CN111989528A - 用于从产氮低温空气分离单元增强回收氩和氧的系统和方法 - Google Patents

用于从产氮低温空气分离单元增强回收氩和氧的系统和方法 Download PDF

Info

Publication number
CN111989528A
CN111989528A CN201980026675.4A CN201980026675A CN111989528A CN 111989528 A CN111989528 A CN 111989528A CN 201980026675 A CN201980026675 A CN 201980026675A CN 111989528 A CN111989528 A CN 111989528A
Authority
CN
China
Prior art keywords
stream
argon
oxygen
column
air
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.)
Granted
Application number
CN201980026675.4A
Other languages
English (en)
Other versions
CN111989528B (zh
Inventor
J·R·汉德利
N·M·普罗塞
B·R·克罗默
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Praxair Technology Inc
Original Assignee
Praxair Technology Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Praxair Technology Inc filed Critical Praxair Technology Inc
Publication of CN111989528A publication Critical patent/CN111989528A/zh
Application granted granted Critical
Publication of CN111989528B publication Critical patent/CN111989528B/zh
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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
    • F25J3/04709—Producing crude argon in a crude argon column as an auxiliary column system in at least a dual pressure main column system
    • F25J3/04715—The auxiliary column system simultaneously produces 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
    • F25J3/04006—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
    • F25J3/04006—Providing pressurised feed air or process streams within or from the air fractionation unit
    • F25J3/04012—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of warm gaseous streams; details of intake or interstage cooling
    • F25J3/04024—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of warm gaseous streams; details of intake or interstage cooling of purified feed air, so-called boosted air
    • 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
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04163—Hot end purification of the feed air
    • F25J3/04169—Hot end purification of the feed air by adsorption of the impurities
    • 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
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04163—Hot end purification of the feed air
    • F25J3/04169—Hot end purification of the feed air by adsorption of the impurities
    • F25J3/04181—Regenerating the adsorbents
    • 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
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04187—Cooling of the purified feed air by recuperative heat-exchange; Heat-exchange with product streams
    • 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
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04187—Cooling of the purified feed air by recuperative heat-exchange; Heat-exchange with product streams
    • F25J3/04193—Division of the main heat exchange line in consecutive sections having different functions
    • 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
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04187—Cooling of the purified feed air by recuperative heat-exchange; Heat-exchange with product streams
    • F25J3/04193—Division of the main heat exchange line in consecutive sections having different functions
    • F25J3/04206—Division of the main heat exchange line in consecutive sections having different functions including a so-called "auxiliary vaporiser" for vaporising and producing a gaseous product
    • F25J3/04212—Division of the main heat exchange line in consecutive sections having different functions including a so-called "auxiliary vaporiser" for vaporising and producing a gaseous product and simultaneously condensing vapor from a column serving as reflux within the or another 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
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04187—Cooling of the purified feed air by recuperative heat-exchange; Heat-exchange with product streams
    • F25J3/0423—Subcooling of liquid process streams
    • 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
    • F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
    • F25J3/04254—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using the cold stored in external cryogenic fluids
    • F25J3/0426—The cryogenic component does not participate in the fractionation
    • 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
    • F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
    • F25J3/04284—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams
    • F25J3/0429—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams of feed air, e.g. used as waste or product air or expanded into an auxiliary column
    • F25J3/04303—Lachmann expansion, i.e. expanded into oxygen producing or low 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
    • F25J3/04406—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
    • 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
    • F25J3/04642—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
    • 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
    • F25J3/04684—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 and a bottom re-boiler
    • 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
    • F25J3/04721—Producing pure argon, e.g. recovered from a crude argon column
    • F25J3/04727—Producing pure argon, e.g. recovered from a crude argon column using an auxiliary pure argon column for nitrogen rejection
    • 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
    • F25J3/04769—Operation, control and regulation of the process; Instrumentation within the process
    • F25J3/04793—Rectification, e.g. columns; Reboiler-condenser
    • F25J3/048—Argon recovery
    • 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
    • F25J3/04769—Operation, control and regulation of the process; Instrumentation within the process
    • F25J3/04854—Safety aspects of operation
    • F25J3/0486—Safety aspects of operation of vaporisers for oxygen enriched liquids, e.g. purging of liquids
    • 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
    • F25J2200/08—Processes or apparatus using separation by rectification in a triple pressure main column system
    • 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
    • F25J2200/20—Processes or apparatus using separation by rectification in an elevated pressure multiple column system wherein the lowest pressure column is at a pressure well above the minimum pressure needed to overcome pressure drop to reject the products to atmosphere
    • 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
    • F25J2200/90—Details relating to column internals, e.g. structured packing, gas or liquid distribution
    • F25J2200/94—Details relating to the withdrawal point
    • 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
    • F25J2205/60—Processes or apparatus using other separation and/or other processing means using adsorption on solid adsorbents, e.g. by temperature-swing adsorption [TSA] at the hot or cold end
    • 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
    • F25J2210/00—Processes characterised by the type or other details of the feed stream
    • F25J2210/06—Splitting of the feed stream, e.g. for treating or cooling in different ways
    • 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
    • F25J2210/00—Processes characterised by the type or other details of the feed stream
    • F25J2210/40—Air or oxygen enriched air, i.e. generally less than 30mol% of O2
    • 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
    • F25J2210/00—Processes characterised by the type or other details of the feed stream
    • F25J2210/42—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
    • F25J2215/00—Processes characterised by the type or other details of the product stream
    • F25J2215/40—Air or oxygen enriched air, i.e. generally less than 30mol% of O2
    • 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
    • F25J2215/00—Processes characterised by the type or other details of the product stream
    • F25J2215/42—Nitrogen or special cases, e.g. multiple or low purity N2
    • 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
    • F25J2230/00—Processes or apparatus involving steps for increasing the pressure of gaseous process streams
    • F25J2230/42—Processes or apparatus involving steps for increasing the pressure of gaseous process streams the fluid being 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
    • F25J2230/00—Processes or apparatus involving steps for increasing the pressure of gaseous process streams
    • F25J2230/52—Processes or apparatus involving steps for increasing the pressure of gaseous process streams the fluid being oxygen enriched compared to air, e.g. "crude 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
    • F25J2235/00—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams
    • F25J2235/50—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams the fluid being 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
    • F25J2240/00—Processes or apparatus involving steps for expanding of process streams
    • F25J2240/40—Expansion without extracting work, i.e. isenthalpic throttling, e.g. JT valve, regulating valve or venturi, or isentropic nozzle, e.g. Laval
    • 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
    • F25J2245/00—Processes or apparatus involving steps for recycling of process streams
    • F25J2245/50—Processes or apparatus involving steps for recycling of process streams the recycled stream being oxygen

Abstract

本发明公开了一种中压空气分离单元和空气分离循环，该中压空气分离单元和空气分离循环提供最多至约96％的氩回收率、98％或更大的总氮回收率以及有限的气态氧生产。所述空气分离被配置为从低压塔产生第一高纯度富氧流和第二较低纯度富氧流，其中的一者用作制冷剂以冷凝氩冷凝器中的氩，其中所得的气化氧流用于使变温吸附预纯化器单元再生。所述第一高纯度富氧流的全部或一部分在主换热器中气化以产生所述气态氧产物。

