EP3614084A1 - Procédé et installation cryogéniques de séparation d'air - Google Patents

Procédé et installation cryogéniques de séparation d'air Download PDF

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Publication number
EP3614084A1
EP3614084A1 EP18020401.8A EP18020401A EP3614084A1 EP 3614084 A1 EP3614084 A1 EP 3614084A1 EP 18020401 A EP18020401 A EP 18020401A EP 3614084 A1 EP3614084 A1 EP 3614084A1
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EP
European Patent Office
Prior art keywords
separation unit
separation
air
argon
unit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Application number
EP18020401.8A
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German (de)
English (en)
Inventor
Stefan Lochner
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Linde GmbH
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Linde GmbH
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Filing date
Publication date
Application filed by Linde GmbH filed Critical Linde GmbH
Priority to EP18020401.8A priority Critical patent/EP3614084A1/fr
Priority to CN201980048335.1A priority patent/CN112437862B/zh
Priority to PCT/EP2019/025276 priority patent/WO2020038607A2/fr
Priority to US17/269,121 priority patent/US11976880B2/en
Publication of EP3614084A1 publication Critical patent/EP3614084A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04642—Recovering noble gases from air
    • F25J3/04648—Recovering noble gases from air argon
    • F25J3/04654—Producing crude argon in a crude argon column
    • F25J3/04666—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system
    • F25J3/04672—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system having a top condenser
    • F25J3/04678—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system having a top condenser cooled by oxygen enriched liquid from high pressure column bottoms
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04006—Providing pressurised feed air or process streams within or from the air fractionation unit
    • F25J3/04078—Providing pressurised feed air or process streams within or from the air fractionation unit providing pressurized products by liquid compression and vaporisation with cold recovery, i.e. so-called internal compression
    • F25J3/0409—Providing pressurised feed air or process streams within or from the air fractionation unit providing pressurized products by liquid compression and vaporisation with cold recovery, i.e. so-called internal compression of oxygen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04406—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system
    • F25J3/04412—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system in a classical double column flowsheet, i.e. with thermal coupling by a main reboiler-condenser in the bottom of low pressure respectively top of high pressure column
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04866—Construction and layout of air fractionation equipments, e.g. valves, machines
    • F25J3/04872—Vertical layout of cold equipments within in the cold box, e.g. columns, heat exchangers etc.
    • F25J3/04878—Side by side arrangement of multiple vessels in a main column system, wherein the vessels are normally mounted one upon the other or forming different sections of the same column
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04866—Construction and layout of air fractionation equipments, e.g. valves, machines
    • F25J3/0489—Modularity and arrangement of parts of the air fractionation unit, in particular of the cold box, e.g. pre-fabrication, assembling and erection, dimensions, horizontal layout "plot"

Definitions

  • the invention relates to a method for the low-temperature separation of air and a corresponding system according to the preambles of the independent claims.
  • Air separation plants have distillation column systems which can be designed, for example, as two-column systems, in particular as classic Linde double-column systems, but also as three- or multi-column systems.
  • distillation columns for the production of nitrogen and / or oxygen in the liquid and / or gaseous state that is to say the distillation columns for the nitrogen-oxygen separation
  • distillation columns for the production of further air components in particular the noble gases krypton, xenon and / or argon, can be provided.
  • the distillation columns of the above-mentioned distillation column systems are operated at different pressure levels.
  • Known double column systems have a so-called high pressure column (also referred to as a pressure column, medium pressure column or lower column) and a so-called low pressure column (also referred to as an upper column).
  • the high-pressure column is typically operated at a pressure level of 4 to 7 bar, in particular approximately 5.3 bar.
  • the low pressure column is operated at a pressure level of typically 1 to 2 bar, in particular approximately 1.4 bar. In certain cases, higher pressure levels can also be used in the low pressure column.
  • the pressures specified here and below are absolute pressures at the top of the columns specified.
  • the present invention is based on a method or a corresponding system in which a high and a low pressure column is used.
  • the low-pressure column is not formed in one piece, but is divided into a first section and a second section, the first and the second section being arranged at different positions of the air separation plant and at different heights, and in particular not in a plan view of a longitudinal column axis project onto each other.
