EP4702293A1 - Process and apparatus for air separation by cryogenic distillation - Google Patents

Process and apparatus for air separation by cryogenic distillation

Info

Publication number
EP4702293A1
EP4702293A1 EP24721922.3A EP24721922A EP4702293A1 EP 4702293 A1 EP4702293 A1 EP 4702293A1 EP 24721922 A EP24721922 A EP 24721922A EP 4702293 A1 EP4702293 A1 EP 4702293A1
Authority
EP
European Patent Office
Prior art keywords
oxygen
column
gas
heat exchanger
turbine
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.)
Pending
Application number
EP24721922.3A
Other languages
German (de)
French (fr)
Inventor
Kenji Hirose
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.)
Air Liquide SA
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Original Assignee
Air Liquide SA
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
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
Priority claimed from JP2023070607A external-priority patent/JP7355980B1/en
Application filed by Air Liquide SA, LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude filed Critical Air Liquide SA
Priority claimed from PCT/EP2024/060946 external-priority patent/WO2024223491A1/en
Publication of EP4702293A1 publication Critical patent/EP4702293A1/en
Pending legal-status Critical Current

Links

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
    • F25J3/04248—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
    • F25J3/04321—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 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
    • F25J3/04248—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
    • F25J3/04406—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
    • F25J3/04521—Coupling of the air fractionation unit to an air gas-consuming unit, so-called integrated processes
    • F25J3/04612—Heat exchange integration with process streams, e.g. from the air gas consuming unit
    • 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
    • F25J3/04636—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 hybrid air separation unit, e.g. combined process by cryogenic separation and non-cryogenic separation techniques
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04642—Recovering noble gases from air
    • F25J3/04648—Recovering noble gases from air argon
    • F25J3/04654—Producing crude argon in a crude argon column
    • F25J3/04666—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system
    • F25J3/04672—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system having a top condenser
    • F25J3/04678—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system having a top condenser cooled by oxygen enriched liquid from high pressure column bottoms
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/08—Separating gaseous impurities from gases or gaseous mixtures or from liquefied gases or liquefied gaseous mixtures
    • 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
    • F25J2200/02—Processes or apparatus using separation by rectification in a single 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
    • F25J2200/54—Processes or apparatus using separation by rectification using multiple (re-)boiler-condensers at different heights of the column in the low pressure column of a double 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
    • F25J2200/72—Refluxing the column with at least a part of the totally 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
    • F25J2205/00—Processes or apparatus using other separation and/or other processing means
    • F25J2205/86—Processes or apparatus using other separation and/or other processing means using electrical phenomena, e.g. Corona discharge, electrolysis or magnetic field
    • 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
    • F25J2210/50—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
    • F25J2215/00—Processes characterised by the type or other details of the product stream
    • F25J2215/04—Recovery of liquid products
    • 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
    • F25J2215/50—Oxygen or special cases, e.g. isotope-mixtures or low purity O2
    • F25J2215/56—Ultra high purity oxygen, i.e. generally more than 99,9% 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
    • F25J2220/00—Processes or apparatus involving steps for the removal of impurities
    • F25J2220/50—Separating low boiling, i.e. more volatile components from oxygen, e.g. N2, Ar
    • 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
    • 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
    • F25J2270/14—External 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
    • F25J2270/14—External refrigeration with work-producing gas expansion loop
    • F25J2270/16—External refrigeration with work-producing gas expansion loop with mutliple gas expansion loops of the same refrigerant

Landscapes

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

Abstract

In an air separation process by cryogenic distillation, at least part of the cold necessary for the process is supplied by expansion in at least one turbine (92) of a gas (5) containing at least 95% oxygen at a pressure of at least 2 bars abs which comes from an external source and is cooled in a heat exchanger (12) of the air separation process, together with the feed air (1).

