EP1880155A2 - Procede d'epuration de flux gazeux - Google Patents

Procede d'epuration de flux gazeux

Info

Publication number
EP1880155A2
EP1880155A2 EP06750633A EP06750633A EP1880155A2 EP 1880155 A2 EP1880155 A2 EP 1880155A2 EP 06750633 A EP06750633 A EP 06750633A EP 06750633 A EP06750633 A EP 06750633A EP 1880155 A2 EP1880155 A2 EP 1880155A2
Authority
EP
European Patent Office
Prior art keywords
oxygen
stream
gas stream
crude
percent
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.)
Withdrawn
Application number
EP06750633A
Other languages
German (de)
English (en)
Other versions
EP1880155A4 (fr
Inventor
Jonathan Andrew Lane
Dante P. Bonaquist
Eric Shreiber
Bayram Arman
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 EP1880155A2 publication Critical patent/EP1880155A2/fr
Publication of EP1880155A4 publication Critical patent/EP1880155A4/fr
Withdrawn legal-status Critical Current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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/32—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by electrical effects other than those provided for in group B01D61/00
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
    • B01D53/225—Multiple stage diffusion
    • B01D53/226—Multiple stage diffusion in serial connexion
    • 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
    • F25J3/04733—Producing pure argon, e.g. recovered from a crude argon column using a hybrid system, e.g. using adsorption, permeation or catalytic reaction
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2256/00—Main component in the product gas stream after treatment
    • B01D2256/10—Nitrogen
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2256/00—Main component in the product gas stream after treatment
    • B01D2256/18—Noble gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/10—Single element gases other than halogens
    • B01D2257/104—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
    • F25J2205/00—Processes or apparatus using other separation and/or other processing means
    • F25J2205/80—Processes or apparatus using other separation and/or other processing means using membrane, i.e. including a permeation step
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2230/00—Processes or apparatus involving steps for increasing the pressure of gaseous process streams
    • F25J2230/58—Processes or apparatus involving steps for increasing the pressure of gaseous process streams the fluid being argon or crude argon