  • the first and the second section of the low pressure column are operated at a common pressure level within the scope of the present invention.
  • the low-pressure column used in the context of the present invention differs from also known arrangements, in which, in addition to the high-pressure and low-pressure column, a further column for separating nitrogen and oxygen is provided, which, however, is operated at a pressure level, that lies between the pressure levels at which the high pressure column and the low pressure column are operated.
  • Air separation plants with raw and pure argon columns can be used to obtain argon.
  • An example is illustrated by Häring (see above) in Figure 2.3A and described from page 26 in the section "Rectification in the Low-pressure, Crude and Pure Argon Column” and from page 29 in the section "Cryogenic Production of Pure Argon".
  • argon accumulates at a certain height in the low-pressure column in corresponding plants.
  • argon-enriched gas with an argon concentration of typically 5 to 15 mol percent can be withdrawn from the low-pressure column and transferred to the crude argon column.
  • a corresponding gas typically contains approx. 100 ppm nitrogen and otherwise essentially oxygen.
  • the crude argon column essentially serves to separate the oxygen from the gas drawn off from the low-pressure column.
  • the separated oxygen in the crude argon column or a corresponding oxygen-rich fluid can be returned to the low-pressure column in liquid form.
  • the oxygen or the oxygen-rich fluid is typically fed into the low-pressure column several theoretical or practical trays below the feed point for the liquid which has been drawn off from the high-pressure column, enriched with oxygen and depleted with nitrogen and possibly partially or completely evaporated.
  • a gaseous fraction which remains in the crude argon column and essentially contains argon and nitrogen is separated further in the pure argon column to obtain pure argon.
  • a pure argon column can also be dispensed with in corresponding systems, it being typically ensured here that the nitrogen content at the argon transition is below 1 ppm.
  • argon of the same quality as from a conventional pure argon column is drawn off from the raw argon column somewhat below the fluid conventionally transferred into the pure argon column, the bottoms in the section between the raw argon condenser, i.e. the top condenser of the raw argon column, and a corresponding deduction as barrier bottoms for Serve nitrogen.
  • argon although contained in atmospheric air with a content of less than 1 mole percent, has a strong influence on the concentration profile in the low pressure column.
  • the separation in the lowest separation section of the low pressure column which typically comprises 30 to 40 theoretical or practical trays, can be regarded as an essentially binary separation between oxygen and argon. Only from the exit point for the gas transferred to the crude argon column does the separation within a few theoretical or practical soils change into a ternary separation of nitrogen, oxygen and argon.
  • argon-enriched gas is transferred from the low-pressure column to the crude argon column, but essentially only the oxygen contained in this gas is returned to the low-pressure column.
  • the argon discharged with a correspondingly removed gas is permanently withdrawn from the low pressure column.
  • the advantageous effect of the argon discharge is due to the fact that the separation of oxygen and argon is no longer necessary for the amount of argon discharged in the low pressure column, but this binary separation can be outsourced from the low pressure column.
  • the separation of oxygen and argon in the low-pressure column itself is fundamentally complex and requires a corresponding "heating" performance of the main condenser.
  • the heating capacity of the main condenser can be reduced. Therefore, with a constant yield of oxygen, for example, either more air can be blown into the low-pressure column or more pressurized nitrogen can be removed from the high-pressure column, which in turn can offer energetic advantages.
  • an argon discharge column can be understood here as a separation column for the separation of oxygen and argon, which is not used to obtain a pure argon product, but essentially serves to discharge argon from the low pressure column.
  • an argon discharge column differs only slightly from that of a classic crude argon column.
  • an argon discharge column typically contains significantly fewer theoretical or practical trays, namely less than 40, in particular between 15 and 30.
  • the bottom area of an argon discharge column can be connected to an intermediate point of the low-pressure column.
  • An argon discharge column can in particular be cooled by means of a top condenser in which the liquid drawn off from the high-pressure column, oxygen-enriched and nitrogen-depleted, is partially evaporated.