Description

Process and apparatus for air separation by cryogenic distillation
The present invention relates to a process and an apparatus for separating air by cryogenic distillation.
An air separation process by cryogenic distillation requires a source of refrigeration, which can be the expansion of air or nitrogen produced by the separation or otherwise the addition of a cryogenic liquid from an external source. It is known from GB1576910 to expand oxygen enriched gas coming from a low pressure column of a double air separation column in an expansion turbine to provide cold for the process.
It has also been known for decades to produce hydrogen by electrolysis of water using electrical energy. This electrolysis also generates oxygen gas under pressure.
One aim of the present invention is to valorize this by-product of electrolysis by producing cold for an air separation apparatus by cryogenic distillation. Since the goal of electrolysis is to produce hydrogen, oxygen may not meet demand or be in surplus. If the oxygen produced is insufficient, the presence of an air separation device can make up for this lack of oxygen produced by electrolysis.
It is therefore interesting to find a solution integrating the production of oxygen by electrolysis and the production of oxygen by cryogenic distillation.
The present invention relates to a method of utilizing oxygen from an external source by sending it into the main exchanger to cool against fluids produced by cryogenic air separation. This oxygen is then expanded in a turbine and returned to the main heat exchanger. Thus the cold usually obtained by expansion of air or nitrogen is provided by this means and in certain cases, no air or nitrogen turbine may be required. In addition, the energy efficiency of the process is improved.
The term "main heat exchanger" here refers to a device in which the supply air is cooled approximately to the dew point.
The main heat exchanger can consist of several blocks connected in parallel and/or series.
The electrolysis of water forms a stream of hydrogen and a stream of oxygen. The hydrogen is supplied as a hydrogen product.
The oxygen from an electrolysis process contains water due to the production process and is therefore purified to remove of water and other components (eg hydrogen, carbon monoxide) in a purifier.
The purifier consists, for example, of at least two beds of adsorbents, which operate alternately
According to one object of the invention, there is provided a process for separating air by cryogenic distillation in which i) A flow of air is dried, purified of CO2, cooled in a heat exchanger and separated in a column system comprising at least one distillation column operating at a cryogenic temperature to form at least one fluid enriched in oxygen relative to air and at least one fluid enriched in nitrogen relative to air, ii) The at least one fluid enriched in oxygen or nitrogen is warmed in the heat exchanger, iii) At least part of the cold necessary for the process is provided by expansion in a turbine of a gas containing at least 95 mol% oxygen at a pressure of at least 2 bars abs which comes from an external source, the gas being cooled down to at least an intermediate temperature of the heat exchanger, withdrawn from the heat exchanger, expanded in the turbine and is warmed in the heat exchanger.
According to other optional aspects:
• The external source is a water electrolyzer.
• The gas containing at least 95 mol% oxygen has been expanded from a pressure of at least 4 bars abs, preferably at least 10 bars abs.
• The gas containing at least 95 mol% oxygen is not compressed between the external source and the turbine.
• The column system includes a first column operating at a first pressure and a second column operating at a second pressure lower than the first pressure, the head of the first column being thermally connected to the bottom of the second column.
• The column system includes a first column operating at a first pressure and a second column operating at a second pressure lower than the first pressure, the head of the first column being thermally connected to the bottom of the second column, the second column having a top condenser fed by a bottom liquid of the second column.
• The turbine also expands a flow containing at least 93% mol oxygen from the second column.
• The gas expanded in the turbine is mixed with a flow containing at least 93% mol oxygen from a column of the column system, for example from the second column, forming a mixture and the mixture is heated in the heat exchanger.
• The gas expanded in the turbine is mixed with a flow containing at least 93% mol oxygen from the second column forming a mixture and the mixture is expanded in a second turbine forming an expanded mixture which is heated in the heat exchanger.
• No flow of air or nitrogen gas is expanded in a turbine to provide cold to the process.
• No flow of cryogenic liquid is sent to the process from an external source.
• The process produces liquid oxygen and/or liquid nitrogen as a final product.
• The heat exchanger has one end operating at a first temperature and one end operating at a second temperature lower than the first temperature, the intermediate temperature being between the first and second temperatures.
• The gas expanded in the turbine is introduced into the heat exchanger at the end operating at the second temperature.