Definitions

  • the present invention relates to a method of purifying a gas stream in which the gas stream is introduced into a series of electrically driven oxygen separation zones having one or more oxygen ion conducting electrolytes to separate oxygen from the gas stream. More particularly, the present invention relates to such a purification method in which voltages are applied to each of the separation zones to induce an oxygen ion current that approaches a limiting value beyond which a further increase in voltage will not produce an increase in oxygen separation.
  • Electroly driven oxygen transport membranes are utilized to purify feeds by separating oxygen.
  • Such membranes employ an electrolyte which is normally an ionic conductor such as gadolinium doped ceria or yttrium stabilized zirconia. If the electrolyte is subjected to an elevated temperature and an electric potential is applied to electrodes sandwiching the electrolyte, oxygen will ionize at an electrode that serves as a cathode to produce oxygen ions. The oxygen ions will permeate through the membrane and emerge at the anode electrode . The oxygen ions combine to form elemental dioxygen and in so doing, give up excess electrons to the anode electrode.
  • US 5,454,923 illustrates a further inert gas purification system utilizing an electrochemical cell having a non porous electrolyte membrane coated with electrodes and heated to high temperatures.
  • the electrical power usage of any electrically driven oxygen transport membrane device is important in determining whether such operations will be economically feasible for purification purposes. This problem is particularly critical in purifying crude argon because a major expense in the cryogenic rectification of air arises from electrical power consumed, principally in the compression of the air. Therefore, the power consumption of an electrically driven oxygen separator and its use in purifying crude argon is critical to the profitability of an air separation plant making argon.
  • the same problem pertains to other gas purification systems, for example, purification of crude nitrogen streams produced by a pressure swing adsorption unit utilizing an adsorbent bed or a membrane system employing a polymeric membrane. Both types of units also consume electricity in compressing air and hence, power consumption is an important factor in the utilization of an electrically driven oxygen separator used for purifying crude nitrogen streams obtained from such sources.
  • the present invention provides a purification method that minimizes the use of electrical power for a specific size of an electrically driven oxygen separator.
  • the present invention provides a method of purifying a gas stream by removing oxygen from the gas stream.
  • the gas stream is introduced into a series of electrically driven oxygen separation zones that operate at an elevated temperature to separate the oxygen from the gas stream.
  • the separation of oxygen produces a purified gas stream.
  • Each of the electrically driven separation zones has an electrolyte and cathode and anode assemblies for applying a voltage to the electrolyte such that the oxygen ions are transported through the electrolyte and emerge therefrom to recombine into elemental oxygen. This separates the oxygen from the gas stream to produce the purified gas stream.
  • the oxygen is separated from the gas stream at a successively lower partial pressure due to the separation of the oxygen within the successive electrically driven oxygen separation zones.
  • Each of the electrically driven separation zones is capable of separating the oxygen as an increasing function of the voltage applied to the cathode and anode assemblies up to a level that induces an oxygen ion current that approaches a limiting oxygen ion current within the electrically driven oxygen separation zones.
  • a further increase in voltage fails to produce an increase in oxygen separation.
  • the limiting oxygen ion current is a function of the successively lower partial pressure such that the voltage applied decreases for each of the successive electrically driven oxygen separation zones.
  • the voltage is applied to each of the electrically driven oxygen separation zones in an amount selected such that the oxygen ion current approaches the limiting oxygen ion current applicable thereto.
  • constant voltage is applied to the electrically driven oxygen separation zone.
  • the gas stream traverses the device, it becomes evermore dilute in oxygen. As a result, the oxygen partial pressure decreases.
  • a voltage is not optimally being applied because as the gas to be treated passes through the membrane, the partial pressure of the gas decreases and the same voltage is not necessary.
  • Separately applying voltages so that the oxygen ion current approaches the limiting value in downstream zones of separation thereby reduces the overall power consumption of the membrane for a specific size of membrane required for a particular application.
  • the present invention has application to the purification of crude argon streams by removing oxygen from such streams.
  • the gas stream is a crude argon stream
  • the gas stream is formed by vaporizing a crude liquid argon stream withdrawn from a crude argon column of a cryogenic air separation plant and containing the oxygen in a range of between about 0.1 percent and about 3 percent by volume.
  • the crude liquid argon stream contains between 0.5 percent and about 2 percent by volume .
  • a further application of the present invention relates to the purification of gas streams that constitute crude nitrogen streams withdrawn from pressure swing adsorption units or membrane separation units.
  • the crude nitrogen stream can contain between about .05 percent and about 2 percent by volume oxygen. More preferably, the crude nitrogen stream contains between about .1 percent and about 1 - S -
  • the crude nitrogen stream contains between about .15 percent and about .5 percent by volume oxygen.
  • the oxygen ion current can be between about 80 percent and about 99.99 percent of the limiting oxygen ion current. In preferred modes of operation of the present invention, the oxygen ion current is at least about 95 percent of the limiting oxygen ion current .
  • the elevated operational temperature of the electrically driven oxygen separation zones is between about 600 0 C and about 900 0 C.
  • a temperature range of between about 650 0 C and about 800 0 C is more preferred and a range of between about 700 0 C and about 800 0 C is particularly preferred.
  • the electrolyte can be a common electrolyte extending through each of the electrically driven oxygen separation zones.
  • each of the electrically driven oxygen separation zones is defined between the particular cathode and anode assemblies at which the voltage is applied.
  • the electrically driven oxygen separation zones could be separate devices or separated from one another in the same device.
  • the initial zone could be formed from 8YSZ.
  • 8YSZ means yttria doped or stabilized zirconia containing about 8 percent by mole yttria.
  • the successive zones could be formed from 6YSZ or 3YSZ.
  • a crude liquid argon stream is vaporized through indirect heat exchange with an air stream, thereby to liquefy the air stream and thereby to form the crude argon gas stream to be purified.
  • the crude argon gas stream is heated through indirect heat exchange with the purified gas stream and the purified gas stream is liquefied through indirect heat exchange with a liquid air stream.