Description

用于从产氮低温空气分离单元增强回收氩和氧的系统和方法
技术领域
本发明涉及氩和氧从产氮低温空气分离单元的增强回收，并且更具体地讲，涉及用于氩的增强回收并且提供中压氧的受限生产的中压空气分离单元和工艺。
背景技术
以生产氮为目标并在中压(即，高于常规空气分离单元压力的压力)下操作的空气分离设备已存在一段时间。在常规空气分离单元中，如果中压下的氮是期望的，则可在高于常规空气分离单元的压力下操作低压塔。然而，这种操作通常会导致氩回收率的显著降低，因为很多氩会在富氧流或富氮流中损失而不是传递至氩塔。
为了在此类中压制氮空气分离单元中增加氩回收率，在20世纪80年代晚期和20世纪90年代早期开发了改进的空气分离循环。参见例如技术出版物Cheung，中压低温空气分 离过程、气体分离和纯化(Moderate Pressure Cryogenic Air Separation Process,GasSeparation&Purification)，第5卷，1991年3月和美国专利号4,822,395(Cheung)。在这些现有技术文献中，公开了氩回收率略高的制氮和氩的空气分离设备。改进的空气分离循环涉及在优选地介于约80至150psia之间的标称压力下操作高压塔，而低压塔优选地在约20至45psia的标称压力下操作，并且氩塔也将优选地在约20至45psia的标称压力下操作。约20至45psia的中压下的高纯度氮(即，>99.98％纯度)的回收率大约为94％。97.3％纯度和约20至45psia之间的压力下的高氩回收率一般高于90％但上限为约93％。
在上述现有技术中压空气分离循环中，来自低压塔的贮槽的高纯度液氧用作氩冷凝器中的制冷剂而不是釜液体。然而，当使用来自低压塔的贮槽的高纯度液氧时，氩塔需要在比常规氩塔更高的压力下操作以便实现氩冷凝器中的所需温度差。氩塔的压力增加需要低压塔和高压塔也在高于常规空气分离单元的压力下操作。
氩冷凝器中使用高纯度液氧也意味着避免了通常进给低压塔的较大釜蒸气流，这使得回收率显著提高。因此，通过该中压空气分离循环可实现对氮、氩和氧的高回收率，尽管与常规空气分离循环相比，高压另外会对回收造成罚分。空气分离单元的中压操作一般有利于氮生产，因为这意味着氮压缩不太耗能并且氮压缩机往往比常规系统的氮压缩机更便宜。
尽管Cheung公布和美国专利号4,822,395中的空气分离单元提供了离开氩冷凝器的高纯度氧蒸气，但该氧流不用作氧产物，因为该流在过低的压力(例如，18psia)下离开该工艺并且将通常要求氧压缩机以足够的压力将氧产物递送给顾客。在一些地区中，由于安全和成本考虑，氧压缩机的使用通常是不可接受的。当使用氧压缩机时，氧压缩机非常昂贵并且通常需要更复杂的工程安全系统，这两者都不利地影响了空气分离单元的资本成本和操作成本。
需要改善的中压空气分离单元和中压空气分离循环，其进一步改善氩回收并且提供有限的氧回收而不需要氧压缩机。
发明内容
本发明可被表征为空气分离单元，该空气分离单元被配置为产生一种或多种高纯度氮产物并且具有98％或更大的氮回收率。本发明空气分离单元包括(i)主空气压缩系统，该主空气压缩系统被配置用于接收进入的进料空气流并且产生经压缩的空气流；(ii)基于吸附的预纯化器单元，该基于吸附的预纯化器单元被配置用于从经压缩的空气流去除水蒸气、二氧化碳、一氧化二氮和烃类并且产生经压缩并且纯化的空气流，其中经压缩并且纯化的空气流被分成至少经压缩并且纯化的空气流的第一部分和经压缩并且纯化的空气流的第二部分；(iii)主换热系统，该主换热系统被配置为冷却经压缩并且纯化的空气流的第一部分以产生蒸气空气流并且部分地冷却经压缩并且纯化的空气流的第二部分；(iv)涡轮膨胀机布置，该涡轮膨胀机布置被配置为使经压缩并且纯化的空气流的经部分冷却的第二部分膨胀以形成排气流，从而向空气分离单元赋予制冷；(V)蒸馏塔系统，所述蒸馏塔系统包括具有介于6.0巴(a)和10.0巴(a)之间的操作压力的高压塔和具有介于1.5巴(a)和2.8巴(a)之间的操作压力的低压塔，所述高压塔和所述低压塔经由冷凝器-再沸器以热传递关系相连，其中所述蒸馏塔系统还包括与所述低压塔操作性地联接的氩塔布置，所述氩塔布置具有至少一个氩塔和氩冷凝器。所述蒸馏塔系统被配置为在所述高压塔中接收所述蒸气空气流的全部或一部分并在所述低压塔中接收所述排气流，并且产生来自所述低压塔的具有大于或等于99.5％氧的第一氧浓度的第一富氧流。
所述氩塔被配置为从所述低压塔接收富氩-氧流，并且产生返回或释放到所述低压塔中的第三富氧塔底馏出物流以及被引导至所述氩冷凝器的富氩塔顶馏出物，所述氩冷凝器被配置为依靠来自所述低压塔的所述第二富氧流来冷凝所述富氩塔顶馏出物以产生粗制氩流或产物氩流、氩回流流和富氧废物流以及液体富氧流。空气分离单元还包括过冷器布置，该过冷器布置与蒸馏塔系统操作性地联接并且被配置为经由与来自低压塔的氮塔顶馏出物流的间接换热来使来自高压塔的釜氧流和来自冷凝器-再沸器的氮流过冷。所述过冷器布置被进一步配置为任选地经由与所述富氧废物流的间接换热来使来自所述低压塔的所述富氧流中的至少一者过冷。
所述空气分离单元被配置为回收大于75％的氩，同时以大于约98％的总氮回收率产生一种或多种高纯度氮产物，并且以大于或等于约3.4巴(a)的压力从所述低压塔产生高纯度泵送氧流。
另选地，本发明可被表征为在低温空气分离单元中分离空气以便以98％或更大的氮回收率产生一种或多种高纯度氮产物的方法。本发明方法包括以下步骤：(a)压缩进入的进料空气流以产生经压缩的空气流；(b)在基于吸附的预纯化单元中纯化经压缩的空气流，该基于吸附的预纯化单元被配置为从经压缩的空气流去除水蒸气、二氧化碳、一氧化二氮和烃类以产生经压缩并且纯化的空气流；(c)将经压缩并且纯化的空气流分成至少经压缩并且纯化的空气流的第一部分和经压缩并且纯化的空气流的第二部分；(d)在适用于在低温蒸馏系统中精馏的温度下将经压缩并且纯化的空气流的第一部分冷却为蒸气空气流，并且部分地冷却经压缩并且纯化的空气流的第二部分；(e)在涡轮中使经压缩并且纯化的空气流的经部分冷却的第二部分膨胀以形成排气流；(f)在低温蒸馏塔系统中精馏液体空气流和排气流，该低温蒸馏塔系统包括具有介于6.0巴和10.0巴之间的操作压力的高压塔和具有介于1.5巴和2.8巴之间的操作压力的低压塔，该高压塔和该低压塔经由冷凝器再沸器以热传递关系相连，其中精馏步骤产生来自低压塔的具有大于或等于99.5％氧的第一氧浓度的第一富氧流、来自低压塔的氮塔顶馏出物流；以及来自冷凝器-再沸器的冷凝氮流；(g)在氩塔布置中对从所述低压塔提取的氧-氩流进行精馏，所述氩塔布置被配置为产生作为塔底馏出物流的第三富氧流和富氩塔顶馏出物；(h)经由与来自所述低压塔的所述氮塔顶馏出物流的间接换热来使来自所述高压塔的第四富氧流(即，釜流)和来自所述冷凝器-再沸器的所述冷凝氮流过冷，以及在过冷器单元中任选地经由与富氧废物流的间接换热来使来自所述低压塔的一种或多种富氧流过冷；(i)使来自所述氩塔的所述第三富氧流返回至所述低压塔；(j)将所述富氩塔顶馏出物从所述氩塔引导至氩冷凝器；以及(k)在所述氩冷凝器中因来自所述低压塔的所述第二富氧流而冷凝所述富氩塔顶馏出物以产生粗制氩流或产物氩流、氩回流流和富氧废物流。
与所述空气分离系统一样，本发明的空气分离方法提供大于75％的氩回收率，同时以大于约98％的回收率产生一种或多种高纯度氮产物，并且以大于或等于约3.4巴(a)的压力从所述低压塔产生高纯度泵送氧流。
在本发明系统和方法中，基于吸附的预纯化器单元优选地是被配置为纯化经压缩的空气流的多床变温吸附单元，该多床变温吸附单元被配置为使得每个床在在线操作阶段与离线操作阶段之间交替，该在线操作阶段从经压缩的空气流吸附水蒸气、二氧化碳和烃类，并且在该离线操作阶段中，使用优选地具有大于90％氧含量且最多至约99.5％氧的富氧废物流来再生或吹扫该床。基于吸附的预纯化器单元优选地还包括蒸汽加热器、电加热器或其他非燃烧式加热器，其被配置为将富氧废物流加热至小于或等于约450℉、优选地小于约400℉的温度以用于再生变温吸附单元中的吸附床。
所述优选氩塔布置被配置为在介于约1.3巴(a)和2.8巴(a)之间的压力下操作，并且可被配置为具有介于180和260个之间的分离级的超级塔和高比率塔。另选地，氩塔布置可被配置为具有介于185和270个之间的分离级的极超级塔(ultra-superstaged column)。任选地，被配置为精制粗制氩流以产生高纯度氩产物流的氩精制系统可设置在氩冷凝器的下游，氩精制系统。在此类实施方案中，氩精制系统可为基于氩液体吸附的系统、基于氩气相吸附的系统或基于催化脱氧的系统。
附图说明
虽然本发明的结论是申请人视为他们的发明内容且清楚地指出发明主题的权利要求，但相信本发明在结合附图考虑时将得到更好的理解，其中：
图1是根据本发明的一个实施方案的空气分离单元的示意性工艺流程图；
图2是根据本发明的另一个实施方案的空气分离单元的示意性工艺流程图；
图3是根据本发明的又一个实施方案的空气分离单元的示意性工艺流程图；
图4是根据本发明的再一个实施方案的空气分离单元的示意性工艺流程图；
图5是蒸馏塔系统内的具有增加的压力的根据又一个实施方案的空气分离单元的示意性工艺流程图；并且
图6是蒸馏塔系统内的具有增加的压力的根据再一个实施方案的空气分离单元的示意性工艺流程图。
具体实施方式