• The gas expanded in the turbine is expanded upstream of the turbine in a valve.
• The gas comprising at least 95 mol% oxygen is the only gas expanded in the turbine.
• The column system includes a column having an overhead condenser and a nitrogen enriched gas is withdrawn at the top of the column.
• The column system includes a column having a bottom reboiler, heated by bottom liquid from the column having an overhead condenser.
• The gas containing at least 95 mol% oxygen is sent to a plurality of first passages of the heat exchanger to cool, at least some of the first passages being adjacent to at least one passage where air is cooled and /or at least one passage where gaseous nitrogen coming from the column system is heated, the air and/or the gaseous nitrogen being at a pressure greater than that of the gas containing at least 95% mol of oxygen which cools down.
• The expanded gas containing at least 95 mol % oxygen is sent to a plurality of second passages of the heat exchanger to warm, at least some of the second passages being adjacent to at least one passage where air is cooled and/or at least one passage where nitrogen gas coming from the column system is warmed, the air and/or the nitrogen gas being at a pressure greater than that of the gas containing at least 95 mol% oxygen which warms up.
• the gas is cooled down to a cold end of the heat exchanger, withdrawn from the heat exchanger, liquefied to form a two phase mixture, the gaseous part of which is expanded in the turbine and is warmed in the heat exchanger.
• the gas containing at least 95 mol% oxygen is purified from water upstream of the heat exchanger.
• The gas containing at least 95 mol% oxygen is divided, one fraction being sent to the at least one turbine and the rest to an oxygen purification column 5
Alternatively a first stream containing at least 95 mol% oxygen from an external source is sent to the at least one turbine to be expanded and a second stream containing at least 95 mol% oxygen from the external source or another external source (for example another electrolyser) is sent to be purified in a distillation column.
The first and second streams may have different compositions and/or different pressures and/or different temperatures and/or may originate from different external sources, both of which may be electrolysers.
In this way, it is possible to treat oxygen having different characteristics in a single air separation unit.
According to a further object of the invention, there is provided an air separation apparatus using cryogenic distillation comprising a heat exchanger, a column system comprising at least one distillation column capable of operating at a cryogenic temperature, a conduit for sending an air flow is dried, purified of CO2, to be cooled in the heat exchanger, a conduit for sending the cooled air flow to be separated in the column system comprising at least one distillation column operating at a cryogenic temperature to form at least a fluid enriched in oxygen relative to air and at least one fluid enriched in nitrogen relative to air, a conduit for sending the at least one fluid enriched in oxygen or nitrogen to be warmed in the heat exchanger, at least one turbine, a conduit for sending a gas containing at least 95% oxygen at a pressure of at least 2 bars which comes from an external source to the heat exchanger to be cooled to an intermediate temperature of the heat exchanger, a conduit for sending the gas at the intermediate temperature to the at least one turbine to be expanded and a conduit for sending the expanded gas from the turbine to the heat exchanger to be warmed.
Preferably the apparatus comprises a conduit for sending a stream containing oxygen from the column system to the at least one turbine to be expanded with the gas containing at least 95% oxygen.
The column system may include an oxygen purification column.
Preferably the apparatus comprises a conduit for sending a gas containing at least 95% oxygen which comes from an external source to be separated in the oxygen purification column forming a purified oxygen stream.
The apparatus may further comprise a conduit for sending the purified oxygen stream to be mixed with the expanded gas from the at least one turbine and a conduit for sending the mixed gas to the heat exchanger. Otherwise the purified oxygen stream can be warmed separately in the heat exchanger, if desired.
The invention will be described in more detail with reference to the figures where: [FIG.1 ], [FIG.2], [FIG.3], [FIG.4], [FIG.5] and [FIG.6] represent processes according to the invention.
[FIG.1 ] represents a process according to the invention for which refrigeration is provided by a flow of oxygen 5 containing at least 95% mol of oxygen from an external source, for example a water electrolyzer also producing a flow of hydrogen. The oxygen pressure is at least 5 bars abs, or even at least 10 bars abs and preferably has not been compressed downstream of the external source. On the other hand, if it contains water, it must be dried upstream of exchanger 12.
Air 1 dried and purified of CO2 is sent to a hot end of a main heat exchanger at a temperature of 20.0°C, a pressure of 9.9 barA, and a flow rate of 962 Nm3/h, cooled in the main exchanger 12 down to -163.3°C and/or its dew point and sent via line L1 into a separation column 2 operating at a first pressure. The column system of the air separation apparatus comprises column 2 and a column 4 operating at a second pressure lower than the first pressure. Column 2 has an overhead condenser 3 heated by nitrogen from column 2 to vaporize liquid oxygen from the bottom of column 4. Air 1 separates in column 2 forming an oxygen-enriched liquid in the bottom and a liquid enriched with nitrogen at the top. These two liquids are sent to column 4.