  • the crude liquid argon stream, the purified gas stream and a liquid nitrogen stream are subjected to indirect heat exchange, thereby to vaporize the crude liquid argon stream to form the crude argon stream to be purified, to vaporize the liquid nitrogen stream and to liquefy the purified gas stream.
  • the resultant crude argon gas stream is heated through further indirect heat exchange with the purified gas stream prior to the purified gas stream engaging in the heat exchange involving the purified gas stream and the crude liquid argon stream.
  • Further pressure is imparted to the crude argon stream by a blower to raise the pressure thereof above that of the purified gas stream to provide a better match of heating and cooling curves for the heat exchange between the liquid and gas streams.
  • the present invention provides vaporizing the crude liquid argon stream and liquefying the product stream in a main heat exchanger of a cryogenic air separation plant.
  • the crude argon stream can be heated through indirect heat exchange with the purified gas stream prior to liquefaction of the purified gas stream within the main _ ⁇ _
  • a compressed and purified air stream to be rectified in the cryogenic air separation plant can be cooled within the main heat exchanger and oxygen and nitrogen product streams of the cryogenic air separation plant can be warmed within the main heat exchanger .
  • the gas stream and the purified gas stream are subject to indirect heat exchange to heat the gas stream and cool the purified gas stream.
  • the pressure swing adsorption unit or the membrane separation unit can be operated at a lower capacity to produce the crude nitrogen stream at a higher purity than operations conducted at full capacity.
  • a trim heater can be employed to further heat the gas stream prior to treatment within the electrically driven oxygen separation zones.
  • the oxygen separated from the gas stream can be extracted with a purge stream.
  • the purge stream can be formed from part of the gas stream to be purified.
  • FIG. 1 is a schematic illustration of an oxygen separation device in accordance with the present invention
  • Fig. 2 is a graphical representation of applied voltage versus ionic current as a fraction of the limiting ionic current in an electrically driven oxygen separation device
  • FIG. 3 is a schematic illustration of the use of the oxygen separation device illustrated in Fig. 1 applied to the purification of crude argon;
  • Fig. 4 is an alternative embodiment of Fig. 3;
  • Fig. 5 is an alternative embodiment of Fig. 4 ;
  • FIG. 6 is a schematic illustration of the use of the oxygen separation device illustrated in Fig. 1 applied to the purification of crude nitrogen.
  • Fig. 6 is a schematic illustration of the use of the oxygen separation device illustrated in Fig. 1 applied to the purification of crude nitrogen.
  • an electrically- driven oxygen separation device 10 is illustrated that is designed to purify a gas stream 12 to produce a purified gas stream 14 through separation of oxygen from gas stream 12.
  • the oxygen is separated within electrically driven oxygen separation zones 16, 18 and 20 that are defined by three cathode and anode assemblies having cathode and anode electrodes 22, 24; 26, 28 and 30, 32, respectively.
  • the cathode and anode assemblies would also be provided with conventional current collectors.
  • Said electrodes and current collectors are all porous and sandwich an electrolyte 34, which as will be discussed may have separate sections.
  • cathode and anode assemblies and electrolyte 34 are housed within a casing 35 to define passageways 36 and 37 on opposite sides of electrolyte 34. It is to be noted as used herein and in the claims, the term "cathode and anode assemblies" means porous cathodes and anodes and associated porous current collectors.
  • Electrodes 22, 24; 26, 28; and 30, 32 are so named in that they consist of electrically conductive materials. Conventional current collectors form outer layers of the electrodes and are in turn connected to direct current electrical power sources 38, 39 and 40. As illustrated, different voltages are applied to cathode electrodes and anode electrodes 22, 24; 26, 28; and 30, 32 by electrical power sources 38, 39 and 40 such that the oxygen within gas stream 12 passing through passageway 36 ionizes at the juncture of pores within cathodes 22, 26 and 30 and the electrolyte 34 and the resultant oxygen ions are transported through the electrolyte 34 to anode electrodes 24, 28 and 32.
  • the oxygen ions combine at the juncture of pores within anode electrodes 24, 28 and 32 and electrolyte 34 to form elemental dioxygen.
  • the resultant free electrons are conducted within anodes 24, 28 and 32 back to electrical power sources 38, 39 and 40.
  • the oxygen is extracted by way of a purge gas stream 42 introduced into passageway 37 to sweep and remove the oxygen from electrically driven oxygen separation device 10.
  • Purge gas stream 42 can be nitrogen or other inert gas containing less than about 21 percent oxygen. Other known extraction means can be employed such as vacuum extraction.
  • Purge gas stream 42 is discharged as oxygen containing purge gas stream 44.
  • the electrolyte 34 is of tubular configuration, about 0.5 mm thick, about 6.3 mm in outside diameter and has an overall length of about 91 cm to provide a surface area of about 160 cm 2 .
  • the cathodes 22, 26 and 30 are fabricated from a mixture of 50wt% lanthanum strontium manganite (La 0 . 8 Sr 0 . 2 MnO 3 + ⁇ ) and 50wt% yttria-stabilized zirconia (Zro.85Yo.15O1.g25) . Each are between about 10 and about 30 microns thick, have an average pore size of 10 microns and a porosity of about 40 percent.
  • the current collector can be silver and have a thickness of between about 50 and about 100 microns, a pore size of about 10 microns and a porosity of about 40 percent.
  • the anodes 24, 28 and 32 are fabricated from a mixture of 50wt% lanthanum strontium manganite (La 0 . 8 Sr 0 .2MnO 3 ⁇ ⁇ ) and 50 wt% yttria-stabilized zirconia (Zro.s5Yo.15O1. 9 2 5 ) • Each of the anodes are about 20 micron thick, have pores with a pore size of about 5 micron and a porosity of about 40 percent.
  • the assemblies of cathode and anode electrode 22, 24; 26, 28 and 30, 32 divide the electrolyte into three equal portions 46, 48 and 50 with gaps 52 and 54 of about 1 cm between each of the same.
  • the gaps are spacers that can be fabricated of YSZ and connected to portions 46, 48 and 50 by glass sealing, brazing or other bonding and sealing technique.
  • casing 35 could thus be fabricated from three separate sections with flow connection between said sections for the passage of gas stream 12 and purge gas stream 42 on opposite sides of the electrolyte.
  • electrolyte 34 is shown as broken up into three portions 46, 48 and 50, 46, in a possible embodiment of the present invention, electrolyte 34 could be common to all electrically driven oxygen separation zones 16, 18 and 20 with no gaps.
  • the actual voltage that is applied across the electrolyte 34 has to be greater than the Nernst potential due to a difference in the oxygen partial pressure on the anode and cathode side in order for oxygen to be removed from gas stream 10.
  • the Nernst potential is described by the following equation:
  • the upper limit of the voltage that can be possibly applied is a voltage that will cause failure of electrolyte 34 due to electrochemical reduction. Electrochemical reduction can induce electronic conductivity into electrolyte 34 rendering it electrically inefficient for oxygen ion conduction. Additionally, such reduction can also cause isothermal expansion which will generate stresses in electrolyte 34 that can be sufficient to cause it to fracture. Typically, the maximum voltage is 2 volts. However, as will be discussed, the voltage that should be applied in each of the electrically driven oxygen separation zones 16, 18 and 20 and portions 46, 48 and 50 of electrolyte 34 should be much less than the ultimate limit .
  • a graphical representation is illustrated of applied voltage versus ionic current as a fraction of a limiting ionic current that is induced within electrolyte 34.
  • the ionic current is a measure of the ionic flux passing through electrolyte 34 per unit area and is analogous of the flux of electrons passing through a conductor to measure an electrical current.
  • the behavior of applied voltage illustrated in Fig. 2 is governed by the following equation:
  • R is the gas constant
  • T is the temperature in Kelvin
  • F is the Faraday constant
  • I is current
  • the voltage to be applied should decrease. For example, in case of an argon stream containing 2 percent oxygen, a voltage of 2 volts can be applied without reaching a limiting current. However, as oxygen is removed from the argon stream down to 100 parts per million, then a limiting current can be observed when a voltage of approximately 0.6 volts is applied.
  • the particular value of the limiting current and the applied voltage that results in the limiting current is a complicated function of the temperature, the oxygen partial pressure on either side of the electrolyte, the composition of the atmosphere on either side of the electrolyte, the electrochemical performance, the size of the electrolyte, the microstructure of electrodes on either side of the electrolyte and the particular electrochemical mechanism that is giving rise to the limiting current behavior .
  • the applied voltage can be chosen as to result in an oxygen ion current that is between about 80 percent and about 99.9 percent of the oxygen ion limiting current. In any embodiment it is preferred, however, that the oxygen ion current induced in an electrolyte is at least about 95 percent of the oxygen ion limiting current.
  • power source 38 applies 1.5 volts between cathode electrode 22 and anode electrode assembly 24 within zone 16. Assuming that an argon stream or a crude nitrogen stream is to be purified that contains roughly 1.8 percent oxygen, a significant amount of the oxygen will be removed within zone 16 so that the stream exiting 16 and entering 18 should contain approximately 1000 parts per million oxygen. Power source 39 supplies about 1 volt between cathode and anode electrodes 26 and 28 within zone 18 and the stream exiting zone 18 should contain roughly 100 parts per million oxygen. Power source 40 applies 0.5 volts between cathode and anode electrodes 30 and 32 so that purified gas stream 14 has an oxygen concentration of about 10 parts per million. As can be appreciated, had 1.5 volts been applied throughout electrochemical device 10 much more power would have been consumed.
  • the total electrochemical performance of electrolyte 34 is governed by the performance of electrolyte 34 and assemblies of the cathodes and anodes.
  • the electrolyte 34 should have a high oxygen ion conductivity. 8 mole percent yttria doped zirconia (8YSZ, Zro.852Yo.i48 ⁇ i.92 ⁇ ) is preferred.
  • Other electrolyte material such as gadolinium doped ceria and lanthanum strontium gadolinium magnesium oxide are possible materials because they possess even higher ionic conductivity than 8YSZ. However the increased cost and lower strength of these materials outweigh their improved electrochemical performance in a practical device .
  • the resistance of the electrolyte is a function of the oxygen partial pressure and the resistance in the cathode is proportional to the oxygen partial pressure according to the following equation:
  • cathode ⁇ PC* 2 where n is an experimentally determined number between 1 and 4, inclusive.
  • n is an experimentally determined number between 1 and 4, inclusive.
  • an electrolyte material with a lower ionic conductivity but improved strength such as 6 mole percent yttria doped zirconia (6YSZ, or 3 mole percent yttria doped zirconia (3YSZ, Zr 0 . 942 Yo.o 58 ⁇ i. 97 i) .
  • portion 46 of electrolyte 34 can be fabricated from 8 mole percent yttria doped zirconia ("8YSZ") and portions 48 and 50 can be fabricated from either 6 or 3 mole percent yttria doped zirconia.
  • 8YSZ 8 mole percent yttria doped zirconia
  • portions 48 and 50 can be fabricated from either 6 or 3 mole percent yttria doped zirconia.
  • the membrane will operate somewhere between 600 0 C and about 900 0 C, more preferably between about 650 0 C and about 850 0 C and most preferably between 700 0 C and about 800 0 C.
  • electrically driven oxygen separation device 10 is shown as an oxygen purifier to purify a crude liquid argon stream 60 obtained from an air separation unit.
  • an air stream is compressed, purified and cooled to at or near its dew point.
  • the cooled air stream is introduced into the bottom of a higher pressure column to produce a crude oxygen column bottoms and a nitrogen rich overhead.
  • the resulting tower overhead is condensed and further refined in a lower pressure column that produces an oxygen rich column bottoms and a nitrogen rich tower overhead.
  • the oxygen rich liquid column bottoms serves to condense the tower overhead produced in the higher pressure column and the crude liquid oxygen produced in the higher pressure column is expanded and used to condense tower overhead in the lower pressure column.
  • a vapor stream having an argon concentration within the range of between about 5 and about 25 percent is withdrawn from the lower pressure column and introduced into the bottom of a crude argon column.
  • the crude argon column operates as a stripping column so that the argon content of the vapor increases as the vapor rises within the column and contacts a descending liquid phase. The liquid phase thereby becomes evermore enriched in oxygen during its descent within the column.
  • a product stream can be withdrawn from the top of the argon column as a liquid to form the crude liquid argon stream 60. The liquid column bottoms is returned to the lower pressure column.
  • Crude liquid argon stream 60 preferably has an oxygen concentration of between about 0.1 percent and about 3 percent by volume. More preferably, crude liquid argon stream 60 has an oxygen concentration of between about 0.5 percent and about 2 percent by volume. The reason for such ranges is that typically crude liquid argon has an oxygen concentration of about 3 percent by volume and with limited added expense, the oxygen concentration in the crude liquid argon stream can be reduced by a slight increase in the number of stages. The reduced oxygen content reduces the amount of power required for electrically driven oxygen separation device 10.
  • Crude liquid argon stream 60 is vaporized within a heat exchanger 62 through indirect heat exchange with an air stream 64 that is thereby liquefied.
  • the resultant gaseous crude argon stream 66 is introduced into a heat exchanger 68 to form gas stream 12 that is introduced into electrically driven oxygen separation device 10 to produce purified gas stream 14.
  • Purified gas stream 14 exchanges heat with gaseous crude argon stream 66 within heat exchanger 68 so that gas stream 12 to be purified possess a temperature at or near the operational temperature of electrically driven oxygen separation device 10.