本发明所公开的系统和方法提供了在中压空气分离单元中的低温空气分离，其特征在于非常高的氮回收、高氩回收以及有限的高纯度氧生产。如下文更详细地讨论，取自低压塔的高纯度富氧流的一部分或取自低压塔的低纯度富氧流用作氩冷凝器中的冷凝介质以使富氩流冷凝，并且来自氩冷凝器的富氧沸腾溢出然后用作吹扫气体以使基于吸附的预纯化器单元中的吸附剂床再生。在随后的段落中提供本发明系统和方法的细节。
中压空气分离单元中的氮、氩和氧的回收
转到附图，并且具体地讲图1，示出了空气分离单元10的简化示意图。从广义上讲，所描绘的空气分离单元包括主进料空气压缩机组或系统20、涡轮空气回路30、任选的增压器空气回路40、初级换热器系统50以及蒸馏塔系统70。如本文所用，主进料空气压缩机组、涡轮空气回路和增压器空气回路共同构成“热端”空气压缩回路。类似地，主换热器、基于涡轮的制冷回路的部分和蒸馏塔系统的部分被称为通常容纳绝缘冷箱中的“冷端”设备。
在图中所示的主进料压缩机组中，进入的进料空气22通常被抽吸穿过空气吸滤器外壳(ASFH)并且在多级中间冷却的主空气压缩机布置24中被压缩至可介于约6.5巴(a)至约11巴(a)之间的压力。该主空气压缩机布置24可包括串联或并联布置的整体齿轮式压缩机级或直接驱动压缩机级。离开主空气压缩机布置24的经压缩的空气流26被进料至具有一体式除雾器的后冷却器(未示出)，以去除进入的进料空气流中的游离水分。通过用冷却塔水冷却经压缩进料空气，在后冷却器中将来自主空气压缩机布置24的最后压缩级的压缩的压缩热去除。来自该后冷却器以及主空气压缩布置24中的一些中间冷却器的冷凝物优选地输送到冷凝物罐，并且用于向空气分离设备的其他部分供应水。
然后将冷却且干燥的经压缩空气流26在预纯化单元28中纯化以从该冷却且干燥的经压缩空气进料中去除高沸点污染物。如本领域所熟知，预纯化单元28通常包含根据变温吸附循环操作的氧化铝和/或分子筛的两个床，在该变温吸附循环中水分及其他杂质(诸如二氧化碳、水蒸气和烃类)被吸附。这些床中的一个床用于预纯化该冷却且干燥的经压缩空气进料，而另一个床是优选地利用来自空气分离单元的废氮的一部分再生的。这两个床定期交换功用。在设置在预纯化单元28下游的粉尘过滤器中，从经压缩、预纯化的进料空气中去除颗粒以产生经压缩、纯化的空气流29。
经压缩并且纯化的空气流29在包括高压塔72、低压塔74和氩塔129的多个蒸馏塔中被分离为富氧馏分、富氮馏分和富氩馏分。然而，在这种蒸馏之前，通常将经压缩且预纯化的空气流29分成多个进料空气流，所述多个进料空气流可包括锅炉空气流(参见图3和图4的320)和涡轮空气流32。可将锅炉空气流在增压压缩机布置(参见图3和图4中的340)中进一步压缩，并且随后在后冷却器(参见图3和图4中的340)中冷却以形成增压空气流360，然后将该增压空气流进一步冷却至主换热器52中的精馏所需的温度。优选地通过与包括氧流197、386的加热流以及来自蒸馏塔系统70的氮流195的间接换热来在主换热器52中完成对空气流的冷却或部分冷却，以产生经冷却的进料空气流。
使经部分冷却的进料空气流38在涡轮35中膨胀，以产生被引导至低压塔74的排气流64。空气分离单元10的制冷也通常由涡轮35和其他相关的冷的和/或热的涡轮布置生成，该涡轮布置诸如为如本领域中所公知的闭环加热制冷回路。完全冷却的空气流47以及高压空气流(参见图3和图4中的流364)被引入高压塔72中。任选地，不在涡轮进料流38中抽出涡轮空气回路30中流动的小部分空气。在换热器52的冷端处抽出任选的增压流48，使该增压流完全或部分冷凝，在阀49中降低压力，并且在离塔底若干级处进料至高压塔72。仅在所泵送的氧流386的大小足够高时利用流48。
主换热器52优选地为钎焊铝制板翅式换热器。此类换热器是有利的，因为它们具有紧凑设计、高传热速率，而且它们能够处理多个流。它们被制造为完全钎焊和焊接的压力容器。对于小型空气分离单元而言，具有单个芯的换热器可能已足够。对于处理较高流量的较大空气分离单元而言，换热器可由必须并联或串联连接的若干芯构造而成。
基于涡轮的制冷回路通常被称为下塔涡轮(LCT)布置或上塔涡轮(UCT)布置，其用于向双塔或三塔低温空气蒸馏塔系统提供制冷。在图中所示的UCT布置中，经压缩、冷却的涡轮空气流32优选地在约6巴(a)至约10.7巴(a)之间的范围内的压力下。将经压缩、冷却的涡轮空气流32引导至或引入主换热器或初级换热器52中，在其中将该经压缩、冷却的涡轮空气流部分冷却至约140开尔文至约220开尔文之间的范围内的温度以形成经部分冷却、压缩的涡轮空气流38，该经部分冷却、压缩的涡轮空气流被引入涡轮35中以产生冷排气流64，该冷排气流随后被引入蒸馏塔系统70的低压塔74中。由该流38的膨胀而产生的补充制冷由此被直接施加到低压塔72，从而减轻了主换热器52的一些冷却负荷。在一些实施方案中，涡轮35可与用于直接或通过适当的齿轮装置进一步压缩涡轮空气流32的增压压缩机34联接。
虽然图中所示的基于涡轮的制冷回路被示出为上塔涡轮(UCT)回路(其中涡轮排气流被引导至低压塔)，但可设想到基于涡轮的制冷回路另选地可为下塔涡轮(LCT)回路或部分下塔涡轮(PLCT)(其中膨胀的排气流被进料至蒸馏塔系统70的高压塔72)。更进一步地，基于涡轮的制冷回路可为本领域技术人员众所周知的LCT布置、UCT布置和/或热再循环涡轮(WRT)布置的某种变型或组合。
在包括高压塔72、低压塔74、超级氩塔129、冷凝器-再沸器75和氩冷凝器78的蒸馏塔系统70内分离进入的进料空气流的上述组分(即，氧、氮和氩)。高压塔72通常在约6巴(a)至约10巴(a)之间的范围内操作，而低压塔74在约1.5巴(a)至约2.8巴(a)之间的压力下操作。高压塔72和低压塔74优选地以热传递关系相连，使得从接近高压塔72的顶部提取为流73的富氮蒸气塔顶馏出物的全部或一部分在位于低压塔74的基部的冷凝器-再沸器75内因驻留在低压塔74的底部中的富氧液体塔底馏出物77而冷凝。富氧液体塔底馏出物77的沸腾引发在低压塔74内形成上升气相。该冷凝产生液体含氮流81，该液体含氮流被分成干净搁板回流流83和富氮流85，该干净搁板回流流可用于回流低压塔74以引发这种低压塔74中下降液相的形成，并且该富氮流回流高压塔72。
经冷却的进料空气流47优选地是略高于其露点的蒸气空气流，但其可处于或略低于其露点，该经冷却的进料空气流被进料至高压塔中，从而因多个传质接触元件(被示出为塔盘71)内发生上升气相与回流流85所引发的下降液相之间的传质而实现精馏。这产生了粗液氧塔底馏出物86(也称为釜液体，其作为流88取出)和富氮塔顶馏出物89(作为干净搁板液体流83取出)。
在低压塔中，上升气相包括来自冷凝器-再沸器的汽化气体以及来自涡轮35的排气流64，该排气流在过冷单元99B中过冷并且作为蒸气流引入在低压塔72的中间位置处。下降液体由氮回流流83引发，该氮回流流被送至过冷单元99A，其在此处过冷并且随后先在阀96中膨胀，再在接近低压塔的顶部的位置处引入至低压塔74。如果需要，可经由阀101取出过冷氮回流流83的小部分作为液体氮产物98。
低压塔74还设置有多个传质接触元件，这些接触元件可以是塔盘或规整填料或散堆填料或低温空气分离领域中的其他已知元件。低压塔74中的这些接触元件被示出为规整填料79。在低压塔74内发生的分离产生了富氧液体塔底馏出物77，该富氧液体塔底馏出物被提取为具有大于99.5％的氧浓度的富氧液体流377。低压塔还产生作为气态氮产物流95提取的富氮蒸气塔顶馏出物。
富氧液体流377可被分离成在泵385中泵送的第一富氧液体流380，并且所得的泵送氧流386被引导至主换热器52，其中它被加热以产生高纯度气态氧产物流390。富氧液体流377的第二部分被转移为第二富氧液体流90。将第二富氧液体流90优选地经由泵180来泵送，然后经由与富氧废物流196的间接换热来在过冷单元99B中过冷，之后传递至氩冷凝器78，其在此用于冷凝从氩塔129的塔顶馏出物123取出的富氩流126。作为另外一种选择，可在泵385之后转移第二富氧液体流90。这将避免对泵180的需要。如图1所示，过冷第二富氧液体流90的一部分可作为液氧产物185。作为另外一种选择，第一液氧流的一部分可作为液氧产物。
从氩冷凝器78汽化的蒸发的氧流是在过冷器99B内加热的富氧废物流196。将经加热的富氧废物流197引导至主换热器或初级换热器，然后用作吹扫气体以再生基于吸附的预纯化器单元28。另外，可从低压塔提取废物氮流93以控制气态氮产物流95的纯度。优选地将废物氮流93与过冷器99B上游的富氧废物流196合并。另外，在一些情况下，当可获得比操作氩冷凝器78所需更多的氧时，可能需要蒸气废氧流97。这在氩产量减少时是最可能的。
从氩冷凝器容器120抽出液体流130，使该液体流穿过凝胶捕集器370并且返回至低压塔74的基部或基部附近。凝胶捕集器370用于去除原本可能积聚在系统中的二氧化碳、一氧化二氮和某些重质烃。另选地，可经由流130来抽出小流量作为来自系统的排放流，使得凝胶捕集器140被消除(未示出)。
优选地，图中所示的氩冷凝器是降流氩冷凝器。降流构型使得冷凝流与沸腾流之间的有效温差(AT)更小。如上所指示，更小的AT可引起氩塔、低压塔和高压塔内降低的操作压力，这转换成产生各种产物流所需的功率减少以及氩回收率提高。降流氩冷凝器的使用还实现了塔级数量的潜在减少，特别是对于氩塔而言。从资本的角度来看，氩降流冷凝器的使用也是有利的，部分原因是本发明公开的空气分离循环中已经要求泵180。另外，由于液体流130已经提供离开氩冷凝器壳体的连续液体流，该液体流还提供再沸表面的必要润湿以防止氩冷凝器“蒸干”。