52 Nm 3/h of nitrogen-enriched liquid from the head of column 2 are cooled to -179°C in a subcooler 8 and then sent to the top of column 4. The gaseous nitrogen 19 accumulated at the top of the column 2 is drawn off as a product with a flow rate of 350 Nm 3/h, heated up to 20.0°C in heat exchanger 12 and produced at a pressure of at least 8 barA, which is that of column 2. At the bottom of column 2, an oxygen-enriched liquid containing approximately 35.8 mol% is withdrawn with a flow rate of 564 Nm 3 /h, cooled to -169°C in subcooler 8 and then sent to the middle of column 4.
Column 4 includes an overhead condenser 23, which condenses the nitrogen gas at the top of the column and returns it to the top of column 4. The overhead gas is withdrawn as a second product rich in nitrogen 17 with a flow rate of 349 Nm3 /h. After reheating in the subcooler, it is heated up to 19.0°C in the heat exchanger 12 and is produced at a pressure 4.1 barA corresponding to the pressure of column 4. In the bottom of column 4, an enriched liquid 13 in oxygen containing 75.5 mol% of oxygen is withdrawn with a flow rate of 267 Nm /h, cooled to -179°C in subcooler 8 and then sent to the overhead condenser of column 4 for cooling. The liquid is vaporized in the condenser to produce an oxygen-enriched gas which is reheated in the subcooler 8, heated to 19°C in the exchanger and produced at a pressure of 1 .2 barA.
The oxygen-rich gas 5 containing at least 95 mol% oxygen is introduced into the hot end of the heat exchanger 12 at a temperature of 35°C, a pressure of at least 2 barsA, or at least 4 barA or even at least 10 barA, and a flow rate of 46 Nm 3 /h, cooled to - 75°C which is an intermediate temperature of the exchanger 12, leaves the exchanger 12 and is expanded up to 1.28 barA in an expansion turbine 92, cooled to -152° C by the expansion and is reintroduced into the heat exchanger 12 at the cold end. This expanded oxygen can be mixed with a waste gas. It will be noted that the process does not include any air turbine or any nitrogen turbine.
In addition there is no sending of cryogenic liquid to any column from an external source.
An improvement in energy efficiency of around 3% is noted.
In the variant of Figure 2, the column system comprises a first column 2 operating at a first pressure and a second column 4 operating at a second pressure lower than the first pressure. Columns 2, 4 are thermally connected by a condenser 3 which condenses nitrogen overhead from column 2 against liquid oxygen from the bottom of column 4.
The column system of the air separation apparatus comprises column 2 and a column
4 operating at a second pressure lower than the first pressure. Column 2 has an overhead condenser 3 heated by nitrogen from column 2 to vaporize liquid oxygen from the bottom of column 4. Air 1 separates in column 2 forming an oxygen-enriched liquid in the bottom and a liquid enriched with nitrogen at the top. These two liquids are at least partly sent to column 4.
The process produces liquid oxygen LOX at the bottom of column 4 and liquid nitrogen LIN at the top of column 4 as products for export. No flow of nitrogen gas is withdrawn at the top of column 2 and column 4 does not include an overhead condenser.
According to this variant, a flow of gaseous oxygen 15 is drawn off above the liquid accumulated in the bottom of column 4 and is mixed with the oxygen expanded from at least 2 barsA, or at least 4 barA or even at least 10 barA in the turbine 92, the mixture formed being warmed in the heat exchanger 12 from the cold end.
In the variant of Figure 3, based on Figure 2, the oxygen 5 is expanded in two stages. In turbine 92, it is the only expanded flow. It is expanded from at least 4 barA, at least
5 barA or possibly at least 10 barA down to the pressure of column 4 which is greater than atmospheric pressure and is operated at around 2 to 5 barsA, preferably 2,5 to 4,5 barA. Then the oxygen expanded in the turbine 92 is mixed with the oxygen 15 and the mixture 16 is expanded to a pressure slightly above atmospheric pressure in the turbine 102.
In this case, oxygen 5 must be at a minimum pressure of 4 barA, possibly at least barsA. The device includes an argon column 6 which produces gaseous argon Ar, the head condenser of which is supplied with a fraction of the liquid enriched in oxygen.
It will be understood that Figure 2 can also include an argon column.
An oxygen production apparatus A3 will be described with the aid of fig. 4.
The oxygen production apparatus A3 includes an air separation unit comprising: a main heat exchanger 1 , a rectification column 2 operating at a first pressure, a nitrogen condenser 3, a rectification column 4 operating at a second pressure lower than the first pressure, an expansion turbine 92, an oxygen rectification column 50, an oxygen vaporizer 6, and a sub-cooler 8.