  • Purified gas stream 14 after passage through heat exchanger 68 is cooled to ambient or near ambient temperatures as a result of such heat exchange.
  • Purified gas stream 14 is then introduced into a heat exchanger 70 in which the purified gas stream 14 liquefies through indirect heat exchange with a liquid air stream 72 that can be extracted from the higher pressure distillation column.
  • a trim heater 74 can be provided so that gas stream 12 upon its introduction into electrically driven oxygen separation device 10 is exactly at operational temperature.
  • a purge gas stream 42 is introduced into electrically driven oxygen separation device 10 to extract the separated oxygen.
  • Fig. 4 is an alternative embodiment of Fig. 3.
  • crude liquid argon stream 60 vaporizes along with a liquid nitrogen stream 76 within a heat exchanger 78 to in turn liquefy purified gas stream 14.
  • Purified gas stream 14 is at a lower pressure than that of crude liquid argon stream 60 and therefore, a thermal mismatch exists that would not permit purified gas stream 14 to otherwise vaporize crude liquid argon stream 60.
  • crude liquid argon stream 60 and purified gas stream 14 are introduced into a main heat exchanger 82 of a cryogenic air separation plant.
  • main heat exchanger 82 crude liquid argon stream 60 vaporizes and product stream 14 after having been cooled in heat exchanger 68 liquefies.
  • Main heat exchanger 82 is conventionally provided with passages for nitrogen and oxygen product streams 84 and 86 to warm such streams.
  • nitrogen product stream 84 could be made up of tower overhead produced in a lower pressure column of such cryogenic air separation plant and oxygen product stream 86 could be liquid oxygen or oxygen vapor made up of oxygen produced as column bottoms within the lower pressure column.
  • a further passage is also provided for a compressed and purified air stream 88 that is cooled within main heat exchanger 82 to a temperature at or near its dew point for introduction into the bottom region of a higher pressure column for rectification of the air.
  • the flow rates of crude liquid argon stream 60 and product gas stream 14 are of such lesser magnitudes than the other streams passing through main heat exchanger 82, that the foregoing can be effectuated by a retrofit modification of an existing main heat exchanger without any significant effect on its performance.
  • a blower 80 can be provided to provide a better match between heating and cooling curves of product gas stream 14 and crude liquid argon stream 60.
  • the illustrated gas streams are sufficiently pressurized to flow through the heat exchangers by provision of a liquid head being built up within crude liquid argon stream 60 by locating the argon column from which crude liquid argon stream 60 is taken above grade .
  • electrically driven oxygen separation device 10 is shown as an oxygen purifier to purify a crude nitrogen stream 90 obtained from a pressure swing adsorption unit or a membrane unit.
  • a pressure swing adsorption unit has beds of adsorbent that can be formed of carbon molecular sieve material. The air is compressed and passed through an adsorbing bed to adsorb oxygen contained in the air to produce the crude nitrogen stream 82. While this is occurring at least another bed is off-line and being regenerated by allowing oxygen to desorb from the adsorbent contained in such bed at a lower pressure .
  • Part of the regeneration can occur by pressure equalization with yet other beds and various purge steps that can involve purging the bed to be regenerated with some of the product. After the bed is fully regenerated, it can be brought back on line to produce a product.
  • membrane separation units a compressed air stream is contacted with a polymeric membrane that is made of material selected to pass oxygen faster than nitrogen to produce a permeate stream rich ' in oxygen and a nitrogen retentate stream that forms the crude nitrogen stream 82.
  • Crude nitrogen stream 90 is heated within a heat exchanger 92 through indirect heat exchange with product gas stream 14 to form gas stream 12 that is introduced into electrically driven oxygen separation device 10 to produce purified gas stream 14.
  • Gas stream 12 as a result of such heat exchange possesses a temperature near the operational temperature of electrically driven oxygen separation device 10.
  • a trim heater 94 can be used for final heating of gas stream 12 to the operational temperature of electrically driven oxygen separation device 10.
  • Purified gas stream 14 after passage through heat exchanger 92 is cooled to ambient or near ambient temperatures as a result of such heat exchange . Additionally part of the gas stream 12 can be used to form purge stream 42 to sweep and remove permeated oxygen from electrically driven oxygen separation device 10.
  • crude nitrogen stream preferably contains about 0.5 volume percent of oxygen and is heated to about 700°C within heat exchanger 92.
  • the electrically driven oxygen separation device 10 operated at about 700 0 C requiring a temperature rise of 50°C to account for atmospheric heat loss or roughly 113 watts per 100 scfh of crude nitrogen. Since, the electrically driven oxygen separation device 10 requires roughly 93 watts per 100 scfh of crude nitrogen under such operational conditions, about 20 watts per 100 scfh of crude nitrogen is required for trim heater 94 to maintain stable operating temperatures.
  • Crude nitrogen stream 90 preferably has an oxygen concentration of between about .05 percent and about 2 percent by volume oxygen. More preferably, the oxygen concentration is between about .1 percent and about 1 percent by volume oxygen. Most preferably, the oxygen concentration is between about .15 percent and about .5 percent by volume oxygen. It has been calculated, that a minimum power usage for electrically driven oxygen separation device 10 is achieved when crude nitrogen stream contains about 1.5 percent by volume oxygen. A minimum capital cost for the entire system, including a pressure swing adsorption unit, is realized when the crude nitrogen stream contains about 0.15 percent by volume oxygen. Overall, when the crude nitrogen stream contains between about 0.15 percent and about .5 percent oxygen by volume, the lowest total cost will be achieved for a 10,000 scfh system.
  • the pressure swing adsorption unit or membrane separation unit should be operated at a lower capacity and therefore produce a crude nitrogen stream 90 at a lower flow rate and therefore at a higher purity. This allows the customer to receive the product while the electrically driven oxygen separation device 10 is being heated up. For most pressure swing adsorption units, during start-up, such units should be operated at about 30 percent of capacity to produce crude nitrogen stream 90 with an oxygen concentration of about 50 ppm. Also, the pressure swing adsorption unit or membrane separation unit can be operated in such manner during maintenance of any of the electrically- driven oxygen separation zones 16, 18 and 20. [0055] While the present invention has been described with reference to a preferred embodiment, as will occur to those skilled in the art numerous changes, omissions and additions can be made without departing from the spirit and the scope of the present invention.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)
  • Oxygen, Ozone, And Oxides In General (AREA)
  • Separation By Low-Temperature Treatments (AREA)
  • Separation Of Gases By Adsorption (AREA)

Abstract

L'invention concerne un procédé permettant d'épurer un flux gazeux (12) en prélevant du flux gazeux de l'oxygène dans lequel ledit flux gazeux (12) est introduit en séries de zones de séparation d'oxygène entraîné électriquement (16, 18, 20) qui séparent l'oxygène du flux gazeux (12). Chacune de ces zones (16, 18, 20) a un électrolyte (34) qui conduit l'oxygène lors de l'application de la tension (38, 39, 40) à des électrodes (22,24; 26, 28; 30, 32) prenant en sandwich l'électrolyte (34). La tension (38, 39, 40) appliquée à chacune des électrodes (22,24; 26, 28; 30, 32) des zones séparées (16, 18, 20) est choisie de façon qu'un courant ionique induit dans l'électrolyte (34) dans une zone particulière (16, 18, 20) n'excède pas un courant de limitation. Lorsque la tension (38, 39, 40) est ainsi appliquée, la puissance électrique consommée est réduite par rapport à la puissance qui aurait été consommée si l'on avait appliqué une tension constante à toutes les zones (16, 18, 20). Le flux gazeux (12) peut être un flux d'argon brut (60) obtenu à partir d'une colonne d'argon brut ou un flux d'azote brut (90) obtenu à partir d'une unité d'adsorption à oscillation en pression ou d'une unité membranaire polymère.
EP06750633A 2005-04-22 2006-04-19 Procede d'epuration de flux gazeux Withdrawn EP1880155A4 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/111,837 US20060236719A1 (en) 2005-04-22 2005-04-22 Gas stream purification method utilizing electrically driven oxygen ion transport
PCT/US2006/014639 WO2006115916A2 (fr) 2005-04-22 2006-04-19 Procede d'epuration de flux gazeux

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EP1880155A2 true EP1880155A2 (fr) 2008-01-23
EP1880155A4 EP1880155A4 (fr) 2010-11-17

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US (1) US20060236719A1 (fr)
EP (1) EP1880155A4 (fr)
JP (1) JP5094708B2 (fr)
KR (1) KR20080010428A (fr)
CN (1) CN101495678A (fr)
BR (1) BRPI0610021A2 (fr)
CA (1) CA2606332C (fr)
MX (1) MX2007013116A (fr)
WO (1) WO2006115916A2 (fr)

Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090139497A1 (en) * 2007-11-30 2009-06-04 Bo Shi Engine having thin film oxygen separation system
US8465630B2 (en) * 2008-11-10 2013-06-18 Praxair Technology, Inc. Oxygen separation assembly and method
JP5634832B2 (ja) * 2010-11-15 2014-12-03 キヤノンマシナリー株式会社 酸素分圧制御方法
US9561476B2 (en) 2010-12-15 2017-02-07 Praxair Technology, Inc. Catalyst containing oxygen transport membrane
US8409323B2 (en) 2011-04-07 2013-04-02 Praxair Technology, Inc. Control method and apparatus
EP2791082B1 (fr) 2011-12-15 2021-01-20 Praxair Technology, Inc. Procédé de préparation d'une membrane composite de transport d'oxygène
US9486735B2 (en) 2011-12-15 2016-11-08 Praxair Technology, Inc. Composite oxygen transport membrane
US9969645B2 (en) 2012-12-19 2018-05-15 Praxair Technology, Inc. Method for sealing an oxygen transport membrane assembly
US9453644B2 (en) 2012-12-28 2016-09-27 Praxair Technology, Inc. Oxygen transport membrane based advanced power cycle with low pressure synthesis gas slip stream
US9212113B2 (en) 2013-04-26 2015-12-15 Praxair Technology, Inc. Method and system for producing a synthesis gas using an oxygen transport membrane based reforming system with secondary reforming and auxiliary heat source
US9938145B2 (en) 2013-04-26 2018-04-10 Praxair Technology, Inc. Method and system for adjusting synthesis gas module in an oxygen transport membrane based reforming system
US9611144B2 (en) 2013-04-26 2017-04-04 Praxair Technology, Inc. Method and system for producing a synthesis gas in an oxygen transport membrane based reforming system that is free of metal dusting corrosion
US9296671B2 (en) 2013-04-26 2016-03-29 Praxair Technology, Inc. Method and system for producing methanol using an integrated oxygen transport membrane based reforming system
WO2015054228A2 (fr) 2013-10-07 2015-04-16 Praxair Technology, Inc. Réacteur à réseau de membranes de transport d'oxygène céramiques et procédé de reformage
RU2661581C2 (ru) 2013-10-08 2018-07-17 Праксайр Текнолоджи, Инк. Система и способ регулирования температуры в реакторе на основе кислородпроводящих мембран
WO2015084729A1 (fr) 2013-12-02 2015-06-11 Praxair Technology, Inc. Procédé et système de production d'hydrogène au moyen d'un système de reformage à base de membrane de transport d'oxygène avec un reformage secondaire
US9562472B2 (en) 2014-02-12 2017-02-07 Praxair Technology, Inc. Oxygen transport membrane reactor based method and system for generating electric power
US10822234B2 (en) 2014-04-16 2020-11-03 Praxair Technology, Inc. Method and system for oxygen transport membrane enhanced integrated gasifier combined cycle (IGCC)
US9789445B2 (en) 2014-10-07 2017-10-17 Praxair Technology, Inc. Composite oxygen ion transport membrane
US10441922B2 (en) 2015-06-29 2019-10-15 Praxair Technology, Inc. Dual function composite oxygen transport membrane
US10118823B2 (en) 2015-12-15 2018-11-06 Praxair Technology, Inc. Method of thermally-stabilizing an oxygen transport membrane-based reforming system
US9938146B2 (en) 2015-12-28 2018-04-10 Praxair Technology, Inc. High aspect ratio catalytic reactor and catalyst inserts therefor
JP2019513081A (ja) 2016-04-01 2019-05-23 プラクスエア・テクノロジー・インコーポレイテッド 触媒含有酸素輸送膜
FR3074059B1 (fr) * 2017-11-24 2022-04-15 Univ Grenoble Alpes Procede de purification d'un gaz porteur
US11136238B2 (en) 2018-05-21 2021-10-05 Praxair Technology, Inc. OTM syngas panel with gas heated reformer

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0887099A2 (fr) * 1997-06-23 1998-12-30 Praxair Technology, Inc. Procédé pour la séparation d'oxygène d'un mélange de gaz utilisant une membrane à électrolyte solide
US6290757B1 (en) * 1999-03-26 2001-09-18 Ceramphysics, Inc. Nitrogen purification device
US20020134236A1 (en) * 2000-10-10 2002-09-26 Jensvold John A. Ceramic deoxygenation hybrid systems for the production of oxygen and nitrogen gases

