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
  • F25J3/0204—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 characterised by the feed stream
  • F25J3/0223—H2/CO mixtures, i.e. synthesis gas; Water gas or shifted synthesis gas
• • 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
  • F25J3/0228—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 characterised by the separated product stream
  • F25J3/0233—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 characterised by the separated product stream separation of CnHm with 1 carbon atom or more
• • 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
  • F25J3/0228—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 characterised by the separated product stream
  • F25J3/0252—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 characterised by the separated product stream separation of hydrogen
• • 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
  • F25J3/0228—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 characterised by the separated product stream
  • F25J3/0257—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 characterised by the separated product stream separation of nitrogen
• • 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
  • F25J3/0228—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 characterised by the separated product stream
  • F25J3/0261—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 characterised by the separated product stream separation of carbon monoxide
• • 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
  • F25J2200/00—Processes or apparatus using separation by rectification
  • F25J2200/40—Features relating to the provision of boil-up in the bottom of a 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
  • F25J2200/00—Processes or apparatus using separation by rectification
  • F25J2200/50—Processes or apparatus using separation by rectification using multiple (re-)boiler-condensers at different heights of the 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
  • F25J2200/00—Processes or apparatus using separation by rectification
  • F25J2200/70—Refluxing the column with a condensed part of the feed stream, i.e. fractionator top is stripped or self-rectified
• • 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
  • F25J2200/00—Processes or apparatus using separation by rectification
  • F25J2200/74—Refluxing the column with at least a part of the partially condensed overhead gas
• • 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
  • F25J2200/00—Processes or apparatus using separation by rectification
  • F25J2200/76—Refluxing the column with condensed overhead gas being cycled in a quasi-closed loop refrigeration cycle
• • 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
  • F25J2205/00—Processes or apparatus using other separation and/or other processing means
  • F25J2205/02—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum
  • F25J2205/04—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum in the feed line, i.e. upstream of the fractionation step
• • 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
  • F25J2205/00—Processes or apparatus using other separation and/or other processing means
  • F25J2205/24—Processes or apparatus using other separation and/or other processing means using regenerators, cold accumulators or reversible heat exchangers
• • 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
  • F25J2205/00—Processes or apparatus using other separation and/or other processing means
  • F25J2205/30—Processes or apparatus using other separation and/or other processing means using a washing, e.g. "scrubbing" or bubble column for purification purposes
• • 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
  • F25J2235/00—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams
  • F25J2235/60—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams the fluid being (a mixture of) hydrocarbons
• • 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
  • F25J2270/00—Refrigeration techniques used
  • F25J2270/02—Internal refrigeration with liquid vaporising loop
• • 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
  • F25J2270/00—Refrigeration techniques used
  • F25J2270/04—Internal refrigeration with work-producing gas expansion loop
• • 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
  • F25J2270/00—Refrigeration techniques used
  • F25J2270/24—Quasi-closed internal or closed external carbon monoxide refrigeration cycle
• • 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
  • F25J2270/00—Refrigeration techniques used
  • F25J2270/88—Quasi-closed internal refrigeration or heat pump cycle, if not otherwise provided
• • 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
  • F25J2270/00—Refrigeration techniques used
  • F25J2270/90—External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration
  • F25J2270/902—Details about the refrigeration cycle used, e.g. composition of refrigerant, arrangement of compressors or cascade, make up sources, use of reflux exchangers etc.

Definitions

• the present invention relates to a method and an apparatus for separating a synthesis gas by cryogenic distillation.
• the synthesis gas contains as major components hydrogen, methane and carbon monoxide. It may also contain nitrogen.
• the first column carries out a methane wash in order to recover a fraction rich in CO and methane in the tank and at the top a fraction rich in hydrogen.
• the second column or column of exhaustion (called flash column in English) is used to evacuate the few percent of hydrogen contained in the liquid fraction of the first column.
• the present invention improves performance by using existing wash column equipment with intermediate gas cooling. Among the objects of the invention, it is desired:
• the idea of the invention is to cool and at least partially condense a gas withdrawn into an upper part of the exhaust column in an exchanger where at least one intermediate gas is cooled in the methane washing column and returning at least a portion of the at least partially condensed gas to the top of the exhaust column.
• the depletion column includes an upper portion and a lower portion, below the upper portion.
• the CO efficiency of about 0.5 to 1% can be increased compared to the case with the minaret.
• this overhead gas of the counter-current exhaustion column with another fluid of the cold box, for example liquid CO.
• a liquid CO capacity is installed at the top of the methane scrubbing column in order to operate at the temperature above the temperature. lowest possible. It would therefore be sufficient to add the gas from the exhaustion column into a heat exchanger for heating the liquid CO from the capacity in order to increase the CO recovery efficiency.
• This overhead gas from the exhaustion column represents only a fraction of the synthesis gas flow (2-3%), whereas the gas treated in normal time represents approximately the total flow of hydrogen, ie 70% of the flow rate. .