Feed air and feed oxygen are introduced into the main heat exchanger 12 from a warm end thereof and drawn from a cold end thereof, while product nitrogen gas and waste gas are introduced from the cold end thereof and drawn from the warm end thereof. Predetermined impurities and moisture are removed from the feed air upstream of the heat exchanger 12. The feed oxygen is oxygen containing at least 95% mol oxygen, for example by-product oxygen from water electrolysis, and contains low-boiling-point components (e.g., nitrogen and argon) as impurities. The oxygen concentration of the feed oxygen may be greater than 99.9% mol, for example 99.99%.
In order to remove the low-boiling-point components in the oxygen by cryogenic separation, part of the oxygen is liquefied in heat exchanger 12 and then passes via conduit L10 to an expansion valve and is expanded and sent to an intermediate region of the oxygen column 50. There the oxygen is the only feed stream to the column 5. It undergoes heat and substance exchange with a vapour stream containing oxygen inside the rectification column 50 so that the low-boiling-point components are removed while oxygen is concentrated in the liquid phase.
The medium-pressure rectification column 2 comprises: a bottom portion 21 into which the feed air cooled in the main heat exchanger 1 is introduced, a rectification portion 22, and a column top 23. A feed air pipeline L1 is a pipeline for introducing the feed air, via the main heat exchanger 1 , into a gas phase in the bottom portion 21 of the mediumpressure rectification column 2, or into a lower portion of a purification portion 22. A first oxygen rich liquid pipeline L21a is a pipeline for introducing, into an intermediate stage of a rectification portion 42 of the low-pressure rectification column 4, via the sub-cooler 8, an oxygen-enriched liquid drawn from the bottom portion 21 of the medium-pressure rectification column 2. The first oxygen-enriched liquid pipeline L21 a and a second oxygen-enriched liquid pipeline L21 b may branch from a main pipeline L21 for the oxygen-enriched liquid. A condensing pipeline L23 is a pipeline which delivers, to the nitrogen condenser 3, a nitrogen-rich gas drawn from the column top 23 of the mediumpressure rectification column 2, and which merges with a first reflux liquid pipeline L231 leading out from the column top 23. The first reflux liquid L231 is a pipeline for introducing, into a column top 43 of the low-pressure rectification column 4, via the subcooler 8, a nitrogen-rich liquid drawn from the column top 23 of the medium-pressure rectification column 2.
The nitrogen condenser 3 condenses a nitrogen-rich gas drawn from the column top 23 of the medium-pressure rectification column 2. A first waste gas pipeline L31 is a pipeline for causing an oxygen enriched gas, which is drawn from the gas phase in the nitrogen condenser 3, to pass through a part of the main heat exchanger 12, the gas then being used in the expansion turbine 92, and once again passed through the main heat exchanger 12.
The low-pressure rectification column 4 has the column top 43 and the rectification portion 42 into which is introduced a nitrogen-rich liquid condensed in the nitrogen condenser 3 and/or a nitrogen-rich liquid drawn from the column top 23 of the mediumpressure rectification column 2, after said nitrogen-rich liquid has been cooled in the sub-cooler 8. A product nitrogen gas pipeline L43 is a pipeline for causing the nitrogen- rich gas drawn from the column top 43 of the low-pressure rectification column 4 to pass through the main heat exchanger 12, via the sub-cooler 8.
An oxygen rich gas drawn from a gas phase above the nitrogen condenser 3 is introduced into the expansion turbine 92 after said gas has been passed through a part of the main heat exchanger 1 . After being used in the expansion turbine 92, the gas is once again delivered to the main heat exchanger 12 from where it is drawn out.
The oxygen rectification column 50 has a column top 53 or a purification portion 52 into which the feed oxygen that has undergone heat exchange in the main heat exchanger 1 is introduced. A feed oxygen pipeline L10 is a pipeline for introducing the feed oxygen, via the main heat exchanger 1 , into the column top 53 or the rectification portion 52 of the oxygen rectification column 5. A second pipeline L53 is a pipeline for causing low- boiling-point component-containing oxygen gas, which is drawn from the column top 53 of the oxygen rectification column 50, to merge into the pipeline L31 downstream from the expansion turbine 92 and upstream from the main heat exchanger 1 .
The oxygen vaporizer 6 is arranged below a bottom portion 51 of the oxygen rectification column 5 and vaporizes liquefied oxygen while using, as a heating medium, an oxygen-enriched liquid drawn from the bottom portion 21 of the medium-pressure rectification column 2. The second oxygen-enriched liquid pipeline L21 b is a pipeline for introducing the oxygen-enriched liquid drawn from the bottom portion 21 of the medium-pressure rectification column 2 into the oxygen vaporizer 6, from where it is introduced into an intermediate stage of the rectification portion 42 of the low-pressure rectification column 4. An ultra-high-purity oxygen extraction pipeline L61 is a pipeline for extracting u Itra-h igh-purity oxygen (liquid) from a vaporized liquid portion 61 of the oxygen vaporizer 6.