Family Cites Families (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5035726A (en) * 1990-05-24 1991-07-30 Air Products And Chemicals, Inc. Process for removing oxygen from crude argon
US5454923A (en) * 1991-06-04 1995-10-03 Ceramatec, Inc. Inert gas purifying system
US5226931A (en) * 1991-10-24 1993-07-13 Canadian Liquid Air Ltd. -Air Liquide Canada Ltee. Process for supplying nitrogen from an on-site plant
JP3100797B2 (ja) * 1993-05-20 2000-10-23 キヤノン株式会社 電源装置
DE4333230B4 (de) * 1993-09-30 2004-03-25 Robert Bosch Gmbh Elektrochemischer Meßfühler zur Bestimmung des Sauerstoffgehalts in Gasen
JPH07105991A (ja) * 1993-10-04 1995-04-21 Matsushita Electric Ind Co Ltd 電池用酸素富化膜
US5547494A (en) * 1995-03-22 1996-08-20 Praxair Technology, Inc. Staged electrolyte membrane
US5557951A (en) * 1995-03-24 1996-09-24 Praxair Technology, Inc. Process and apparatus for recovery and purification of argon from a cryogenic air separation unit
KR0148713B1 (ko) * 1995-12-22 1998-08-17 김은영 다공성세라믹 확산장벽 조성물
JP3107747B2 (ja) * 1996-06-13 2000-11-13 株式会社ノリタケカンパニーリミテド 限界電流式酸素センサ用流量制限体およびその製造方法
GB9823651D0 (en) * 1998-10-29 1998-12-23 Normalair Garrett Ltd Gas generating system
JP2000155117A (ja) * 1998-11-18 2000-06-06 Shimadzu Corp 燃焼酸化方式元素分析計
US20020114747A1 (en) * 2000-12-28 2002-08-22 Kevin Marchand Fuel processing system and apparatus therefor
US6500235B2 (en) * 2000-12-29 2002-12-31 Praxair Technology, Inc. Pressure swing adsorption process for high recovery of high purity gas
US6692545B2 (en) * 2001-02-09 2004-02-17 General Motors Corporation Combined water gas shift reactor/carbon dioxide adsorber for use in a fuel cell system
US6623714B2 (en) * 2001-06-04 2003-09-23 Praxair Technology, Inc. Oxygen separation method using a ceramic membrane unit
US6565632B1 (en) * 2001-12-17 2003-05-20 Praxair Technology, Inc. Ion-transport membrane assembly incorporating internal support
US6764534B2 (en) * 2002-01-31 2004-07-20 Airsep Corporation Portable oxygen concentrator
JP2003320226A (ja) * 2002-04-26 2003-11-11 Toyota Motor Corp 水素透過膜および水素抽出装置
JP2004008859A (ja) * 2002-06-04 2004-01-15 Mitsubishi Electric Corp 湿度調整器の運転方法及び劣化部位推定方法
US6838066B2 (en) * 2002-09-13 2005-01-04 Air Products And Chemicals, Inc. Process for recovery, purification, and recycle of argon
US7501009B2 (en) * 2006-03-10 2009-03-10 Air Products And Chemicals, Inc. Combined cryogenic distillation and PSA for argon production
US7556676B2 (en) * 2006-08-22 2009-07-07 Praxair Technology, Inc. Composite oxygen ion transport membrane

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0887099A2 (fr) * 1997-06-23 1998-12-30 Praxair Technology, Inc. Procédé pour la séparation d'oxygène d'un mélange de gaz utilisant une membrane à électrolyte solide
US6290757B1 (en) * 1999-03-26 2001-09-18 Ceramphysics, Inc. Nitrogen purification device
US20020134236A1 (en) * 2000-10-10 2002-09-26 Jensvold John A. Ceramic deoxygenation hybrid systems for the production of oxygen and nitrogen gases

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
A. Q. PHAM, R. S. GLASS: "Oxygen pumping characteristics of yttria-stabilized-zirconia" ELECTROCHIMICA ACTA, vol. 43, no. 18, 16 June 1998 (1998-06-16), pages 2699-2708, XP002600643 *
E.C. SUBBARAO, H.S. MAITI: "SOLID ELECTROLYTES WITH OXYGEN ION CONDUCTION" SOLID STATE IONICS, vol. 11, no. 04, 31 January 1984 (1984-01-31), pages 317-338, XP002600644 *
See also references of WO2006115916A2 *

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MX2007013116A (es) 2008-01-14
CN101495678A (zh) 2009-07-29
WO2006115916A3 (fr) 2009-04-16
EP1880155A4 (fr) 2010-11-17
WO2006115916A2 (fr) 2006-11-02
JP2008538533A (ja) 2008-10-30
BRPI0610021A2 (pt) 2011-10-11
JP5094708B2 (ja) 2012-12-12
CA2606332A1 (fr) 2006-11-02
CA2606332C (fr) 2013-02-12
KR20080010428A (ko) 2008-01-30
US20060236719A1 (en) 2006-10-26

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