使氮产物流95穿过过冷单元99A以经由间接换热来使氮回流流83和釜液体流88过冷。如上所述，过冷氮回流流83在阀96中膨胀并被引入低压塔74的最高位置，而过冷釜液体流88在阀107中膨胀并被引入低压塔74的中间位置。在穿过过冷单元99A之后，经加热的氮流195在主换热器或初级换热器52内进一步加热以产生经加热的气态氮产物流295。
第一富氧液体流380的流量可为离开系统的总富氧流的多达约20％。该布置的氩回收率介于约75％和96％之间，这大于现有技术的中压空气分离系统。虽然未示出，但取自外部源(未示出)的液氮流可与第二富氧液体流90和用于在氩冷凝器78中冷凝富氩流126的组合流组合，以增强氩回收。
在图2中示出了本发明的空气分离单元和相关联的空气分离循环的另选实施方案。图2所示的空气分离设备中的许多部件类似于上文参考图1所述的那些部件，并且为了简洁起见将不再重复。与图1所示的实施方案相比，图2的实施方案之间的差异在于两个单独富氧液体流取自低压塔。第一富氧液体流380直接取自贮槽，富氧液体塔底馏出物77位于该贮槽中并且具有大于99.5％的氧浓度。第一富氧液体流380在泵385中泵送并被引导至主换热器52，其中它被加热以产生高纯度气态氧产物流390。第一液氧流380的一部分可优选作为液氧产物395。
第二富氧液体流398优选地在比第一富氧液体流380被提取的点高若干级的位置处取自低压塔74，并且将具有约93％和99.7％之间的氧浓度。将第二富氧液体流398经由泵180来泵送，然后经由与富氧废物流196的间接换热来在过冷单元99B中过冷，之后传递至氩冷凝器78，其在此用于冷凝从氩塔129的塔顶馏出物123取出的富氩流126。与图1的实施方案一样，取自外部源(未示出)的液氮流可与第二富氧液体流398组合以试图增强氩回收。组合流用于在氩冷凝器78中冷凝富氩流126。
在图2中，在泵385之后，流392优选地穿过凝胶捕集器370。然后其返回至低压塔74的基部或基部附近。从氩冷凝器容器120抽出液体流130并且使该液体流在流398的抽吸位置正下方返回至低压塔。另选地，可经由流392来抽出小流量作为来自系统的排放流，使得凝胶捕集器140被消除(未示出)。在流392从系统排出的情况下，其可另选地在泵385之前从高纯度富氧液体流380转移。在这种情况下，流395可表示排出流或除排出流之外的液氧产物流。
图2所示的布置提供了与图1的布置方式相比以及与现有技术系统相比的四个潜在优点，特别是对于不需要最大氩回收的情景。使用第二富氧液体流398(即，较低纯度的液氧)代替第一富氧液体流380确实必须对从空气分离设备的氩回收进行罚分，因为氩是第二富氧液体流398中的主要杂质。该配置的主要移出是其使得第一富氧流380能够以较高氧纯度抽出。
图2的布置的附加益处是减小的功率消耗的能力。由于送至氩冷凝器的较低纯度液氧在较低温度下沸腾，因此氩冷凝器中的冷凝氩可处于低压以实现所需的Δ温度(ΔT)。低压氩意味着氩塔、低压塔和高压塔可在低压下操作，但低压塔和氩塔将仍在中压下操作。由于蒸馏塔系统中的低压，可减小主空气压缩机系统的功率消耗。
图2所示的布置的另一个潜在益处是氩塔中所需的分离级数由于其较低的操作压力而减小。图2所示的布置的第四益处是其实现更大的高压或泵送的氧产物抽吸。减小的氩回收转化为减小的氩冷凝器负荷，并且因此氩冷凝器所需的较低纯度的氧液体的流量减少。这继而使得能够进行更大的泵送氧产物抽吸。所泵送的氧产物现在可高达离开系统的总富氧流的50％。在该极端情况下，氩回收率可低至30％。
在图3中示出了又一个另选的实施方案。而且，由于图3所示的空气分离设备中的许多部件类似于上文参考图1和图2所述的那些部件，因此此类通用部件的描述将不再重复。图3所示的实施方案和图1的实施方案之间的差异是增压器空气压缩机(BAC)回路。
图3(和图4)所示的BAC回路用于生成高压空气流364，该高压空气流的压力高于主换热器52中的泵送氧流386的压力。BAC回路优选地采用经压缩并且纯化的进料空气29的转移部分。该转移的BAC流320然后在增压器空气压缩机340中进一步压缩并且然后在后冷却器330中冷却。所得的高压增压空气流360在主换热器52中被进一步冷却至适用于蒸馏塔系统70中的精馏的温度，同时使主换热器52中的相邻泵送氧流386沸腾。如图3所示，离开主换热器52的冷端的液化增压空气流364优选地在阀365中膨胀并且然后供应到高压塔72。当泵送的氧流386具有足够高的流量或压力并且需要BAC回路来产生高压空气流时，图3的实施方案特别有用，该高压空气流的流量和压力足以在主换热器52中气化泵送氧流386。该布置还可用于增强空气分离单元的安全方面，因为与主换热器52中的沸腾氧流相邻的增压空气流360具有更高的压力。图3的排出流130和凝胶捕集器370的配置类似于上文参照图1所述的配置。
在图4中示出了再一个另选的实施方案。而且，由于图4所示的空气分离设备中的许多部件类似于上文参考图3所述的那些部件，因此此类通用部件的描述将不再重复。与图3的实施方案相比，图4所示的实施方案之间的差异是一组流量控制阀378、379，其控制向氩冷凝器78的富氧液体流的流量。
图4的实施方案尤其可用于需要处于高流速和低流速两者的气态氧产物的高压的空气分离单元。在图4所示的实施方案中，示出了两个阀以从供应氩冷凝器78的低压塔74中选择氧源。第一阀378控制直接取自富氧液体塔底馏出物77并且具有大于99.5％的氧浓度的第一富氧液体流380的流量。第二阀379控制具有约93％和99.7％之间的氧浓度的第二富氧液体流390的流量，该第二富氧液体流在比低压塔贮槽或第一富氧液体流380的提取点高若干级的位置处取自低压塔74。阀378、379优选地以开/关模式协同工作，使得当一个阀打开时，另一阀关闭。
如果需要相对低的气态氧流，并且期望较高的氩回收，则阀378打开并且阀379关闭，使得第一富氧液体流380或较高纯度氧流被进料到氩冷凝器78。相反，如果需要较高的气态氧流，或者当不需要高氩回收时期望附加的功率节省，则阀378关闭并且阀379打开，使得第二富氧液体流390或较低纯度氧流被进料到氩冷凝器78的沸腾侧。应当指出，阀378优选地为阻滞和排放布置以防止在泄漏的情况下污染阀378两端的氧。
所得的富氧流398在泵180中泵送，并且然后经由与富氧废物流195的间接换热来在过冷单元99B中过冷，之后传递至氩冷凝器78，其在此用于冷凝从氩塔129的塔顶123取出的富氩流126。如上文参考其他实施方案所讨论，取自外部源(未示出)的液氮流可与富氧液体流398组合以试图增强氩回收。组合流将用于在氩冷凝器78中冷凝富氩流126。图4的排出流130和392以及凝胶捕集器370的配置类似于上文参照图2所述的配置。
还应当指出，为了能够在将较低纯度氧进料到氩冷凝器78的沸腾侧时实现期望的功率减小，空气分离单元10必须被设计成在与该模式相关联的低压下有效地操作。这意味着例如蒸馏塔72、74必须被设计用于较大的直径以便在压力较低时以全容量操作。同样，为了使空气分离单元在将较高纯度氧进料到氩冷凝器78的沸腾侧时有效地操作，空气分离单元10必须被设计成使产物层处于较高塔压。这意味着蒸馏塔72、74必须针对该模式具有足够的分离级，因为组分之间的相对挥发性在高压下更靠近彼此。主空气压缩机24、产物压缩机(未示出)和锅炉空气压缩机340也必须被设计成适应以任一模式的操作。例如，锅炉空气压缩机340可能必须在气态氧产物速率相对低时与某种再循环回路345一起操作，除非其被设计成具有变速驱动或直接驱动马达。
氩回收和精制
在上述实施方案中采用的氩塔布置可优选地被配置为：(i)与第二氩塔诸如高比率氩塔操作性地联接的第一氩塔(例如，氩超级塔或粗制氩塔)；或(ii)与低压塔结构集成并且优选地与下游氩精制系统联接的除氩塔或粗制氩塔。
使用优选具有高比率氩塔160的氩超级塔129的实施方案在附图中示出。超级氩塔129从低压塔74接收包含氩和氧的蒸气进料121，并且从位于超级氩塔129上方的氩冷凝器78接收向下流动的富氩回流122。超级氩塔129具有约180与260之间的分离级，并且用于通过以下方式精馏含氩和氧的蒸气：将氩与氧分离成富氩塔顶馏出物蒸气126和富氧液体塔底馏出物，该富氧液体塔底馏出物作为流124返回至低压塔。超级氩塔129内的优选传质接触元件125优选地为规整填料。优选地将所得的富氩蒸气塔顶馏出物126的全部或一部分引导到氩冷凝器78，在该氩冷凝器中其因来自低压塔74的过冷富氧流而冷凝。所得冷凝物是从氩冷凝器78取出的粗液体氩流，该粗液体氩流大部分作为氩回流流127返回至超级氩塔129。
高比率氩塔160还接收作为流162离开氩冷凝器78的粗液体氩流的一部分，流162在阀164中进行压力调节并且引入在高比率氩塔160的中间位置处。在高比率塔160内精馏粗氩以形成液体氩塔底馏出物166和含氮高比率塔顶馏出物168。从高比率氩塔160的液体氩塔底馏出物166取出高纯度液体氩产物流165。