The oxygen vaporizer 6 is arranged below the oxygen rectification column 5 in order to supply a vapour stream to the oxygen rectification column 5. The oxygen vaporizer 6 vaporizes liquefied oxygen supplied from the bottom portion 51 of the oxygen rectification column 50 and supplies the vapour stream thereof to the bottom portion 51 of the oxygen rectification column 50. As another embodiment, a portion of the feed air supplied from the main heat exchanger 1 , or a portion of an oxygen-containing liquid or liquefied nitrogen supplied from the medium-pressure rectification column 2 may be utilized to reboil column 50.
The gas which is used as the heating medium may be liquefied and used as a reflux liquid in the low-pressure rectification column 4, or as a refrigerant in the main heat exchanger 1 or the sub-cooler 8. The liquid which is used as the heating medium is sub-cooled, and therefore vaporization loss during decompression is reduced.
The sub-cooler 8 performs heat exchange of: an oxygen-rich liquid drawn from the bottom portion 21 of the medium-pressure rectification column 2, a purified gas condensed in the nitrogen condenser 3 and/or a purified gas drawn from the column top 23 of the medium-pressure rectification column 2, and a nitrogen-rich gas drawn from the column top 43 of the low-pressure rectification column 4. The apparatus A3 comprises a branch feed oxygen pipeline L11. The branch feed oxygen pipeline L11 takes a fraction of the feed oxygen which is partially cooled in the main heat exchanger 12 branched off from feed oxygen pipeline L10. The fraction merges into the first waste gas pipeline L31 before connection to the expansion turbine 92.
It will be appreciated that whilst the feed oxygen stream is here shown as being divided, one fraction being sent to turbine 92 and the rest to the oxygen purification column 50, it is possible to have two separate feed oxygen streams, one of which is sent to turbine 92 and the other of which is sent to the column 5. In this case, the two streams may have different compositions and/or different pressures and/or different temperatures and/or may originate from different external sources, both of which may be electrolysers.
Figure 5 differs from Figure 4 in that the oxygen gas L53 with an increased concentration of light impurities is sent to be expanded in turbine 92, the pressure of column 50 being sufficiently high.
Figure 6 shows a process in which a flow 5 of oxygen produced, for example, by electrolysis and optionally purified to remove hydrogen and/or carbon monoxide, is liquefied within an air separation apparatus by cryogenic distillation.
The air 1 is cooled in the heat exchanger 12 and sent to the first column 2 operating at a first pressure. A nitrogen-enriched liquid and an oxygen-enriched liquid are sent from the first column 2 to the second column 4. An oxygen-rich flow 15 is withdrawn from the second column 4, operating at a second pressure pressure than the first pressure. This flow 15 is expanded in a turbine 92 to form an expanded flow.
The flow of oxygen 5 produced by electrolysis is liquefied by indirect heat exchange with at least one gas separated from air which warms in the heat exchanger heat exchanger 12, forming a two-phase mixture after expansion in a valve. Flow 5 is not mixed with the feed air 1 .
This gas separated from air may be nitrogen 15 coming from the second column 4 after reheating in the sub-cooler 8. The two phase mixture is stored in a storage tank T forming a liquid LOX and an overhead gas 55. At least part of the overhead gas 55 is mixed with the oxygen rich gas 15 from the column 4 without having been warmed in the heat exchanger and the mixture is expanded in the turbine 92 to form an expanded flow which heats up in the heat exchanger 12. It will be understood that Figure 2 may also include an argon column.
This process makes it possible to liquefy a flow of oxygen 5 from an electrolyser which is surplus to existing requirements and to use the gas 55 formed by condensing stream 5 to produce refrigeration.
If necessary, the gas 55 can be the only gas expanded in the turbine. For example, the expanded gas 55 can be expanded in turbine 92, mixed with gas 55 or L53 from Figures 4 and 5 and expanded in another turbine.
To reduce security concerns, for all figures:
• The gas 5 containing at least 95 mol% oxygen is sent to a plurality of first passages of the heat exchanger 12 to cool, at least some of the first passages being adjacent to at least one passage where the air 1 cools and/or at least one passage where nitrogen gas 17, 19 coming from the system of columns 2, 4 is heated, the air and/or the nitrogen gas being at a pressure greater than that of the gas containing at least 95%mol of oxygen which cools
If the expanded gas is not mixed with another gas, the expanded gas 5 containing at least 95 mol% oxygen is sent to a plurality of second passages of the heat exchanger 12 to reheat, at least some of the second passages being adjacent to at least one passage where air 1 cools and/or to at least one passage where gaseous nitrogen 17, 19 coming from the column system warms, air and/or nitrogen gas being at a pressure higher than that of the gas containing at least 95 mol% oxygen which warms.
If the expanded gas is mixed with another gas 15, L53, the gas mixture 16 is sent to a plurality of second passages of the heat exchanger 12 to warm, at least some of the second passages being adjacent to at least one passage where air 1 cools and/or at least one passage where nitrogen gas 17, 19 coming from the column system is heated, the air and/or the nitrogen gas being at a pressure greater than that of the mixture 16 which warms.

Claims

Claims
1 . Air separation process by cryogenic distillation in which: i) An air flow (1 ) is dried, purified of CO2, cooled in a heat exchanger (2) and separated in a column system (2, 4, 50) comprising at least one distillation column operating at a cryogenic temperature to form at least a fluid enriched in oxygen (15) relative to air and at least one fluid enriched in nitrogen (19) relative to air ii) The at least one fluid enriched in oxygen or nitrogen heats up in the heat exchanger and iii) At least part of the cold necessary for the process is supplied by expansion in at least one turbine (92, 102) of a gas (5, 55) containing at least 95% mol oxygen at a pressure of at least 2 bars which comes from an external source, is cooled to at least an intermediate temperature of the heat exchanger, is expanded in the at least one turbine and is reheated in the heat exchanger.
2. Process according to Claim 1 wherein the external source is a water electrolyzer.
3. Process according to Claim 1 or 2 wherein the gas containing at least 95 mol% oxygen (5, 55) is expanded from a pressure of at least 4 bars abs in the at least one turbine (92, 102).
4. Process according to any preceding claim wherein the gas containing at least 95 mol% oxygen (5, 55) is not compressed between the external source and the turbine (92, 102).
5. Process according to any preceding claim wherein the column system includes a first column (2) operating at a first pressure and a second column (4) operating at a second pressure lower than the first pressure, the head of the first column being thermally connected to the bottom of the second column.
6. Process according to any preceding claim wherein the column system includes a first column operating at a first pressure (2) and a second column operating at a second pressure (4) lower than the first pressure, the head of the first column being thermally connected to the bottom of the second column, the second column having a top condenser (23) fed by a bottom liquid (13) of the second column.
7. Process according to any preceding claim wherein the turbine (92, 102) also expands a flow (15) containing at least 93% mol oxygen from the second column (4).
8. Process according to any preceding claim wherein the gas (5) expanded in the turbine (92, 102) is mixed with a flow (15, L53) containing at least 93% mol oxygen from a column (4, 50) of the column system forming a mixture (16) and the mixture is heated in the heat exchanger (12).
9. Process according to any preceding claim wherein the gas (5) expanded in the turbine (92) is mixed with a flow (15) containing at least 93% mol oxygen from the second column forming a mixture (16) and the mixture is expanded in a second turbine (102) forming an expanded mixture which is heated in the heat exchanger (12).
10. Process according to any preceding claim wherein the heat exchanger (12) has one end operating at a first temperature and one end operating at a second temperature lower than the first temperature, the intermediate temperature being between the first and second temperatures, the gas (5, 16) expanded in the at least one turbine (92, 102) entering the heat exchanger at the end operating at the second temperature.
11 . Process according to any preceding claim wherein the gas containing at least 95 mol% oxygen (5) is sent to a plurality of first passages of the heat exchanger (12) to cool, at least some of the first passages being adjacent to at least one passage where air (1 ) is cooled and /or at least one passage where gaseous nitrogen (17) coming from the column system is heated, the air and/or the gaseous nitrogen being at a pressure greater than that of the gas containing at least 95% mol of oxygen which cools down.
12. Process according to any preceding claim wherein the expanded gas containing at least 95 mol % oxygen (5, 16) is sent to a plurality of second passages of the heat exchanger (12) to warm, at least some of the second passages being adjacent to at least one passage where air (1 ) is cooled and/or at least one passage where nitrogen gas (17) coming from the column system is warmed, the air and/or the nitrogen gas being at a pressure greater than that of the gas containing at least 95 mol% oxygen which warms up.
13. Air separation apparatus using cryogenic distillation comprising a heat exchanger (2), a column system (2, 4) comprising at least one distillation column capable of operating at a cryogenic temperature, a conduit for sending an air flow (1 ) is dried, purified of CO2, to be cooled in the heat exchanger (2), a conduit (L1 ) for sending the cooled air flow to be separated in the column system (2, 4) comprising at least one distillation column operating at a cryogenic temperature to form at least a fluid enriched in oxygen (15) relative to air and at least one fluid enriched in nitrogen (19) relative to air, a conduit (L31 , L43) for sending the at least one fluid enriched in oxygen or nitrogen to be warmed in the heat exchanger, at least one turbine (92, 102), a conduit for sending a gas (5) containing at least 95% oxygen at a pressure of at least 2 bars which comes from an external source to the heat exchanger to be cooled to an intermediate temperature of the heat exchanger, a conduit for sending the gas at the intermediate temperature to the at least one turbine to be expanded and a conduit for sending the expanded gas from the turbine to the heat exchanger to be warmed.
14. Apparatus according to Claim 13 comprising a conduit for sending a stream (15) containing oxygen from the column system to the at least one turbine (102) to be expanded with the gas (5) containing at least 95% oxygen.
15. Apparatus according to Claim 14 wherein the column system includes an oxygen purification column (50), a conduit for sending a gas (5) containing at least 95% oxygen which comes from an external source to be separated in the oxygen purification column forming a purified oxygen stream, a conduit for sending the purified oxygen stream (L53) to be mixed with the expanded gas from the at least one turbine and a conduit for sending the mixed gas to the heat exchanger.
EP24721922.3A 2023-04-24 2024-04-22 Process and apparatus for air separation by cryogenic distillation Pending EP4702293A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2023070607A JP7355980B1 (en) 2023-04-24 2023-04-24 Ultra-high purity oxygen production method and ultra-high purity oxygen production equipment
FR2400965A FR3150578B3 (en) 2023-04-24 2024-01-31 Process and apparatus for air separation by cryogenic distillation
FR2401265 2024-02-09
PCT/EP2024/060946 WO2024223491A1 (en) 2023-04-24 2024-04-22 Process and apparatus for air separation by cryogenic distillation

Publications (1)

Publication Number Publication Date
EP4702293A1 true EP4702293A1 (en) 2026-03-04

Family

ID=98692845

Family Applications (1)

Application Number Title Priority Date Filing Date
EP24721922.3A Pending EP4702293A1 (en) 2023-04-24 2024-04-22 Process and apparatus for air separation by cryogenic distillation

Country Status (1)

Country Link
EP (1) EP4702293A1 (en)

Similar Documents

Publication Publication Date Title
US5379598A (en) Cryogenic rectification process and apparatus for vaporizing a pumped liquid product
EP1429099A1 (en) Process and apparatus for the recovery of krypton and/or xenon
US5735142A (en) Process and installation for producing high pressure oxygen
JP2002327981A (en) Cryogenic air-separation method of three-tower type
JPS581350B2 (en) Gaseous oxygen production method and low temperature plant for implementing the production method
US20110214453A1 (en) Process and device for cryogenic air fractionation
KR20030036029A (en) Process and apparatus for producing krypton and/or xenon by low-temperature fractionation of air
EP0384688B2 (en) Air separation
JPH11351738A (en) Method and system for producing high purity oxygen
EP2634517B1 (en) Process and apparatus for the separation of air by cryogenic distillation
US20090120128A1 (en) Low Temperature Air Fractionation with External Fluid
EP1999422B1 (en) Cryogenic air separation system
US8191386B2 (en) Distillation method and apparatus
JP2009509120A (en) Method and apparatus for separating air by cryogenic distillation.
JP7355980B1 (en) Ultra-high purity oxygen production method and ultra-high purity oxygen production equipment
JP2001349669A (en) Method and apparatus for manufacturing oxygen-rich fluid by low temperature distillation
US20130047666A1 (en) Method and device for obtaining pressurized nitrogen and pressurized oxygen by low-temperature separation of air
JPH11325717A (en) Separation of air
JP2000346547A (en) Cryogenic distillation for separating air
US20130086941A1 (en) Air separation method and apparatus
US20060075779A1 (en) Process for the cryogenic distillation of air
JPH04227460A (en) Low-temperature nitrogen generator with bottom reboiler and nitrogen expander
EP1030148B1 (en) Air separation
WO2024223491A1 (en) Process and apparatus for air separation by cryogenic distillation
EP4702293A1 (en) Process and apparatus for air separation by cryogenic distillation

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20251124

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR