shield gas and the combustion gases folded in the U-turn section causing the partial pressure of carbon monoxide to exceed unity. At certain total pressure and temperature, exceeding unity results in free carbon being formed.
In the folding process the hot nitrogen and carbon monoxide shields the MOF
catalyst from the hydrogen and resulting free carbon formed in the outer flow passage so that they are restricted to the inner surface of the outer assembly.
A further step of introducing water vapour via the tubular elongated member into the U-turn in combination with the free carbon and hot gases causes the formed steam to dissociate into free hydrogen and reactive oxygen. The reactive oxygen combines with the free carbon forming carbon monoxide. The nitrogen forms a shield gas between the carbon and oxygen forming carbon monoxide in the outer region from the carbon dioxide dissociating to reactive oxygen and carbon monoxide in the inner MOF region.
Although the basic partial pressure method and apparatus are identified above, in an embodiment which will hereinafter be described a number of features have been added to enhance operation.
In an embodiment, an outer housing has been provided. The outer housing has a first end, a second end and a peripheral sidewall that defines a housing cavity. The tubular body may be positioned within the housing cavity, with the outer surface of the tubular body forming an outermost flow passage with the peripheral sidewall of the outer housing. A quenching zone may be provided

- 9 -Date Recue/Date Received 2022-03-25 where the outer flow passage connects to the outermost flow passage. The outermost flow passage provides a cooling zone to rapidly cool the carbon monoxide containing product gases. The quenching zone restricts the outflow from the outer flow passage as will hereinafter be further described.
In an embodiment, a flow restriction may be positioned at the quenching zone transition forming a subsequent cooling zone. The flow restriction serves to choke the flow. A
suction source may be connected to the outermost flow passage for the purpose of counteracting back pressure caused by the flow restriction and capturing the quenched gas.
A gas under pressure forced through a restricted, or convergent, opening to a zone of lower pressure may be choked or reaches a critical flow; lower pressure in a subsequent divergent zone creates a cooling effect on the hot gas. The lower the pressure on the divergent side, the higher the gas velocity; this provides variation from subsonic through supersonic velocity to rapidly decrease the gas temperature.
The maximum gas velocity in an orifice may be limited by the speed of sound of the gas and the area of the orifice; both the mass flow and composition are proportional to the ultrasonic signature, whereas the gas temperature has little effect. Thus, the restriction forming the quenching zone induces sonic velocity with the suction producing subsonic through supersonic discharge velocity.
Therefore, the quenching zone rapidly drops the temperature of the carbon monoxide containing gas below 400 C, preferably as low as 200 C, preventing the formation of carbon dioxide.
In an embodiment, a conducted ultrasound transducer may be in communication with the outer flow passage at the flow restriction. The use of ultrasound serves several valuable functions. There needs to be some manner of determining what proportion of carbon dioxide has been converted to carbon monoxide. Ultrasound pitch can be used to monitor the ratio of CO2 to CO. This may be possible because of a difference in relative densities of CO2 and CO, which result in a corresponding difference in their sonic signatures. The ultrasound intensity also provides a measurement of the gas velocity passing through the restriction at the quenching zone. The gas composition and velocity can be used to calculate the mass flow of the gases.
According to another aspect there may be provided an apparatus for reducing carbon dioxide emissions, which includes a tubular body having a first end, a second end and a peripheral sidewall having an inner surface and an outer surface. The inner surface defines a central bore. The inner

- 10 -Date Recue/Date Received 2022-03-25 tubular ceramic sleeve may be a porous NbSiC material with conductive or semi-conductive characteristics forming a molecular sieve.
An electrical control assembly may be provided for energizing the outer assembly made from either a stainless or a porous NbSiC material with conductive or semi-conductive characteristics via a high voltage power source. Typically 25kv or less may be connected between the metal tubular elongated member and the outer assembly for the purpose of electrostatically attracting the ionized oxygen atoms from the catalytic zone to the elongated member in the combustion zone through the porous ceramic sleeve.
In an aspect, the disclosure describes a method for reducing carbon dioxide emissions. The method also includes surrounding a combustion source with a molecular sieve, the molecular sieve having an inner surface and an outer surface, the inner surface facing the combustion source and defining an inner flow passage; surrounding the molecular sieve with a body, the body having a peripheral sidewall having an inner surface facing the outer surface of the molecular sieve and defining an outer flow passage; raising a temperature of a mixture of combustion gases containing carbon dioxide (CO2), passing the mixture of gases along the outer flow passage exposed to the outer surface of the metal oxide framework coated molecular sieve; catalytically reducing the carbon dioxide to CO by iron forming iron oxide within the pores of the metal oxide forming free carbon;
increasing free oxygen liberated from iron oxide reduced by carbon monoxide within the metal oxide framework; and forming carbon monoxide by oxidizing free carbon with free oxygen.
Implementations may include one or more of the following features. The method wherein an elongated metal member is positioned in the inner flow passage and a helical flow is induced through the elongated metal member. The elongated metal member is tubular and combustion gases from a secondary source are passed along the elongated metal member for processing.
Conducted ultrasound is used to monitor a conversion of CO2 to CO based upon a difference in relative densities of CO2 and CO. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.
In an aspect, the disclosure describes an apparatus for reducing carbon dioxide emissions. The apparatus also includes a tubular body having a first end, a second end and a peripheral sidewall having an inner surface that defines a central bore and an outer surface; an electrical control assembly for connecting the tubular body to a power source for purposes of selectively supplying an electrical current to cause the tubular body to function as a semi-conductor; a porous tubular Date Recue/Date Received 2022-03-25 molecular sieve positioned concentrically within central bore of the tubular body, the porous tubular molecular sieve having a first end, a second end and a circumferential wall having an inner surface and an outer surface, the inner surface defines an inner flow passage and the outer surface forms an outer flow passage with the inner surface of the peripheral sidewall of the tubular body;
a first transition connection where the inner flow passage connects to the outer flow passage; a burner input connection being positioned at a first end of the inner flow passage; and an outlet for processed combustion gases.
Implementations may include one or more of the following features. The apparatus wherein an outer housing is provided, the outer housing having a first end, a second end and a peripheral sidewall that defines a housing cavity; the outer surface of the tubular body forming an outermost flow passage with the peripheral sidewall of the outer housing; and a second transition connection being provided where the outer flow passage connects to the outermost flow passage. A flow restriction is positioned at the second transition connection. A conducted ultrasound transducer is in communication with the outer flow passage at the flow restriction. A
suction source is connected to the outermost flow passage for purposes of counteracting back pressure caused by the flow restriction. An elongated metal member is concentrically positioned within the inner flow passage of the porous tubular molecular sieve, the elongated metal member having a first end and a second end. The elongated metal member is tubular. The tubular body is a non-porous conductive ceramic.
The porous tubular molecular sieve is a porous non-conductive ceramic.
Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.
In an aspect, the disclosure describes an apparatus for reducing carbon dioxide emissions. The apparatus also includes an outer housing having a first end, a second end and a peripheral sidewall that defines a housing cavity; a tubular body of non-porous conductive ceramic positioned within the housing cavity of the outer housing, the tubular body having a first end, a second end and a peripheral sidewall having an inner surface and an outer surface, the inner surface defines a central bore, and the outer surface defines an outermost flow passage with the peripheral sidewall of the outer housing; an electrical control assembly for connecting the tubular body to a power source for purposes of selectively supplying an electrical current to cause the tubular body to function as a semi-conductor; a porous tubular molecular sieve of porous non-conductive ceramic positioned concentrically within central bore of the tubular body, the porous tubular molecular sieve having a first end, a second end and a circumferential wall having an inner surface and an outer surface, Date Recue/Date Received 2022-03-25 the inner surface defines an inner flow passage and the outer surface forms an outer flow passage with the inner surface of the peripheral sidewall of the tubular body; an elongated tubular metal member concentrically positioned within the inner flow passage of the porous tubular molecular sieve, the elongated tubular metal member having a first end and a second end;
a first transition connection where the inner flow passage connects to the outer flow passage, the second end of the elongated tubular metal member terminating at the first transition connection;
a second transition connection where the outer flow passage connects to the outermost flow passage, a flow restriction is positioned at the second transition connection; a conducted ultrasound transducer in communication with the outer flow passage at the flow restriction; a suction source connected to the outermost flow passage for purposes of counteracting back pressure caused by the flow restriction; a burner input connection being positioned at the first end of the inner flow passage;
and an outlet for processed combustion gases in flow communication with the outermost flow passage.
Embodiments can include combinations of the above features.
Further details of these and other aspects of the subject matter of this application will be apparent from the detailed description included below and the drawings.
DESCRIPTION OF THE DRAWINGS
These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:
FIG. 1 is a perspective view of an apparatus for reducing carbon dioxide emissions, with burner attached, in accordance with an embodiment;
FIG. 2 is a front elevation view, in section, of the apparatus with burner of FIG. 1, in accordance with an embodiment;
FIG. 3 is an exploded perspective view of the apparatus with burner of FIG. 1, in accordance with an embodiment;
FIG. 4 is a detailed perspective view of an outer tubular assembly of the apparatus of FIG. 1, isolated from other components, with the U-turn and orifice details shown, in accordance with an embodiment;

Date Recue/Date Received 2022-03-25 FIG. 5 is a bottom plan view of the outer assembly of FIG. 1, showing a relationship between the inner and outer orifice openings, in accordance with an embodiment, in accordance with an embodiment;
FIG. 6 is a first simplified side elevation view, in section, of the apparatus of FIG. 1 to demonstrate operation, in accordance with an embodiment, in accordance with an embodiment;
FIG. 7 is a second simplified side elevation view, in section, of the apparatus of FIG. 1 to show operation of the apparatus, in accordance with an embodiment;
FIG. 8 is a detailed perspective view of an outer assembly with an exemplary U-turn that is hemispherical, in accordance with an embodiment;
FIG. 9 is a detailed perspective view of an outer assembly with an exemplary U-turn including a nozzle, in accordance with an embodiment; and FIG. 10 is a perspective "X-ray" view of an apparatus for reducing carbon dioxide emissions, with burner attached, in accordance with an embodiment.
DETAILED DESCRIPTION
Aspects of various embodiments are described in relation to the figures.
An apparatus 10 for reducing carbon dioxide emissions will now be described with reference to FIG. 1 through FIG. 10.
Apparatus 10 was constructed to facilitate a method for reducing carbon dioxide emission; this method will first be described. Referring to FIG. 1, FIG. 2, and an "X-ray"
(see-through) view in FIG. 10, apparatus 10 is shown attached to a burner 12. Burner 12 directs a rotating vortex flame into apparatus 10. In the description of the method which follows, the open flame of burner 12 may be considered to be the combustion source. Referring to FIG. 6, a step in the method may involve surrounding a combustion source with a porous tubular nitride bonded silicon carbide, NbSiC, ceramic sleeve 14. Ceramic sleeve 14 may have an inner surface 16 facing the combustion source and an outer surface 18. Inner surface 16 may define an inner flow passage 20. Ceramic sleeve 14 may also be referred to as a molecular sieve or porous tubular molecular sieve.
A step may involve surrounding ceramic sleeve 14 with a body (see outer assembly 22). The body may have been illustrated as a tubular body, having a peripheral U-turn 24 including an inner surface 26 that defines a central bore of the tubular body and an outer surface 28. The body with Date Recue/Date Received 2022-03-25 integral U-turn 24 surrounding the inner ceramic sleeve 14 may form the outer assembly 22. Timer surface 26 of outer assembly 22 faces outer surface 18 of inner ceramic sleeve 14 and may define an outer flow passage 30.
A step may involve raising the temperature of a mixture of hydrocarbon fuel and a minimum amount of air to produce carbon dioxide (CO2) and carbon monoxide (CO) with minimal free Oxygen (02) molecules.