还将从接近高压塔72的顶部提取的富氮塔顶馏出物的一部分作为流163转移到设置在高比率氩塔160的底部处的高比率塔再沸器170，在此冷凝该流以形成液体氮流172。然后将液体氮流172引导或转移到高比率塔冷凝器175，其在此提供制冷负荷以冷凝或部分冷凝富氮高比率塔顶馏出物168。离开高比率塔再沸器175的气化氮流174被引导至过冷单元99A上游的氮产物流95并与其混合。
从高比率塔160的顶部附近的位置取出富氮高比率塔顶馏出物168，随后在高比率塔冷凝器175中冷凝或部分冷凝该富氮高比率塔顶馏出物。将所得流176送至分相器177，该分相器被配置为排放蒸发的部分178，同时使液体部分179作为回流返回至高比率氩塔160。使用该布置，可从空气分离设备获得高达96％的氩回收率。
设想了使用另选的氩生产和精制选项的其他实施方案以用于与本发明的系统和方法一起使用。可在氩精制系统中回收或纯化从氩塔布置中抽出的粗制富氩流，诸如基于液体吸附的氩纯化/精制系统、基于气相吸附的氩纯化/精制系统、或基于催化脱氧的氩纯化/精制系统。在另一个替代方案中，消除了高比率氩塔，并且从超级塔129(未示出)直接产生产物纯度氩。在这种情况下，在超级塔的顶部处包括另一个蒸馏区段。在称为巴氏灭菌区的该区段中，可去除少量氮以确保可靠的产物氩纯度。从塔129的顶部排放更富氮的小流，并且在巴氏灭菌区下方抽出产物氩。需要低压塔中的蒸气抽吸流121正上方的更高蒸馏区段以使得更少氮进入超级塔129。美国专利号5,133,790中描述了该另选形式。
在蒸馏塔系统中的通过增加的压力的氮和氩的回收
在图5和图6中示出了本发明的空气分离系统和方法的附加实施方案。这些实施方案允许蒸馏塔系统的高压塔和低压塔在与上文参考图1至图4所述的实施方案相比略微增加并且通常比由氩塔冷凝器自然设定的压力更高的压力下操作。然而，保持氩塔在最小压力下的操作以避免大氩回收损失。氩塔最小压力通常通过氩冷凝器中的因低压氧沸腾流而引起的冷凝来设定。蒸馏塔系统的高压塔和低压塔中的增加的压力将产生高压气体氮产物，尽管具有对应的氮回收减少和功率消耗增加。与高压塔和低压塔的增加的压力相关联的一些优点可在降低成本或可能消除产物氮压缩机以及可能减小低压塔和高压塔的塔直径和相关联的资本成本方面实现。
图5的实施方案和图1至图4所示的那些实施方案之间的关键差别包括阀140和泵142。通过使进料至氩塔的包含氩和氧的蒸气流121的压力下降(通过阀140)，氩塔可在其最小压力下或接近其最小压力操作。由于氩塔129相对于低压塔74的较低操作压力，因此要求泵142使塔底馏出物液体124从氩塔返回到低压塔74。在图5的实施方案中，低压塔的压力范围优选地介于约1.7巴(a)至3.5巴(a)之间，而高压塔的压力范围优选地介于约7巴(a)至12.5巴(a)之间，并且氩塔的压力保持介于约1.5巴(a)至约2.8巴(a)之间。
在图6的实施方案中，进料至氩塔的包含氩和氧的蒸气流121首先传递到设置在氩塔129的基部内的再沸器143中。完全冷凝或部分冷凝的流144通过阀141减压，并且然后对氩塔底部上方的若干分离级(优选地在氩塔底部上方的介于约3个级至10个级)进料。由于使用再沸器143，低压塔74的压力必须相对于氩塔129的压力升高。具体地，在所示的实施方案中，低压塔的压力优选地比氩塔中的压力高至少0.35巴(a)。虽然图6的实施方案包括与再沸器143和泵142相关联的附加资本成本，但益处是与图5所示的实施方案相比，该实施方案应当提供附加的1％至5％的氩回收率并且还应当允许氩塔内的分离级数的减小。
使用富氧废物流作为基于吸附的预纯化器的再生气体
当使用基于吸附的预纯化单元时，期望让经压缩、干燥、预纯化且冷却的空气流的连续流进入空气分离单元的蒸馏塔系统。预纯化过程优选地通过使用多个吸附剂床来完成，优选地布置为双床变温吸附单元。在优选的双床变温吸附预纯化器中，一个床处于吸附进入的进料空气中的杂质的在线操作阶段，而另一个床处于离线操作阶段，在该阶段中使用高纯度废物氧流的全部或一部分来再生该床。在许多双床吸附循环中，当一个床从在线操作阶段切换到离线操作阶段并且另一个床从离线操作阶段切换到在线操作阶段时，可存在两个床均处于在线操作阶段的短重叠时间段。
如本领域所熟知，在在线阶段中操作的吸附床可仅保持在线，直到其达到其吸附杂质的容量并且将可能发生杂质穿透。杂质穿透点一般由污染物(例如，水蒸气和二氧化碳)在出口处达到不可接受的水平(表明吸附床被污染物饱和)所需的时间定义。一旦接近穿透点，就使在线吸附床变为离线并且使先前再生的床恢复在线以吸附进料空气中的杂质。
优选的变温吸附单元是复合吸附布置，该复合吸附布置包括下方的至少一层氧化铝284和至少一层分子筛286。氧化铝用于去除大部分水蒸气，而分子筛用于从进入的进料空气去除水蒸气、二氧化碳、一氧化二氮和烃污染物。复合床通常被设计为在床的底部具有足够的氧化铝以从经压缩的空气进料流去除大部分水，并且由其上方的筛层去除剩余的水。复合床通常具有更低的吹扫或再生气体流需求并且需要比全筛床少大约30％的再生能量，因为它们可在更低温度下再生。
变温吸附预纯化器优选地以在约6与12小时之间范围内的“在线”吸附的循环时间操作。由于这些长循环时间，与变压吸附单元相比，变温吸附预纯化器可在更长的时间跨度上减压和再加压，从而导致空气分离单元的更稳定的塔操作。更短的循环时间有助于保持初始资本成本较低，因为竖直和水平取向的床中需要更少吸附剂和更矮的吸附剂高度。然而，更长的循环时间会因泄料和再生能量的寄生损失减少而产生减少的操作成本。进入变温吸附预纯化器的经压缩的空气或进料空气温度可在37℉至高达75℉的范围内，并且通常优选地将进入的经压缩的空气流冷却到约40℉至60℉之间。用于冷却经压缩的空气流的两种常见形式的进料空气冷却器包括双级后冷却器和直接接触式后冷却器(未示出)。
变温吸附预纯化器还需要吹扫或再生气体流，该吹扫或再生气体流介于进料空气流或进入的压缩空气流的流量的约5％和30％之间，并且更优选等于进入的压缩空气流的流量的约10％。吹扫或再生气体流与进料空气流逆流地穿过床。吹扫或再生气体流将再生热量承载到床中，在床中它致使污染物从吸附剂解吸，从床去除解吸的污染物，并且在再生循环结束时冷却床。在再生循环开始时，加热吹扫气体以进行热吹扫。稍后在该循环中，不加热吹扫气体，并且这是冷吹扫。
再生加热器的尺寸必须被设定成使得其可将吹扫或再生气体流从其初始温度加热到期望的再生温度。再生加热器的尺寸设定的重要考虑因素是吹扫或再生气体的初始温度、期望的吹扫或再生气体流量、加热器与吸附床之间的热损失以及加热器效率。当再生或吹扫气体是富氧流时，出于安全原因，加热器出口温度应小于约400℉。在选择特殊材料的情况下，加热器出口温度可安全地达到450℉之高。另外，当再生或吹扫气体是富氧流时，仅应使用蒸汽加热器、电加热器或其他非燃烧式加热器。
吹扫/进料(P/F)比率是吹扫或再生气体流与进料空气流的比率。所需的P/F比率取决于若干变量，包括吸附剂类型、再生温度、循环时间和热吹扫比率，但优选地在约0.05与0.40之间的范围内。更高的再生温度会降低所需的P/F比率。更长的循环时间需要略微更低的P/F比率。热吹扫比率是热吹扫时间与总吹扫时间(即，热吹扫时间加冷吹扫时间)的比率。约0.40的热吹扫比率通常用于变温吸附预纯化器，以确保足够的冷吹扫时间可用于有效地冷却吸附床，但一些空气分离单元可能以较高热吹扫比率操作。更小的热吹扫比率产生更高的P/F比率，因为必须在更短的时间量内将相同量的热量携带到吸附床中。
再生鼓风机297优选地用于升高废物流290的压力，使之足以穿过基于吸附的预纯化单元以实现再生目的。离开再生鼓风机297后，废物流290的压力升高以使得其将穿过再生加热器、预纯化器容器及其相关联的吸附床和相关联的阀，进而排放到大气。再生鼓风机297优选地被配置为使离开主换热器的废物流290的压力升高约0.1巴(a)至0.3巴(a)。
虽然再生鼓风机的使用是任选的，但在没有再生鼓风机的情况下操作空气分离单元需要蒸馏塔系统在足够高的压力下运行，使得离开主换热器的废物流可穿过预纯化单元。换言之，再生鼓风机的使用允许氩塔和低压塔的操作压力降低约0.15巴(a)至0.5巴(a)并且高压塔的压力降低约0.35巴(a)至2.0巴(a)。
所公开的空气分离循环中的再生鼓风机的主要有益效果主要与氩生产相关。在没有再生鼓风机的情况下，高氩回收率是可行的，但氩塔中的更高压力仍会使得需要氩塔中的许多分离级和低压塔中的潜在附加级。氩回收的设计和操作灵敏度也较大。在使用再生鼓风机的情况下，蒸馏塔压力的伴随降低往往使氩回收更容易。氩回收率将提高，尤其是在目标氩回收率更低并且还减少氩塔和低压塔的分级需求的场景或实施方案中。
重新参考图1，示出了具有变温吸附预纯化器28的空气分离单元10的示意图。在变温吸附过程中，一般存在每个吸附床进行的多个不同步骤，即：共混、吸附；共混、减压、热吹扫、冷吹扫；和再加压。下表1示出了两个吸附床内的步骤的执行的相关性。
Figure BDA0002730394830000171
表1：双床变温吸附循环和时间的示例
在上述示例中，在“共混”步骤期间，两个吸附床均“在线”并且阀262、264、266和268打开，而阀304、306、314和316关闭。进料空气流在该步骤期间在两个床之间均匀分流且该系统中没有吹扫或再生气体。当“在线”时，吸附床281和282吸附水蒸气和其他污染物，诸如二氧化碳。该共混步骤的目的是稀释在再生期间留在吸附床中的余热量，因此防止受热的流往回进给到容纳蒸馏塔的冷箱。