• the addition of this overhead column fluid in the heat exchanger is therefore marginal in terms of investment and improves performance.
• a process for separating a synthesis gas comprising hydrogen, carbon monoxide and methane and optionally nitrogen by cryogenic distillation in which: i) the gas of synthesis is purified and cooled to a cryogenic temperature,
• the cooled synthesis gas is separated by a first means to produce a hydrogen-depleted liquid
• the separation carried out by the first means is constituted by a washing step in a washing column with at least a part of the methane-enriched liquid withdrawn from a carbon monoxide and methane separation column having an overhead condenser, the condenser being cooled by a carbon monoxide cycle, and
• the hydrogen-depleted liquid is introduced into the upper part of a depletion column which also comprises a lower part, iv) a hydrogen-enriched gas is withdrawn at the top of the depletion column,
• a liquid is withdrawn in the tank from the exhaustion column and sent to the separation column, a carbon monoxide enriched and methanol-depleted gas is withdrawn at the top of the separation column, a liquid depleted in carbon monoxide and enriched in methane is withdrawn in the bottom of the separation column and the carbon monoxide enriched gas is heated by heat exchange with the synthesis gas of step i) to form a product, vi) a gas withdrawn into the upper part of the depletion column is at least partially condensed and returned at least in part to the upper part of the depletion column characterized in that the gas withdrawn in the upper part of the column at least partially condensed in a heat exchanger which also serves to cool at least one gas withdrawn from the washing column, the heat exchanger also serving to heat a refrigerant.
• the gas withdrawn at the top of the depletion column condenses against at least a portion of the carbon monoxide cycle liquid.
• the synthesis gas comprises nitrogen and the liquid withdrawn from the depletion column or a fluid derived from this liquid is separated in a denitrogenation column, the liquid of which serves to at least partially condense the overhead gas of the column exhaustion.
• the gas withdrawn into the upper part of the depletion column is at least partially condensed by heat exchange with a carbon monoxide enriched liquid withdrawn from the separating column which heats up and optionally vaporises at least partially.
• the liquid enriched in carbon monoxide is withdrawn from a distillation section of the separation column or from a capacity forming the head of the separation column.
• the gas withdrawn from the top of the depletion column is a top gas of the exhaust column withdrawn at a level above any means of heat transfer and mass of the exhaust column.
• the gas withdrawn from the upper part of the depletion column is withdrawn at least one theoretical plate below the head of the depletion column, a part of the methane-enriched liquid withdrawn from the separation column being sent to a level of the column of exhaustion above the level of withdrawal of the gas.
• the separation carried out by the first means does not include a washing step with a liquid enriched in methane.
• the process is kept cold by a cycle using the carbon monoxide enriched gas from the separation column.
• the hydrogen-depleted liquid contains between 1 and 3 mol% of hydrogen.
• the refrigerant is enriched in carbon monoxide
• the refrigerant is a liquid enriched in carbon monoxide, possibly from the separation column, which vaporizes in the second heat exchanger
• the second heat exchanger is heated only by means of the refrigerant.
• an apparatus for separating a synthesis gas comprising hydrogen, carbon monoxide, methane and optionally nitrogen by cryogenic distillation comprising a heat exchanger, a first separation means which is a methane washing column, a depletion column and optionally a carbon monoxide and methane separation column, means for purifying the synthesis gas, means for sending the purified gas to cooling in the heat exchanger to a cryogenic temperature, means for sending the cooled synthesis gas to the first means for producing a hydrogen-depleted liquid, means for introducing the hydrogen-depleted liquid into the upper part of the column of depletion which also comprises a lower part, means for withdrawing a hydrogen-enriched gas at the top of the depletion column, means for for withdrawing a liquid in the bottom of the exhaust column, a second heat exchanger, means for sending a gas withdrawn into the upper part of the exhaust column and means for sending at least a portion of the gas at least partially condensed in the second heat exchanger to
• the apparatus may also include:
• a denitrogenization column for separating the liquid withdrawn from the depletion column or a fluid derived from this liquid.
• means for withdrawing the carbon monoxide enriched liquid is from a distillation section of the separation column or from a capacity forming the top of the separation column.
• the cold holding means of the process comprise a cycle using the carbon monoxide enriched gas from the separation column.
• the second heat exchanger is an indirect heat exchanger.
• Figure 1 shows a process using a phase separator 9, a methane scrubbing column 15, a depletion column and a carbon monoxide and methane separation column 45, for example containing structured packings for the columns. and capable of operating at cryogenic temperatures.
• the synthesis gas 1 containing carbon monoxide, methane and carbon monoxide is purified with water and / or carbon dioxide in the purification unit 3 before arriving at the heat exchanger 7 where it cools to a cryogenic temperature and partially condenses.
• the two phases are separated in a phase separator 9 to form a hydrogen-enriched gas 11 and a hydrogen-depleted liquid 13.
• the gas 11 is sent to the bottom of the methane scrubber column which produces a gas enriched with hydrogen that heats up in the exchanger. Part of this gas 19 serves to regenerate the purification unit 3.
• At least one intermediate gas 21 A, 21 B, 21 C withdrawn from the column 15 is cooled in a heat exchanger 23 by indirect heat exchange with a process fluid, here the liquid 51.
• the tank liquid 17 of the column 15 joins the liquid 13 of the separator 9 and the mixture 91 containing between 1 and 3 mol% of hydrogen is sent to the top of a depletion column 25.
• a top gas 27 of the The exhaust column at least partially condenses in the heat exchanger 23. At least a portion 31 of the at least partially condensed gas is returned to the top of the depletion column 25 to provide reflux liquid.
• the remainder 29 can be heated in the heat exchanger 7 against the synthesis gas 5.
• the refrigerant gas 27 leaving to be cooled in the heat exchanger 23 undergoes at least partial condensation.
• partial condensation liquid and gas are created. It is possible that a portion of the liquid created passes through another pipe 31 or then falls through the pipe 27 from which the refrigerant gas to be cooled, to join the column 25. In this second case, the pipe 31 is not necessary .
• a liquid 33 taken in the bottom of the depletion column 25 cools in the exchange 7 and is sent to the separation column 45.
• Another part of the same liquid 35 vaporizes in a bottom reboiler 37 and is returned to the tank from the column of exhaustion.
• the separation column comprises a plurality of distillation separation sections and optionally a capacity 99. It has a bottom reboiler 73 which serves to heat the bottom liquid 75, the formed gas being returned to the vessel.
• the tank liquid 77 enriched with methane is divided in two. Part 83 vaporizes in exchanger 7 to form fuel.
• the remainder 85 is pressurized by a pump 87 and is sent to the top of the washing column 15.
• the overhead gas from the carbon monoxide enriched column 43 is fed to a product compressor 57 which produces a gas enriched with carbon monoxide 57.
• Part of the carbon monoxide enriched gas 61 is cooled and split in half.
• Part 65 is expanded in a turbine 67 to provide cold.
• the expanded gas 89 is returned to the inlet of the compressor 57.
• the remaining gas 69 continues to cool in the exchanger 7 and is used to heat the reboilers 73 and 37 (flow rates 93 and 73).
• the gas used for the reboiling is thus partially condensed and feeds as the flow 97 the capacity 99 at the top of the separation column 45.
• the gas 41 of the capacity 99 feeds the compressor 57.
• the liquid 47 of the capacity 99 is sent to a phase separator 49, the liquid 51 of the separator serves as a refrigerant in the heat exchanger 23 for cooling the intermediate gases 21 A, 21 B, 21 C and the overhead gas 27 of the depletion column.
• the liquid 51 is thus vaporized and returned to the phase separator 49 whose gas 53 supplies the compressor 57.
• a liquid withdrawn from the separation section of the separation column can replace the liquid 47 or other liquid of the process.
• the exhaustion column comprising a methane washing section, a part of the liquid 85 pressurized by the pump 87 being sent to the top of the depletion column 25 and another part being sent as for Figure 1 at the top of the washing column 15.
• the gas 27 withdrawn from the depletion column 25 is taken at least one theoretical plate below the head of the column.
• the at least partially condensed gas in the exchanger 23 returns to the exhaust column adjacent to the draw-off point and the rising gas in the upper part of the depletion column (washing section 25A) becomes more enriched in hydrogen, to reduce the number of theoretical plates required.
• the invention also applies to the case where the process does not use a methane scrubbing column.
• the first separation is carried out simply by partial condensation in the separator 9.
• the gas 11 is heated and the hydrogen-depleted liquid 13 is sent to the depletion column 25.
• This may include a methane wash section, as for Figure 2, or not as needed.
• methane wash section 25A is present and thus the gas 27 drawn off in the exhaustion column is taken at an intermediate level as in FIG. 2.
• the heat exchanger 23 is simplified and allows a heat exchange between two single fluids, the gas to be cooled 27 and the liquid to be heated 51.
• the gas 27 is taken at the top of the column 25.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Separation By Low-Temperature Treatments (AREA)

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• 2019
  • 2019-03-20 US US16/982,846 patent/US20210055047A1/en not_active Abandoned
  • 2019-03-20 WO PCT/FR2019/050624 patent/WO2019180374A1/fr unknown
  • 2019-03-20 KR KR1020207028610A patent/KR20200135805A/ko active Search and Examination
  • 2019-03-20 SG SG11202008918SA patent/SG11202008918SA/en unknown
  • 2019-03-20 EP EP19716467.6A patent/EP3769022A1/fr active Pending
  • 2019-03-20 CN CN201980020597.7A patent/CN111886465B/zh active Active

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