A step may involve spinning the mixture of combustion gases about elongated member 70 inside inner flow passage 20. The spinning mixture of combustion gases containing carbon dioxide, being the highest density gas, may rotate faster and may be forced outwards to the inner surface 16 of the ceramic sleeve 14, while nitrogen (N2) and carbon monoxide form a rotating ring of lower density gases concentrated about the elongated member 70. Hydrogen and unburnt hydrocarbons being the lowest density gases rotate with the least velocity, remaining concentrated closest to the elongated member 70.
STRUCTURE AND RELATIONSHIP OF PARTS
Referring to FIG. 2, apparatus 10 may have an outer housing 40 with a first end 42 (lower end), a second end 44 (upper end) and a peripheral sidewall 46 that may define a housing cavity 48.
Referring to FIG. 2, outer assembly 22 may be made of a stainless steel or a porous semi-conductive nitride bonded silicon carbide ceramic sleeve, positioned within housing cavity 48 of outer housing 40. Referring to FIG. 3, outer assembly 22 may have a first end 50 (lower end) and a second end 52 (upper end). Referring to FIG. 6, as described above in relation to the method, outer assembly 22 may have a peripheral U-turn 24 having an inner surface 26 and an outer surface 28. The inner surface 16 of ceramic sleeve 14 and the inner surface 26 of outer assembly 22 may define a divergent zone 54. Outer surface 28 may define an outermost flow passage 56 with peripheral sidewall (see housing cavity 48) of outer housing 40.
A high voltage power supply 58 may be provided for connecting outer assembly 22 to a power source (not shown) for the purpose of selectively supplying a high voltage between outer assembly 22 and an elongated metal member 70 to function as an electrostatic attractor.
The function of outer assembly 22 as a porous semi-conductor will hereafter be further described in relation to operation.

Date Recue/Date Received 2022-03-25 Referring to FIG. 6, as described above in relation to the method, a porous semi-conducting nitride bonded silicon carbide ceramic sleeve 14, may be positioned concentrically within divergent zone 54 of outer assembly 22. Referring to FIG. 3, semi-conducting ceramic sleeve 14 having a first end 60 (lower end), a second end 62 (upper end) and a circumferential wall 64.
Referring to FIG.
6, circumferential wall 64 may have an inner surface 16 and an outer surface 18. Inner surface 16 may define an inner flow passage 20. Outer surface 18 may form an outer flow passage 30 with inner surface 26 of peripheral U-turn 24 of outer assembly 22.
Referring to FIG. 2, elongated metal member 70 may be concentrically positioned within inner flow passage 20 of ceramic sleeve 14. Referring to FIG. 3, elongated member 70 may have a first end 72 (lower end) and a second end 74 (upper end). Referring to FIG. 2, first end 72 connects with burner 12.
Referring to FIG. 3, this exploded view shows the relationship of outer housing 40, outer assembly 22, tubular ceramic sleeve 14 and elongated metal member 70.
Referring to FIG. 7, the divergent U-turn zone 80 (defining a first transition zone or first transition connection) may be provided at second end 62 (upper end) of ceramic sleeve 14 and second end 52 of outer assembly 22 where inner flow passage 20 connects to outer flow passage 30. Second end 74 of tubular elongated metal member 70 terminates in the vicinity of the divergent U-turn zone 80.
A quenching zone 90 (defining a second transition zone or second transition connection) may be positioned at first end 50 (lower end) of outer assembly 22 and first end 42 (lower end) of outer housing 40 where outer flow passage 30 connects to outermost flow passage 56.
Referring to FIG.
5, a flow restriction 92 may be positioned forming the quenching nozzle. Flow restriction 92 may be in the form of four to six openings (as opposed to an annular opening) where first end 50 of outer assembly 22 may be positioned relative to outer housing 40.
Combustion gases must flow through flow restriction 92 in order to reach outermost flow passage 56. Referring to FIG. 4, the formation of the flow restriction 92 at first end 50 (lower end) of outer assembly 22 is shown. Referring to FIG. 6, a suction source 100 may be connected to the output of outermost flow passage 56 for the purpose of counteracting back pressure caused by the flow restriction.