在“共混”步骤后，一个吸附床281经受再生过程并且变为“离线”，而另一个吸附床282接收完全的进料流并且经历吸附步骤，在该步骤中继续吸附水蒸气、二氧化碳和烃类。此类再生过程通过四个不同步骤完成，这四个不同步骤包括：减压；热吹扫；冷吹扫；和再加压。本领域技术人员应当理解，还可包括其他步骤。在减压步骤期间，吸附床281从进料压力减压到更低压力，通常减压到接近大气压力。这通过关闭阀262和266并且打开阀314来完成。该更低压力是再生压力并且该步骤持续约10分钟，但时间长度可根据设备约束或工艺限制而变化。一旦减压，热吹扫步骤就开始，其中使用加热器299来加热再生富氧废物流290以将富氧废物流的温度增加到高于进料空气的温度并且通常高于300℉且低于380℉的温度，具体取决于工艺和吸附材料约束。可容许高达400℉的操作。在特殊材料选择的情况下，该操作可高达450℉。在该时间期间，阀304打开并且允许富氧废物流穿过吸附床281。在经过一定时间段之后(在该示例中，在170分钟之后)，富氧废物流绕过加热器299或加热器(如果电加热器)被关闭，从而将废物流气体温度降低到接近环境状况，通常但不总是介于约40℉和100℉之间。关闭电加热器或绕过加热器开始冷吹扫步骤，该冷吹扫步骤继续用富氧废物流吹扫吸附剂床，但不存在热量，这降低吸附剂床的温度以及使热量向前推进通过吸附剂床。在该示例中，该冷吹扫步骤持续约250分钟。
通过关闭阀314和304并且打开阀262来引发吸附床281的再加压步骤。这允许经压缩的空气流26的一部分将容器从接近环境压力加压到升高的进料压力。一旦加压到进料压力，吸附床281和282就进入共混步骤，因此阀266打开，从而允许进料流在吸附床281和282之间均匀分流。在共混步骤中的一定时间量之后，吸附床切换，并且现在吸附床281在吸附步骤中为在线的且吸附床282经历再生步骤。
如上所提及，根据本发明进行的空气分离过程优选地使用高纯度氧废物流作为变温吸附预纯化单元的再生气体来进行。使用纯度大于90％的氧流对吸附床的此类再生尚未在现有技术空气分离设备中使用。然而，本发明允许仅使用高纯度氧作为再生气体，其中再生气体的温度限于450℉或更优选地400℉，因此允许从空气分离设备得到总体更高的氮回收率。更高的氮回收率在更低资本成本和更低操作成本两方面改善了制氮空气分离设备的成本效率。例如，尺寸被设定为在中压下产生3000mcfh高纯度氮并且具有98.0％氮回收率的本发明制氮空气分离设备将需要必须被压缩、预纯化、冷却和精馏的3925mcfh进料空气。另一方面，尺寸被设定成在中压下产生3000mcfh的高纯度氮并且具有94.6％的氮回收率的现有技术的产氮空气分离设备(如美国专利号4,822,395中所述的)将需要4066mcfh的进料空气，该进料空气必须被压缩、预纯化、冷却和精馏。操作现有技术制氮空气分离设备的增加的成本可包括压缩体积流量增加的进入的进料空气的附加功率、预纯化更高流量的进入的进料空气所需的附加吸附材料，以及处理体积增加的进入的进料空气可能需要的涡轮机械、换热器、后冷却器、预纯化器、塔内部等的可能增加的资本设备成本。
此处应当注意，尽管本文讨论了水蒸气和二氧化碳去除，但是应当理解，也将通过一种或多种吸附剂来去除其他杂质，例如一氧化二氮、乙炔和其他痕量烃类。然而，水蒸气和二氧化碳以比此类其他杂质高得多的浓度存在，因此将对所需的吸附剂量具有最大影响。另外，虽然上述讨论适合变温吸附预纯化器，但本发明的教导内容和范围也可适用于一些混合预纯化器布置。
实施例
下面的表2和表3示出了分别针对以上参考图1和图2示出和描述的本发明的系统和方法的基于计算机的过程模拟的结果。出于比较目的，还包括对来自现有技术的Cheung系统的对应流和数据的参考，而表4提供了来自Cheung现有技术的系统和方法的可比较数据。表5比较了本发明系统的所选择的实施方案的氩回收率和氮回收率，并且比较了Cheung现有技术系统中的氩回收率和氮回收率。在针对图1的实施方案的模拟运行中，富氧液体流的纯度为99.6％，并且泵送液氧产物的流量为总进入空气进料的2.1％(或10％的可用氧)，而在针对图2的实施方案的模拟运行中，第二富氧液体流的纯度为93.7％，并且泵送液氧产物的流量也为总进入空气进料的15.5％。
流参考 Cheung中的参考 流量 压力 温度 ％氧 ％氮 ％氩
22(图1) N/A 100％ 14.7 294.3 21.0 78.1 0.9
29(图1) N/A 100％ 120.5 286.0 21.0 78.1 0.9
47(图1) 流10 89.6％ 118.3 108.5 21.0 78.1 0.9
36(图1) N/A 10.4％ 198.1 310.5 21.0 78.1 0.9
64(图1) 流23 8.3％ 32.9 110.3 21.0 78.1 0.9
90(图1) 40 28.4％ 131.0 98.8 99.6 0.0 0.4
190(图1) N/A 28.4％ 19.9 93.2 99.6 0.0 0.4
380(图1) 流26 2.1％ 33.1 98.7 99.6 0.0 0.4
390(图1) N/A 2.1％ 175.0 287.0 99.6 0.0 0.4
196(图1) 流41 18.9％ 19.9 93.16 99.5 0.0 0.5
290(图1) N/A 18.9％ 17.7 287.0 99.5 0.0 0.5
95(图1) 流25 77.1％ 31.7 84.5 <100ppb >99.98 <0.02
195(图1) N/A 78.1％ 31.1 103.5 <100ppb >99.98 <0.02
295(图1) N/A 78.1％ 29.4 287.0 <100ppb >99.98 <0.02
165(图1) 流32 0.8％ 34.8 96.3 <1ppm <1ppm >99.999
178(图1) N/A 0.006％ 31.8 88.6 ～100ppb 70.3 29.7
174(图1) N/A 1.0％ 31.7 85.7 <100ppb >99.98 <0.02
表2.
流参考 Cheung中的参考 流量 压力 温度 ％氧 ％氮 ％氩
22(图2) N/A 100％ 14.7 294.3 21.0 78.1 0.9
29(图2) N/A 100％ 115.5 286.0 21.0 78.1 0.9
47(图2) 流10 85.0％ 113.3 107.3 21.0 78.1 0.9
36(图2) N/A 15.0％ 188.1 310.5 21.0 78.1 0.9
64(图2) 流23 6.5％ 31.1 110.2 21.0 78.1 0.9
398(图2) 40 9.2％ 131.0 98.8 93.7 0.0 6.3
190(图2) N/A 9.2％ 19.9 92.9 93.7 0.0 6.3
380(图2) 流26 15.5％ 31.4 98.1 99.5 0.0 0.5
390(图2) N/A 7.3％ 175.0 287.0 99.5 0.0 0.5
196(图2) 流41 6.1％ 19.9 92.9 93.0 0.0 7.0
290(图2) N/A 14.1％ 17.7 287.0 96.6 0.0 3.4
95(图2) 流25 77.9％ 29.8 83.9 <100ppb >99.9 <0.1
195(图2) N/A 78.1％ 29.4 96.2 <100ppb >99.9 <0.1
295(图2) N/A 78.1％ 29.4 287.0 <100ppb >99.9 <0.1
165(图2) 流32 0.3％ 33.2 95.7 <1ppm <1ppm >99.999
178(图2) N/A 0.002％ 30.2 88.0 ～100ppb 70.7 29.3
174(图2) N/A 0.3％ 29.8 85.8 <100ppb >99.9 <0.01
表3.
Figure BDA0002730394830000211
表4.
Figure BDA0002730394830000212
Figure BDA0002730394830000221
表5.
*取决于所取得的高纯度泵送液氧产物(即，流386)的体积
**取决于所取得的高纯度泵送液氧产物(即，流386)的体积和第二富氧液体流(即，流398)的氧纯度
在美国专利号4,822,395(Cheung)中公开并在上表5中示出的气体回收表示冷箱回收，并且不考虑主换热器中或预纯化器床的再生中的潜在损失。表5提供了来自冷箱的Cheung中的公开氩回收率(92.7％)和来自整个空气分离单元的估计氩回收率(92.7％)。同样，表5还提供了来自冷箱的Cheung中的公开氮回收率(94.6％)和来自整个空气分离单元的估计氮回收率(91.6％)。此类估计是基于由Cheung编写的技术论文以及安装在现场的Cheung设备的实际实施方案。Cheung中的估计氮回收率表示在将一些氮与废物流共混以使废物流中的氧纯度降至80％(即，在空气分离设备的基于吸附的预纯化器单元的再生中的现有技术的氧水平)之后的可用作氮产物的剩余氮。
尽管已通过参照一个或多个优选实施方案以及相关联的方法讨论了用于从空气分离单元回收氩和氮的本发明系统，但是本领域的技术人员应当想到，在不脱离所附权利要求书描述的本发明的实质和范围的情况下，可对其进行多种改变和省略。