  • An argon discharge column typically does not have a bottom evaporator.
  • the present invention uses an argon purge column.
  • the object of the present invention is to improve the low-temperature separation of air using argon discharge columns and in particular to make the arrangement of the distillation columns used more advantageous.
  • the present invention proposes a method for the low-temperature separation of air and a corresponding system with the features of the respective independent claims. Refinements are the subject of the dependent claims and the following description.
  • Liquids and gases can, in the language used here, be rich or poor in one or more components, “rich” for a content of at least 50%, 75%, 90%, 95%, 99%, 99.5%, 99, 9% or 99.99% and “poor” for a maximum of 50%, 25%, 10%, 5%, 1%, 0.1% or 0.01% on a mole, weight or volume basis ,
  • the term “predominantly” can correspond to the definition of "rich”.
  • Liquids and gases can also be enriched or depleted in one or more components, these terms refer to a content in a starting liquid or gas from which the liquid or gas was obtained.
  • the liquid or gas is "enriched” if it contains at least 1.1 times, 1.5 times, 2 times, 5 times, 10 times 100 times or 1,000 times the content, and " depleted "if this or this contains at most 0.9 times, 0.5 times, 0.1 times, 0.01 times or 0.001 times the content of a corresponding component, based on the starting liquid or the starting gas. If, for example, “oxygen”, “nitrogen” or “argon” is mentioned here, this should also be understood to mean a liquid or a gas which is rich in oxygen or nitrogen, but does not necessarily have to consist exclusively of it.
  • pressure level and “temperature level” to characterize pressures and temperatures, which is intended to express that corresponding pressures and temperatures in a corresponding system do not have to be used in the form of exact pressure or temperature values to realize the inventive concept.
  • pressures and temperatures are typically in certain ranges, for example ⁇ 1%, 5%, 10%, 20% or even 50% around an average.
  • Corresponding pressure levels and temperature levels can lie in disjoint areas or in areas that overlap one another.
  • pressure levels include, for example, unavoidable or expected pressure drops.
  • the pressure levels given here in bar are absolute pressures.
  • the high-pressure column and the low-pressure column (or, in the context of the present invention, its first section) of an air separation plant are in heat-exchanging connection via a so-called main condenser.
  • the Main condenser can in particular be arranged in a lower (sump) area of the low-pressure column (or its first section thereof). In this case, it is a so-called internal main condenser and the evaporation space of the main condenser is also the interior of the low-pressure column (or of its first section).
  • the main condenser can basically be arranged outside the interior of the high-pressure column, that is to say a so-called external main condenser.
  • Evaporation and liquefaction space are formed by groups of passages that are in heat exchange relationship with each other.
  • the main condenser can in particular be used as a single or multi-storey bath evaporator, in particular as a cascade evaporator (such as in the EP 1 287 302 B1 described), or be designed as a falling film evaporator. It can be formed by a single heat exchanger block or by a plurality of heat exchanger blocks which are arranged in a common pressure vessel.
  • the present invention is expressly not limited to corresponding types of condenser evaporators or capacitors.
  • a "main heat exchanger" of an air separation plant is used to cool the feed air in indirect heat exchange with return flows from the distillation column system. It can be formed from a single or a plurality of heat exchanger sections connected in parallel and / or in series, for example from one or more plate heat exchanger blocks. Separate heat exchangers, which are used specifically for the evaporation or pseudo-evaporation of a single liquid or supercritical fluid, without heating and / or evaporation of another fluid, are not part of the main heat exchanger.
  • a “subcooler” or “subcooling counterflow” is a heat exchanger used here, through which gaseous and liquid material flows in an air separation plant are subjected to heat exchange, which is taken from the rectification column system and partially or completely returned to the rectification column system after the heat exchange.
  • the present invention is based on the knowledge that an arrangement of an argon discharge column in a distillation column system of an air separation plant, which has a two-part low-pressure column, which is significantly different from the state of the art, allows an air separation process to be designed particularly efficiently and, in particular, a corresponding air separation plant can be produced particularly simply and inexpensively.
  • the advantages achievable within the scope of the present invention include, in particular, a particularly advantageous arrangement of the respective components of a distillation column system proposed according to the invention in different cold boxes, which, even when argon discharge columns are used, enables them to be prefabricated and transported to the respective place of use in a prefabricated manner.
  • the advantages of the present invention are not limited to the improved arrangement and transportability of the components in cold boxes, but in particular also include a simple construction of a corresponding air separation plant by dispensing with extensive piping, as is typically required in the case of a different, conventional arrangement of an argon discharge column.
  • An essential aspect of the present invention in addition to the already mentioned division of the low-pressure column, is to place an argon discharge column in the open state on the underside of the lower section of a corresponding two-part low-pressure column.
  • the “lower” or “first” section of a two-part low-pressure column is understood to mean the section in the sump of which, as in the sump of a conventional one-piece low-pressure column, an oxygen-rich liquid is formed.
  • the lower or first section of a corresponding two-part low-pressure column is in particular connected to the high-pressure column as a structural unit.
  • a correspondingly created structural unit can be introduced, in particular, into a still portable cold box, so a corresponding air separation unit is prefabricated and, if necessary, a corresponding cold box can be brought to the respective place of use.
  • the remaining components in the cold part of the air separation plant, i.e. in particular the second section of the low-pressure column and possibly a subcooling counterflow can be outsourced to at least one second cold box, which likewise typically does not exceed the maximum sizes for any transport to the place of use.
  • a particularly advantageous embodiment of the present invention results if the second section of the low-pressure column is moved into a cold box and the lines used for the piping of the separation units mentioned, in particular together with a subcooler, are moved to another cold box.
  • the present invention proposes a method for cryogenic air separation using an air separation plant with a distillation column system.
  • the distillation column system comprises a first separation unit (corresponding to the high-pressure column of a conventional air separation plant), a second separation unit (corresponding to the first or lower section of a two-part low-pressure column), a third separation unit (corresponding to the argon discharge column) and a fourth separation unit (corresponding to the second or upper section of a two-part low-pressure column).
  • Compressed and cooled air is fed into the first separation unit, but not necessarily only into this, within the scope of the present invention.
  • Corresponding air can be compressed using known measures, in particular using a main air compressor and possibly one or more secondary compressors, boosters and the like.
  • the first separation unit is operated at a first pressure level of 4 to 8 bar absolute pressure, for example a pressure level of approximately 5.3 bar absolute pressure, which corresponds to the normal operating pressure of a high-pressure column of an air separation plant.
  • the second, the third and the fourth separation unit are operated in the context of the present invention at a common second pressure level, which in the context of the present invention is 1 to 2 bar absolute pressure, that is to say corresponds to the typical pressure level of a low-pressure column of an air separation plant.
  • the second pressure level can be, for example, approximately 1.4 bar absolute pressure.
  • the first separation unit forms an oxygen-enriched and nitrogen-depleted, argon-containing first bottoms liquid and a nitrogen-enriched and oxygen-depleted first overhead gas.
  • the relevant specialist literature on air separation or the operation of high-pressure columns of known air separation plants.
  • the present invention is not restricted to liquefying only the portion of the first overhead gas which is attributed to the first separation unit. Rather, within the scope of the present invention, further overhead gas can also be liquefied and, in particular as a liquid air product, without or with subsequent evaporation or conversion into the supercritical state, can be discharged as a product from the air separation plant. Furthermore, in the context of the present invention, further liquefied overhead gas from the top of the first separation unit, that is to say liquefied first overhead gas, can be fed in as a return to the fourth separation unit, in particular after corresponding liquefied overhead gas has previously been passed through a supercooling counterflow.
  • Non-liquefied overhead gas can also be drawn off from the top of the first separation unit and, for example as a pressurized nitrogen product, can be carried out from the air separation plant.
  • a pressurized nitrogen product can be carried out from the air separation plant.
  • the use of an argon discharge column can in particular achieve that the amount of top gas of the high pressure column discharged from the air separation plant can be increased accordingly.
  • an oxygen-rich second bottom liquid and a second top gas enriched in argon are formed by means of the second separation unit.
  • the second separation unit in the context of the present invention essentially corresponds to the lower section or first section of a two-part low-pressure column or the lower part of a classic, one-part low-pressure column up to the argon maximum. As already mentioned, this is achieved by the choice of appropriate release agents or the selection of the number of partitions.
  • a corresponding design of the second separation unit enables advantageous argon removal in the third separation unit.
  • a second portion of the second overhead gas is transferred to the third separation unit and a second portion to the fourth separation unit.
  • the fourth separation unit the conventional second or upper Section corresponds to a two-part low-pressure column
  • the third separation unit is essentially intended to carry out an argon discharge.
  • the third separation unit is designed as a structural unit together with the second separation unit within the scope of the present invention. It is therefore not necessary to remove the corresponding fluid from the low-pressure column and to transfer it to an argon discharge column.
  • the second overhead gas is in particular transferred to the third separation unit without deflection. The transfer takes place in particular without a wire.
  • the third separation unit has separation zones which can be formed using known separation devices, in particular ordered or disordered packings or trays.
  • the third separation unit can be designed in a known manner, the third separation unit corresponding to an argon discharge column, which, however, is open in the lower area opposite the second separation unit.
  • a fourth bottom liquid and a fourth top gas are formed by means of the fourth separation unit and the fourth bottom liquid is partly or completely returned to the second separation unit.
  • a suitable pump is used for the transfer of the fourth bottom liquid to the second separation unit.
  • the second separation unit that is to say the first or lower section of the low-pressure column, has 10 to 50 theoretical plates, in particular 20 to 40 theoretical plates, and that the third separation unit 10 to 60 theoretical plates, in particular 15 to 30 theoretical plates.
  • the second separation unit is therefore the section of a low-pressure column which comprises the typical oxygen section or corresponding separation devices of such an oxygen section.
  • the the third separation unit is, as already explained several times, as an argon discharge column.
  • the third separation unit can have a smaller cross section than the second separation unit, and the entire cross section of the third separation unit can be available for an inflow of the first portion of the second top gas into the third separation unit.
  • an argon discharge column is arranged next to the distillation column system formed from high and low pressure column
  • no transfer of corresponding fluids by means of pumps, lines and the like is required in the context of the present invention.
  • second overhead gas can rise from the second separation unit to the third separation unit essentially unimpeded, in particular without deflection or line, and liquid from the third separation unit can flow into the second separation unit essentially unhindered.
  • the argon discharge column used in the context of the present invention can also have a top condenser which can be cooled with oxygen-enriched liquid from the high pressure column, in this case the first sump liquid.
  • Corresponding liquid, which is partially evaporated during cooling, can then be fed into the fourth separation unit, in particular at different heights.
  • the corresponding currents are advantageously divided outside the top capacitor so that they have different concentrations.
  • main capacitors i.e. capacitors that connect the first separation unit and the second separation unit in a heat-exchanging manner, in particular falling film or cascade evaporators, in particular multi-storey cascade evaporators of the type explained above, can be used.
  • the present invention is expressly not limited to such forms of condenser evaporators, but can be used with any type of main condenser.
  • the compressed and cooled air which is fed into the first separation unit can in particular comprise a gaseous and a liquefied feed air stream, which are each fed into the first separation unit at the first pressure level.
  • a gaseous feed air stream at a first feed position and a liquid feed air stream at a second feed position can be fed into the first separation unit, the first feed position being below the second feed position, with no separation devices typically being provided in the first separation unit below the first feed position, whereby the second feed position is advantageously above a liquid retention device from which a liquid stream can be withdrawn from the first separation unit, and the second feed position lies above a separation unit or a separation area of the first separation device.
  • feed air can also be fed into the first separation unit, for example in two phases, in a common line. The formation of appropriate material flows is known in the field of air separation.
  • the first separating unit and the second separating unit are structurally connected to one another with particular advantage and can be arranged within a common column casing, the common column casing also being structurally connected to the third separating unit.
  • a common column jacket in the sense of the present invention can in particular be a common cylindrical outer container, so that the first separating unit and the second separating unit can be produced with the same cross section within the scope of the present invention.
  • the fourth separation unit can also have a smaller, but also a larger cross-section than the second separation unit. It can in particular have 18 to 65 theoretical plates and thus correspond to the rest of a corresponding two-part low-pressure column, the first section of which is formed by the second separation unit.
  • the first portion of the second top gas has in particular 20 to 50 percent by volume and the second portion of the second top gas has 50 to 80 percent by volume (ie in particular the rest) of the second top gas.
  • the fourth separation unit can be arranged in particular next to the second separation unit and in particular in a separate cold box. In this way, the overall height of a corresponding air separation plant is reduced overall.
  • the fourth bottom liquid is returned to the second separation unit using a transfer pump or at least two transfer pumps arranged in parallel, and in particular at the top of the second separation unit to the second separation unit as liquid return is given up.
  • two pumps can be operated in parallel and a third can be provided for reasons of redundancy.
  • the use of two transfer pumps arranged in parallel enables a particularly simple construction because pumps of corresponding sizes are available as standard.
  • a corresponding transfer pump is provided in order to overcome the height difference between the second separation unit and the fourth separation unit or vice versa.
  • the second portion of the second top gas can advantageously flow into the fourth separation unit through a minimal pressure difference between the second separation unit and the fourth separation unit.
  • the first separation unit, the second separation unit and the third separation unit are advantageously arranged in a common cold box and the fourth separation unit is arranged in a further cold box.
  • the first sump liquid regardless of whether it is arranged in a further cold box or not, is first passed through a corresponding countercooling counterflow and then fed into the fourth separation unit at a first feed position. It can further be provided to draw a liquid stream from the first separation unit in the vicinity, preferably directly below the feed position of a liquid feed air stream into the first separation unit, to lead it through the supercooling counterflow, and to feed it into the fourth separation unit at a second feed position.
  • the second feed position in the fourth separation unit is advantageously above the first feed position in the fourth separation unit and is advantageously separated from the latter by at least one separation section.
  • a liquid air product in particular can be removed from the distillation column system, increased in pressure in the liquid state, converted into the gaseous or supercritical state by heating, and discharged from the air separation plant.
  • the present invention can therefore be used in particular in connection with a so-called internal compression of air products.
  • internal compression methods reference is made to the cited prior art.
  • the invention also extends to an air separation plant with a distillation column system which comprises a first separation unit, a second separation unit, a third separation unit and a fourth separation unit, as stated in the corresponding independent claim.
  • FIG. 1 shows a distillation column system of an air separation plant, which is set up for an operation according to an embodiment of the present invention, in a greatly simplified partial view.
  • the distillation column system illustrated is designated 100 in total. It is provided in an air separation plant 200, which is only indicated here.
  • Illustrated components of the distillation column system 100 include a first separation unit 110, a second separation unit 120, a third separation unit 130 and a fourth separation unit 140, a main condenser 150, a supercooling counterflow 160, a transfer pump 170, an internal compression pump 180 and a top condenser 190.
  • the first separation unit 110 corresponds to a high-pressure column of a conventional air separation plant.
  • the first separation unit is operated at a corresponding pressure level, referred to here as the "first pressure level”.
  • the second separation unit 120 and the fourth separation unit 140 correspond to a first section and a second section of a low pressure column of a conventional air separation plant. You will be on an appropriate joint Pressure level, here referred to as "second pressure level" operated.
  • the third separation unit 130 represents an argon discharge column. It is also operated at the second pressure level.
  • the first separation unit 110 and the second separation unit 120 are in heat-exchanging connection via the main condenser 150, as will also be explained below.
  • the first separating unit 110 and the second separating unit 120 are furthermore arranged, in particular within a common column casing and above one another, in particular directly above one another, in the sense explained above.
  • the top capacitor 190 is arranged at the upper end of the third separation unit 130.
  • an air separation plant of which the distillation column system 110 can be part
  • relevant specialist literature for example Haring (see above), in particular chapter 2.2.5 and figure 2.3A.
  • a gaseous feed air stream 1 and a liquefied feed air stream 2 can be provided.
  • a main air compressor, cleaning and processing devices, turbines, expansion valves and a main heat exchanger of a known type can be used.
  • the feed air streams 1 and 2 are fed into the first separation unit 110 at feed positions 111 and 112, respectively.
  • an oxygen-enriched and nitrogen-depleted and argon-containing bottoms liquid and a nitrogen-enriched and oxygen-depleted top gas are formed at the first pressure level.
  • the bottom liquid is drawn off from the first separation unit 110 in the form of a stream 3.
  • the top gas is drawn off from the first separation unit 110 in the form of a stream 4.
  • Liquid in the form of a material flow 5 from the first separation unit 110 is carried out directly below the feed position 112 for the feed air flow 2.
  • the material flow 3 is passed through the supercooling counterflow 160 and partly fed into the fourth separation unit 140 in the form of a material flow 31 at a feed position 141. Another part is transferred in the form of a material flow 32 into an evaporation space of the top condenser 190. From the Evaporation space of the top condenser 190, a liquid stream 33 and a gaseous stream 34 are drawn off and likewise fed into the fourth separation unit 140, in particular at different heights.
  • the stream 4 is also divided into two sub-streams 41 and 42.
  • the first partial flow 41 is partially or completely liquefied in the main condenser 150. A first portion 411 of the first partial flow 41 is fed back to the first separation unit 110 at a feed position 113 as a return.
  • a second portion 412 of the first partial flow 41 is passed through the supercooling counterflow 160 and is fed as return to the fourth separation unit 140.
  • the partial stream 42 is carried out as a gaseous nitrogen pressure product from the distillation column system 100.
  • the material flow 5 is passed through the supercooling counterflow 160 and fed into the fourth separation unit 140 at a feed position 142.
  • an oxygen-rich bottom liquid and an overhead gas enriched with argon are formed in the second separation unit 120.
  • the bottom liquid is drawn off from the second separation unit 120 in the form of a stream 6.
  • a first partial flow 61 of the material flow 6 is increased in pressure in the internal compression pump 180 in the liquid state, and is converted into the gaseous or supercritical state by heating (in FIG Figure 1 not separately illustrated) and designed as an internally compressed oxygen pressure product.
  • a second partial flow 62 of the material flow 6 is provided as a liquid oxygen product after partial passage through the supercooling counterflow 160 and corresponding tempering.
  • the top gas of the second separation unit 120 partly rises into the third separation unit 130, which is arranged above the second separation unit 120 and which opens in a lower region, in particular without a cross-sectional taper to the second separation unit 120. Another part of the top gas is drawn off in the form of a stream 7. The material flow 7 is fed into a lower region of the fourth separation unit 140 at a feed position 143.
  • a top gas is formed in the third separation unit 130, which contains at least the major part of the argon that was previously contained in the feed air supplied to the distillation column system 100.
  • This overhead gas from the third separation unit 130 is drawn off in the form of a stream 8.
  • Liquid trickling down from the third separation unit 130, which in this way is at argon is depleted or (essentially) free of argon, is returned directly to the second separation unit 120. In the third separation unit 130, argon is thus removed.
  • a sump liquid and a top gas are formed in the fourth separation unit 140.
  • the bottom liquid is drawn off from the fourth separation unit 140 in the form of a material flow 9 and is returned as return to the second separation unit 120 by means of the transfer pump 170 and is thereby fed into the second separation unit 120 at a feed position 114.
  • a material stream 10, so-called impure nitrogen is removed from the fourth separation unit, passed through the supercooling counterflow 160 and carried out from the distillation column system 100.
  • a nitrogen-rich stream 11 which is provided as a gaseous low-pressure nitrogen product.
  • Nitrogen-rich liquid in the form of a material flow 12 is drawn off from a liquid retention device at the head of the fourth separation unit (140) and made available as a liquid nitrogen product. If no gaseous low-pressure nitrogen product is required, a corresponding separation section in the fourth separation unit 14 can be omitted and all overhead gas can be drawn off as impure nitrogen in accordance with the material flow 10.
  • the first separation unit 110, the second separation unit 120 and the third separation unit 130, on the one hand, and the fourth separation unit 140, on the other hand are each provided in a cold box A or B and with one another and / or with others Devices such as the supercooling counterflow 160 and the main heat exchanger (not shown) are connected to one another by means of lines or piping, here combined with 20.
  • the piping runs vertically, at least in sections. At least part of such piping 20 can be arranged separately from the two cold boxes A and B, in which the first separating unit 110, the second separating unit 120 and the third separating unit 130 on the one hand and the fourth separating unit 140 on the other hand, are arranged in an additional cold box C.
  • This additional cold box C for piping can also contain subcooler 160 in particular.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Emergency Medicine (AREA)
  • Separation By Low-Temperature Treatments (AREA)
EP18020401.8A 2018-08-22 2018-08-22 Procédé et installation cryogéniques de séparation d'air Withdrawn EP3614084A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP18020401.8A EP3614084A1 (fr) 2018-08-22 2018-08-22 Procédé et installation cryogéniques de séparation d'air
CN201980048335.1A CN112437862B (zh) 2018-08-22 2019-08-20 用于低温分离空气的方法和设备
PCT/EP2019/025276 WO2020038607A2 (fr) 2018-08-22 2019-08-20 Procédé et installation de séparation d'air à basse température
US17/269,121 US11976880B2 (en) 2018-08-22 2019-08-20 Method and installation for low temperature separation of air

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EP18020401.8A EP3614084A1 (fr) 2018-08-22 2018-08-22 Procédé et installation cryogéniques de séparation d'air

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5311744A (en) * 1992-12-16 1994-05-17 The Boc Group, Inc. Cryogenic air separation process and apparatus
US5339648A (en) * 1993-08-05 1994-08-23 Praxair Technology, Inc. Distillation system with partitioned column
FR2739438A1 (fr) * 1995-09-29 1997-04-04 Air Liquide Procede et installation de production d'argon par distillation cryogenique
EP1287302B1 (fr) 2000-05-31 2005-09-21 Linde AG Condenseur a bain a plusieurs etages
US20150096327A1 (en) * 2012-04-27 2015-04-09 Linde Aktiengesellschaft Transportable package having a cold box, low-temperature air separation plant and method for producing a low-temperature air separation plant
WO2016146246A1 (fr) * 2015-03-13 2016-09-22 Linde Aktiengesellschaft Système permettant de produire de l'oxygène par fractionnement d'air à basse température

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1095155A (zh) * 1993-12-16 1994-11-16 波克股份有限公司 空气深冷分离的方法和设备
FR2761897B1 (fr) 1997-04-11 1999-05-14 Air Liquide Installation de separation d'un melange gazeux par distillation
CA2900122C (fr) 2013-03-06 2023-10-31 Linde Aktiengesellschaft Installation de separation d'air, procede de recuperation d'un produit contenant de l'argon et procede pour creer une installation de separation d'air

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5311744A (en) * 1992-12-16 1994-05-17 The Boc Group, Inc. Cryogenic air separation process and apparatus
US5339648A (en) * 1993-08-05 1994-08-23 Praxair Technology, Inc. Distillation system with partitioned column
FR2739438A1 (fr) * 1995-09-29 1997-04-04 Air Liquide Procede et installation de production d'argon par distillation cryogenique
EP1287302B1 (fr) 2000-05-31 2005-09-21 Linde AG Condenseur a bain a plusieurs etages
US20150096327A1 (en) * 2012-04-27 2015-04-09 Linde Aktiengesellschaft Transportable package having a cold box, low-temperature air separation plant and method for producing a low-temperature air separation plant
WO2016146246A1 (fr) * 2015-03-13 2016-09-22 Linde Aktiengesellschaft Système permettant de produire de l'oxygène par fractionnement d'air à basse température

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"Industrial Gases Processing", 2006, WILEY-VCH

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US11976880B2 (en) 2024-05-07
CN112437862A (zh) 2021-03-02
WO2020038607A2 (fr) 2020-02-27
WO2020038607A3 (fr) 2020-04-16
US20210325108A1 (en) 2021-10-21

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