Referring to FIG. 7, a conducted ultrasound transducer 102 may be in fluid or flow communication with the outer housing in the vicinity of the first end 42 near flow restriction 92. The function of Date Recue/Date Received 2022-03-25 conducted ultrasound transducer 102 (or emitter) will hereinafter be further described in relation to operation.
Referring to FIG. 2, a burner input connection 104 may be positioned at first end 60 (lower end) of ceramic sleeve 14 in fluid or flow communication with inner flow passage 20.
Referring to FIG. 2, an access opening 106 may be positioned at second end 44 of outer housing 40. This access opening may be closed by a plug when apparatus 10 is used with outer assembly 22 using a flat U-turn 24 as shown in FIG. 4, or a hemispherical U-turn as shown in FIG. 8. FIG.
9 shows an example outer assembly 22 with U-turn 24 shown as a nozzle. When outer assembly 22 incorporates a U-turn 24 with a nozzle, the nozzle may be connected to opening 106.
Referring to FIG. 9 and FIG. 1, in the example of outer assembly 22 and nozzle shaped U-turn 24, outlet 108 provides for removing processed combustion gases in fluid or flow communication with outermost flow passage 56. Access opening 106 may be in fluid or flow communication with a flow passage (the divergent zone 54). Here, the nozzle may permit discharging the hydrogen containing combustion gases while the denser carbon containing gases follow the U-turn 24 entering the catalytic zone via the outer flow passage 30.
Apparatus 10 may be more effective when a catalyst is used. Several metal-oxides may be suitable for use as catalysts, although the methodology that is described differs. The selected catalyst may be applied to outer surface 18 of circumferential wall 64 of ceramic sleeve 14.
OPERATION
The prior art literature indicates that carbon dioxide will oxidize iron to iron oxide forming carbon monoxide at temperatures below 900 degrees Celsius. Referring to FIG. 2, burner 12 may be used to heat and maintain inner flow passage 20 at a temperature between 820 and 850 degrees Celsius.
Referring to FIG. 6, at the target temperature of between 900 and 1000 degrees, elongated member 70 conducts heat and helps to maintain that portion of inner flow passage 20 which may be remote from burner 12 at the target temperature of between 820 and 850 degrees.
Burner 12 may not form part of apparatus 10, but may connect to apparatus 10 as a heat source.
Referring to FIG. 1, burner 12 may have gas input 120 for input of fuel gas, an ignitor 122 to ignite the fuel gas and an air input 124 to provide a source of combustion air. Referring to FIG. 6, air input 124 may be connected to a blower 126, which imparts a helical high velocity vortex around elongated member 70 to flow along inner flow passage 20 (or path), as represented by Date Recue/Date Received 2022-03-25 arrows of the high velocity vortex 128. This high velocity vortex 128 increases the residence time of combustion gases flowing along inner flow passage 20. The high velocity vortex 128 also tends to push the heavier carbon containing exhaust gases outward, leaving the relatively lighter nitrogen and hydrogen containing gases closer to the elongated member 70.
Referring to FIG. 7, the method can be understood by considering "zones" where changes are occurring. That portion of inner flow passage 20 near first end 60 of ceramic sleeve 14 may be an oxidation zone 140 where oxygen mixes with the fuel gas to create combustion.
That portion of inner flow passage 20 approaching second end 62 of ceramic sleeve 14 may be a reduction zone 142 where the oxygen may be reduced by combustion. At the U-turn zone 80 at second end 62 (upper end) of ceramic sleeve 14 and second end 52 (upper end) of outer assembly 22 inner flow passage 20 connects to outer flow passage 30. This may be the U-turn zone 80 (or U-turn area) where gas folding without turbulent mixing occurs.
Outer flow passage 30 may be a catalytic zone 144. While traversing this zone, a reaction occurs with the catalyst on outer surface 18 of circumferential wall 64 of ceramic sleeve 14, which serves to dissociate the carbon dioxide into carbon monoxide and oxygen. However, if the oxygen is not removed it may recombine with the carbon monoxide to form carbon dioxide when the cooling occurs.
In order to assist removing the oxygen, an electrical control assembly (power source, or high voltage power supply 58) supplies sufficient high voltage to outer assembly 22. When outer assembly 22 is a porous ceramic semiconductor, it is an electron path when high voltage is applied.
The purpose may be to form a high voltage field that repels free oxygen, such that the oxygen is drawn through the porous NbSiC ceramic sleeve 14 into the oxidation zone 140, where the excess oxygen may be consumed by combustion.
Referring to FIG. 7, the combustion gases reach the quenching zone 90 positioned at first end 50 (lower end) of outer assembly 22 and first end 42 (lower end) of outer housing 40 where outer flow passage 30 connects to outermost flow passage 56. Outermost flow passage 56 may be a cooling zone 146, where the produced gases are cooled.
Referring to FIG. 4, a flow restriction 92 may form the quenching nozzle. Flow restriction 92 may be in the form of four to six openings (as opposed to an annular opening) located at the first end 50 of outer assembly 22. Referring to FIG. 6, combustion gases must flow through flow restriction 92 in order to reach outermost flow passage 56. Suction source 100 may be connected to the output Date Recue/Date Received 2022-03-25 of outermost flow passage 56 for the purpose of counteracting back pressure caused by flow restriction 92.
Referring to FIG. 7, conducted ultrasound transducer 102 may be in communication with outer housing 40 in the vicinity of flow restriction 92. When gas is forced through flow restriction 92, at a differential pressure of 1.85 the velocity of the gas reaches sonic speed. The mass flow of the orifice thus created may be fixed by the upstream pressure and the orifice area. Further decreasing the downstream pressure may not increase the mass flow, yet affects the discharge velocity;
subsonic through supersonic gas velocity may permit rapidly decreasing the gas temperature.
While elongated metal member 70 could have been a solid rod and still function, as described above. Referring to FIG. 7, when the elongated metal member 70 is tubular, it may permit optional gas, for example CO2, to be passed through tubular elongated metal member 70 and admitted to the gases that are exiting the reduction zone 142 for subsequent processing in catalytic zone 144.
This enables apparatus 10 to be connected to other combustion devices (secondary sources) to reduce the carbon dioxide emissions of these other combustion devices by allowing combustion gases from the secondary source to be passed through the elongated metal member 70.
Downstream of apparatus 10, carbon monoxide gas (along with any remaining carbon dioxide gas) may be separated from the nitrogen gas. The nitrogen gas may be released to atmosphere. A Fisher-Tropsch chemical process can be used to convert gaseous carbon monoxide and hydrogen into liquid hydrocarbons.
In this document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A
reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.
As can be understood, the examples described above and illustrated are intended to be exemplary only.
The embodiments described in this document provide non-limiting examples of possible implementations of the present technology. Upon review of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made to the embodiments described herein without departing from the scope of the present technology.
Modifications could be Date Recue/Date Received 2022-03-25 implemented by a person of ordinary skill in the art in view of the present disclosure, which modifications would be within the scope of the present technology.
The scope of the claims should not be limited by the illustrated embodiments set forth as examples, but should be given the broadest interpretation consistent with a purposive construction of the claims in view of the description as a whole.

Date Recue/Date Received 2022-03-25

Claims (14)

1. WHAT IS CLAIMED IS:
   I. A method for reducing carbon dioxide emissions, comprising:
   surrounding a combustion source with a molecular sieve, the molecular sieve having an inner surface and an outer surface, the inner surface facing the combustion source and defining an inner flow passage;
   surrounding the molecular sieve with a body, the body having a peripheral sidewall having an inner surface facing the outer surface of the molecular sieve and defining an outer flow passage;
   raising a temperature of a mixture of combustion gases containing Carbon Dioxide (CO2), passing the mixture of gases along the outer flow passage exposed to the outer surface of the metal oxide framework coated molecular sieve;
   catalytically reducing the carbon dioxide to CO by iron forming iron oxide within the pores of the metal oxide forming free carbon;
   increasing free oxygen liberated from iron oxide reduced by carbon monoxide within the metal oxide framework; and forming carbon monoxide by oxidizing free carbon with free oxygen.
2. 2. The method of claim 1, wherein an elongated metal member is positioned in the inner flow passage and a helical flow is induced through the elongated metal member.
3. 3. The method of claim 2, wherein the elongated metal member is tubular and combustion gases from a secondary source are passed along the elongated metal member for processing.
4. 4. The method of claim 1, wherein conducted ultrasound is used to monitor a conversion of CO2 to CO based upon a difference in relative densities of CO2 and CO.
5. 5. An apparatus for reducing carbon dioxide emissions, comprising:
   a tubular body having a first end, a second end and a peripheral sidewall having an inner surface that defines a central bore and an outer surface;
   an electrical control assembly for connecting the tubular body to a power source for purposes of selectively supplying an electrical current to cause the tubular body to function as a semi-conductor;
   a porous tubular molecular sieve positioned concentrically within central bore of the tubular body, the porous tubular molecular sieve having a first end, a second end and a circumferential wall having an inner surface and an outer surface, the inner surface defines an inner flow passage and the outer surface forms an outer flow passage with the inner surface of the peripheral sidewall of the tubular body;
   a first transition connection where the inner flow passage connects to the outer flow passage;
   a burner input connection being positioned at a first end of the inner flow passage;
   and an outlet for processed combustion gases.
6. 6. The apparatus of claim 5, wherein an outer housing is provided, the outer housing having a first end, a second end and a peripheral sidewall that defines a housing cavity;
   the outer surface of the tubular body forming an outermost flow passage with the peripheral sidewall of the outer housing; and a second transition connection being provided where the outer flow passage connects to the outennost flow passage.
7. 7. The apparatus of claim 5, wherein an elongated metal member is concentrically positioned within the inner flow passage of the porous tubular molecular sieve, the elongated metal member having a first end and a second end.
8. 8. The apparatus of claim 7, wherein the elongated metal member is tubular.
9. 9. The apparatus of claim 6, wherein a flow restriction is positioned at the second transition connection.
10. 10. The apparatus of claim 9, wherein a conducted ultrasound transducer is in communication with the outer flow passage at the flow restriction.
11. 11. The apparatus of claim 9, wherein a suction source is connected to the outermost flow passage for purposes of counteracting back pressure caused by the flow restriction.
12. 12. The apparatus of claim 5, wherein the tubular body is a non-porous conductive ceramic.
13. 13. The apparatus of claim 5, wherein the porous tubular molecular sieve is a porous non-conductive ceramic.
14. 14. An apparatus for reducing carbon dioxide emissions, comprising:
    an outer housing having a first end, a second end and a peripheral sidewall that defines a housing cavity;
    a tubular body of non-porous conductive ceramic positioned within the housing cavity of the outer housing, the tubular body having a first end, a second end and a peripheral sidewall having an inner surface and an outer surface, the inner surface defines a central bore, and the outer surface defines an outermost flow passage with the peripheral sidewall of the outer housing;
    
    an electrical control assembly for connecting the tubular body to a power source for purposes of selectively supplying an electrical current to cause the tubular body to function as a semi-conductor;
    a porous tubular molecular sieve of porous non-conductive ceramic positioned concentrically within central bore of the tubular body, the porous tubular molecular sieve having a first end, a second end and a circumferential wall having an inner surface and an outer surface, the inner surface defines an inner flow passage and the outer surface forms an outer flow passage with the inner surface of the peripheral sidewall of the tubular body;
    an elongated tubular metal member concentrically positioned within the inner flow passage of the porous tubular molecular sieve, the elongated tubular metal member having a first end and a second end;
    a first transition connection where the inner flow passage connects to the outer flow passage, the second end of the elongated tubular metal member terminating at the first transition connection;
    a second transition connection where the outer flow passage connects to the outermost flow passage, a flow restriction is positioned at the second transition connection;
    a conducted ultrasound transducer in communication with the outer flow passage at the flow restriction;
    a suction source connected to the outermost flow passage for purposes of counteracting back pressure caused by the flow restriction;
    a burner input connection being positioned at the first end of the inner flow passage; and an outlet for processed combustion gases in flow communication with the outermost flow passage.