Claims (18)

1.一种空气分离单元，所述空气分离单元包括：
主空气压缩系统，所述主空气压缩系统被配置用于接收进入的进料空气流并且产生经压缩的空气流；
基于吸附的预纯化器单元，所述基于吸附的预纯化器单元被配置用于从所述经压缩的空气流去除水蒸气、二氧化碳、一氧化二氮和烃类并且产生经压缩并且纯化的空气流，其中所述经压缩并且纯化的空气流被分成至少所述经压缩并且纯化的空气流的第一部分和所述经压缩并且纯化的空气流的第二部分；
主换热系统，所述主换热系统被配置为冷却所述经压缩并且纯化的空气流的所述第一部分以产生蒸气空气流并且部分地冷却所述经压缩并且纯化的空气流的所述第二部分；
涡轮膨胀机布置，所述涡轮膨胀机布置被配置为使所述经压缩并且纯化的空气流的所述经部分冷却的第二部分膨胀以形成排气流，所述排气流向所述空气分离单元赋予制冷；
蒸馏塔系统，所述蒸馏塔系统包括具有介于6.0巴(a)和10.0巴(a)之间的操作压力的高压塔和具有介于1.5巴(a)和2.8巴(a)之间的操作压力的低压塔，所述高压塔和所述低压塔经由冷凝器-再沸器以热传递关系相连；
所述蒸馏塔系统还包括与所述低压塔操作性地联接的氩塔布置，所述氩塔布置具有至少一个氩塔和氩冷凝器；
所述蒸馏塔系统被配置为在所述高压塔中接收所述蒸气空气流的全部或一部分并在所述低压塔中接收所述排气流，并且产生来自所述低压塔的具有大于或等于99.5％氧的氧浓度的富氧流和来自所述低压塔的氮塔顶馏出物流；
其中所述氩塔被配置为从所述低压塔接收富氩-氧流，并且产生返回或释放到所述低压塔中的第三富氧塔底馏出物流以及被引导至所述氩冷凝器的富氩塔顶馏出物；
其中所述氩冷凝器被配置为依靠来自所述低压塔的所述富氧流的第一部分来冷凝所述富氩塔顶馏出物以产生粗制氩流或产物氩流、氩回流流和富氧废物流；
过冷器布置，所述过冷器布置与所述蒸馏塔系统操作性地联接并且被配置为经由与来自所述低压塔的所述氮塔顶馏出物流的间接换热来使来自所述高压塔的第四釜富氧流和来自所述冷凝器-再沸器的氮流过冷；并且
其中所述空气分离单元被配置为产生一种或多种高纯度氮产物；
其中所述空气分离单元被配置为回收大于75％的氩；并且
其中所述空气分离单元被配置为产生一种或多种氧产物，所述一种或多种氧产物包括来自所述低压塔的处于大于或等于3.4巴(a)的压力的高纯度泵送氧流。
2.根据权利要求1所述的空气分离单元，其中所述过冷器布置被进一步配置为经由与所述富氧废物流的间接换热来使来自所述低压塔的所述第二富氧流过冷。
3.根据权利要求1所述的空气分离单元：
其中所述基于吸附的预纯化器单元是被配置用于纯化所述经压缩的空气流的多床变温吸附单元，所述多床变温吸附单元被进一步配置为使得每个床在吸附来自所述经压缩的空气流的所述水蒸气、二氧化碳、一氧化二氮和烃类的在线操作阶段与其中所述床通过取自所述空气分离单元并且具有大于90.0％的氧含量的吹扫气体来再生的离线操作阶段之间交替；并且
其中所述空气分离单元被配置为产生一种或多种高纯度氮产物并且具有98％或更大的氮回收率。
4.根据权利要求3所述的空气分离单元，其中所述吹扫气体是所述富氧废物流。
5.根据权利要求4所述的空气分离单元，其中所述基于吸附的预纯化器单元还包括蒸汽加热器、电加热器或其他非燃烧式加热器，所述加热器被配置为将所述富氧废物流加热至小于或等于约450℉的温度以用于再生所述变温吸附单元中的所述吸附剂床。
6.根据权利要求1所述的空气分离单元，其中所述经压缩并且纯化的空气流的所述第二部分小于所述总经压缩并且纯化的空气流的约15％。
7.根据权利要求1所述的空气分离单元，其中所述蒸馏塔系统的所述低压塔被配置为主要接收共同具有小于15％蒸气的液体流。
8.根据权利要求1所述的空气分离单元，所述空气分离单元还包括增压压缩机，所述增压压缩机被配置为进一步压缩所述经压缩并且纯化的空气流的所述第二部分。
9.根据权利要求8所述的空气分离单元，其中所述涡轮膨胀机布置还包括增压器负载涡轮，所述增压器负载涡轮被配置为使所述经压缩并且纯化的空气流的所述经进一步压缩、部分冷却的第二部分膨胀以形成所述排气流，并且所述增压器负载涡轮被操作性地联接以驱动所述增压压缩机。
10.根据权利要求8所述的空气分离单元，其中所述过冷器布置被进一步配置为经由与所述富氧废物流的间接换热来使所述排气流过冷。
11.根据权利要求1所述的空气分离单元，其中所述氩塔被配置为在介于约1.3巴(a)和2.8巴(a)之间的压力下操作。
12.根据权利要求11所述的空气分离单元，其中所述氩塔布置中的所述氩塔是具有介于180和260个之间的分离级的超级塔或具有介于185和270个之间的分离级的极超级塔。
13.根据权利要求11所述的空气分离单元，其中所述氩塔布置还包括被配置为超级氩塔的第一氩塔、被配置为高比率氩塔的第二氩塔。
14.根据权利要求1所述的空气分离单元，所述空气分离单元还包括：
增压空气压缩机回路，所述增压空气压缩机回路联接到所述主换热器；
其中所述经压缩并且纯化的空气流分成所述经压缩并且纯化的空气流的所述第一部分、所述经压缩并且纯化的空气流的所述第二部分和所述经压缩并且纯化的空气流的第三部分；并且
其中增压空气压缩机回路被配置为将所述经压缩并且纯化的空气流的所述第三部分进一步压缩至超过所述主换热器中的所述泵送氧产物流压力的压力。
15.根据权利要求1所述的空气分离单元，其中所述一种或多种氧产物还包括来自离开所述主换热器的所述气化泵送氧流的气态氧产物流以及从来自所述低压塔的所述第一富氧流转移的液氧流。
16.根据权利要求1所述的空气分离单元，其中所述一种或多种氮产物还包括通过在所述过冷器布置和所述主换热器系统中加热所述氮塔顶馏出物流而产生的高纯度气态氮产物流，以及通过从所述冷凝器-再沸器转移所述过冷氮的一部分而产生的高纯度液体氮产物流。
17.根据权利要求1所述的空气分离单元，所述空气分离单元还包括：
再循环回路，所述再循环回路设置在所述氩冷凝器和所述低压塔之间并且被配置用于将液体富氧流从所述氩冷凝器引导至所述低压塔；
凝胶捕集器，所述凝胶捕集器以与所述再循环回路操作性地关联的方式设置，并且被配置为接收所述液体富氧流并从所述液体富氧流去除二氧化碳、一氧化二氮或其他污染物。
18.根据权利要求3所述的空气分离单元，所述空气分离单元还包括再生鼓风机，所述再生鼓风机被配置为将所述废物流的压力升高约0.1巴(a)至0.3巴(a)。
CN201980026675.4A 2018-04-25 2019-04-22 用于从产氮低温空气分离单元增强回收氩和氧的系统和方法 Active CN111989528B (zh)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US15/962297 2018-04-25
US15/962,297 US10663223B2 (en) 2018-04-25 2018-04-25 System and method for enhanced recovery of argon and oxygen from a nitrogen producing cryogenic air separation unit
PCT/US2019/028437 WO2019209672A2 (en) 2018-04-25 2019-04-22 System and method for enhanced recovery of argon and oxygen from a nitrogen producing cryogenic air separation unit

Publications (2)

Publication Number Publication Date
CN111989528A true CN111989528A (zh) 2020-11-24
CN111989528B CN111989528B (zh) 2021-08-27

Family

ID=66677203

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201980026675.4A Active CN111989528B (zh) 2018-04-25 2019-04-22 用于从产氮低温空气分离单元增强回收氩和氧的系统和方法

Country Status (6)

Country Link
US (1) US10663223B2 (zh)
EP (1) EP3784965A2 (zh)
KR (1) KR102258573B1 (zh)
CN (1) CN111989528B (zh)
CA (1) CA3097179C (zh)
WO (1) WO2019209672A2 (zh)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021230912A1 (en) 2020-05-11 2021-11-18 Praxair Technology, Inc. System and method for recovery of nitrogen, argon, and oxygen in moderate pressure cryogenic air separation unit
EP4150276A1 (en) 2020-05-15 2023-03-22 Praxair Technology, Inc. Integrated nitrogen liquefier for a nitrogen and argon producing cryogenic air separation unit
US11512897B2 (en) 2021-01-14 2022-11-29 Air Products And Chemicals, Inc. Fluid recovery process and apparatus
US11959701B2 (en) 2022-07-28 2024-04-16 Praxair Technology, Inc. Air separation unit and method for production of high purity nitrogen product using a distillation column system with an intermediate pressure kettle column
US20240035744A1 (en) 2022-07-28 2024-02-01 Neil M. Prosser Air separation unit and method for production of nitrogen and argon using a distillation column system with an intermediate pressure kettle column
US20240035743A1 (en) 2022-08-01 2024-02-01 Air Products And Chemicals, Inc. Process and apparatus for recovery of at least nitrogen and argon
US20240125550A1 (en) 2022-10-18 2024-04-18 Air Products And Chemicals, Inc. Process and Apparatus for Improved Recovery of Argon

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4575388A (en) * 1983-02-15 1986-03-11 Nihon Sanso Kabushiki Kaisha Process for recovering argon
US4822395A (en) * 1988-06-02 1989-04-18 Union Carbide Corporation Air separation process and apparatus for high argon recovery and moderate pressure nitrogen recovery
US5355681A (en) * 1993-09-23 1994-10-18 Air Products And Chemicals, Inc. Air separation schemes for oxygen and nitrogen coproduction as gas and/or liquid products
CN1206101A (zh) * 1997-07-18 1999-01-27 普拉塞尔技术有限公司 生产氩的柱结构和氩的生产方法
CN101018996A (zh) * 2003-12-24 2007-08-15 普莱克斯技术有限公司 用于生产高压氮的深冷系统
US20170030638A1 (en) * 2015-07-31 2017-02-02 Neil M. Prosser Method and apparatus for argon rejection and recovery

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5069698A (en) * 1990-11-06 1991-12-03 Union Carbide Industrial Gases Technology Corporation Xenon production system
US5133790A (en) 1991-06-24 1992-07-28 Union Carbide Industrial Gases Technology Corporation Cryogenic rectification method for producing refined argon
US5255522A (en) * 1992-02-13 1993-10-26 Air Products And Chemicals, Inc. Vaporization of liquid oxygen for increased argon recovery
US5440884A (en) * 1994-07-14 1995-08-15 Praxair Technology, Inc. Cryogenic air separation system with liquid air stripping
US5956973A (en) 1997-02-11 1999-09-28 Air Products And Chemicals, Inc. Air separation with intermediate pressure vaporization and expansion
US5802873A (en) * 1997-05-08 1998-09-08 Praxair Technology, Inc. Cryogenic rectification system with dual feed air turboexpansion
US6077488A (en) * 1998-03-19 2000-06-20 The Boc Group, Inc. Method and apparatus for producing clean dry air having application to air separation
US6106593A (en) * 1998-10-08 2000-08-22 Air Products And Chemicals, Inc. Purification of air
US6173586B1 (en) * 1999-08-31 2001-01-16 Praxair Technology, Inc. Cryogenic rectification system for producing very high purity oxygen
US7533540B2 (en) * 2006-03-10 2009-05-19 Praxair Technology, Inc. Cryogenic air separation system for enhanced liquid production
US7632337B2 (en) * 2006-06-30 2009-12-15 Praxair Technology, Inc. Air prepurification for cryogenic air separation
US20080223077A1 (en) * 2007-03-13 2008-09-18 Neil Mark Prosser Air separation method
US8286446B2 (en) * 2008-05-07 2012-10-16 Praxair Technology, Inc. Method and apparatus for separating air
US8443625B2 (en) 2008-08-14 2013-05-21 Praxair Technology, Inc. Krypton and xenon recovery method
US20120036891A1 (en) 2010-08-12 2012-02-16 Neil Mark Prosser Air separation method and apparatus
US9644890B2 (en) * 2013-03-01 2017-05-09 Praxair Technology, Inc. Argon production method and apparatus
US20160025408A1 (en) 2014-07-28 2016-01-28 Zhengrong Xu Air separation method and apparatus
US10012437B2 (en) * 2015-07-31 2018-07-03 Praxair Technology, Inc. Method and apparatus for argon recovery in a cryogenic air separation unit integrated with a pressure swing adsorption system
US10018413B2 (en) 2015-07-31 2018-07-10 Praxair Technology, Inc. Method and apparatus for increasing argon recovery in a cryogenic air separation unit integrated with a pressure swing adsorption system
AU2017318652A1 (en) * 2016-08-30 2019-03-07 8 Rivers Capital, Llc Cryogenic air separation method for producing oxygen at high pressures

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4575388A (en) * 1983-02-15 1986-03-11 Nihon Sanso Kabushiki Kaisha Process for recovering argon
US4822395A (en) * 1988-06-02 1989-04-18 Union Carbide Corporation Air separation process and apparatus for high argon recovery and moderate pressure nitrogen recovery
US5355681A (en) * 1993-09-23 1994-10-18 Air Products And Chemicals, Inc. Air separation schemes for oxygen and nitrogen coproduction as gas and/or liquid products
CN1206101A (zh) * 1997-07-18 1999-01-27 普拉塞尔技术有限公司 生产氩的柱结构和氩的生产方法
CN101018996A (zh) * 2003-12-24 2007-08-15 普莱克斯技术有限公司 用于生产高压氮的深冷系统
US20170030638A1 (en) * 2015-07-31 2017-02-02 Neil M. Prosser Method and apparatus for argon rejection and recovery

Also Published As

Publication number Publication date
US20190331419A1 (en) 2019-10-31
US10663223B2 (en) 2020-05-26
WO2019209672A3 (en) 2019-12-05
CA3097179A1 (en) 2019-10-31
EP3784965A2 (en) 2021-03-03
KR102258573B1 (ko) 2021-05-31
CN111989528B (zh) 2021-08-27
KR20200133801A (ko) 2020-11-30
WO2019209672A2 (en) 2019-10-31
CA3097179C (en) 2021-10-26

Similar Documents

Publication Publication Date Title
CN112005067B (zh) 用于从产氮低温空气分离单元增强回收氩和氧的系统和方法
CN112005068B (zh) 用于从中压低温空气分离单元实现氮和氩的高回收率的系统和方法
CN112041626B (zh) 用于从产氮低温空气分离单元增强回收氩和氧的系统和方法
CN111989528B (zh) 用于从产氮低温空气分离单元增强回收氩和氧的系统和方法
US10981103B2 (en) System and method for enhanced recovery of liquid oxygen from a nitrogen and argon producing cryogenic air separation unit
CN115461584A (zh) 用于从中压低温空气分离单元回收氮、氩和氧的系统和方法

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant