Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B21/00—Nitrogen; Compounds thereof
  • C01B21/04—Purification or separation of nitrogen
  • C01B21/0405—Purification or separation processes
  • C01B21/0411—Chemical processing only
  • C01B21/0416—Chemical processing only by oxidation
• • 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
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
  • B01D53/86—Catalytic processes
  • B01D53/864—Removing carbon monoxide or hydrocarbons
• • 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
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
  • B01D53/86—Catalytic processes
  • B01D53/8671—Removing components of defined structure not provided for in B01D53/8603 - B01D53/8668
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
  • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
  • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
  • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
  • F25J3/04163—Hot end purification of the feed air
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
  • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
  • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
  • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
  • F25J3/04163—Hot end purification of the feed air
  • F25J3/04169—Hot end purification of the feed air by adsorption of the impurities
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B2210/00—Purification or separation of specific gases
  • C01B2210/0043—Impurity removed
  • C01B2210/005—Carbon monoxide
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B2210/00—Purification or separation of specific gases
  • C01B2210/0043—Impurity removed
  • C01B2210/0053—Hydrogen
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2205/00—Processes or apparatus using other separation and/or other processing means
  • F25J2205/82—Processes or apparatus using other separation and/or other processing means using a reactor with combustion or catalytic reaction
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2215/00—Processes characterised by the type or other details of the product stream
  • F25J2215/42—Nitrogen or special cases, e.g. multiple or low purity N2
  • F25J2215/44—Ultra high purity nitrogen, i.e. generally less than 1 ppb impurities
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/151—Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Definitions

• the present invention relates to a simplified process for purifying air into its carbon monoxide and / or hydrogen impurities, in particular with a view to the production of high-purity nitrogen by cryogenic distillation of the purified air.
• the processes for the preparation of pure or very pure nitrogen firstly implement a step of separating nitrogen from the air, in particular by cryogenic distillation, the nitrogen obtained then being purified into its impurities , in particular carbon monoxide and / or hydrogen.
• Oxygen is reacted with carbon monoxide and hydrogen present in the nitrogen, using a catalyst containing reduced copper, at a temperature between 150 ⁇ C and 250 ° C to form carbon dioxide and water,
• the carbon monoxide and the residual hydrogen are reacted with the oxygen of a catalyst containing copper oxide, at a temperature between 150 ° C and 250 ° C, to form carbon dioxide, water and reduced copper,
• the air to be distilled is removed from the water and carbon dioxide, by adsorption, for example, on a molecular sieve, and the nitrogen is separated from the air by cryogenic distillation.
• the nitrogen thus obtained has carbon monoxide and hydrogen contents which may be less than 10 ppb.
• the latter method has the advantage of removing carbon monoxide and / or hydrogen impurities directly from the air which is subsequently cryogenic distilled.
• a purification carried out on nitrogen requires the addition of oxygen in an amount sufficient to oxidize carbon monoxide and hydrogen. However, this oxygen risks contaminating the nitrogen.
• a disadvantage of the process described in patent application EP 454,531 consists in having to use a desiccation-decarbonation of air in order to eliminate by adsorption the water and the carbon dioxide which it contains, not only after 1 'removal operation of carbon monoxide and / or hydrogen, but also, prior to this operation.
• This preliminary desiccation-decarbonation is very particularly required when the removal of carbon monoxide and / or hydrogen is carried out at temperatures below 120 ° C. and in particular at ambient temperature or at a temperature close thereto, either at a temperature between -20 e and 50 ⁇ C.
• the air leaving this compressor is brought to a temperature usually below 140 ° C, more generally between
• a first object of the invention consists in a process for purifying the air of its carbon monoxide and / or hydrogen impurities with a view to the preparation of ultra-pure nitrogen, the hydrogen and / or monoxide contents of which of carbon are less than 10 ppb, or even 5 ppb.
• a second object of the invention consists in a process for purifying the air of its carbon monoxide and / or hydrogen impurities which can be implemented by means of an installation of reduced cost, not requiring, prior to the 'elimination of these impurities, devices for desiccation-decarbonation by adsorption, heat exchange, cooling unit or air heating.
• a third object of the invention consists in a process for purifying the air of its carbon monoxide and / or hydrogen impurities, the energy cost of which is reduced, to the extent that on the one hand, it makes it possible to use the energy of the air leaving a compressor and on the other hand, avoids subsequently heating this air in a heater.
• a fourth object of the invention consists of a device for implementing a process for purifying the air of its carbon monoxide and / or hydrogen impurities.
• the invention then relates to a process for purifying air of its carbon monoxide and / or hydrogen impurities, in particular for the preparation of ultra-pure nitrogen, characterized in that: (i) the air is put in contact with a catalytic bed comprising particles of at least one metal chosen from copper, platinum, palladium, osmium, iridium, ruthenium, rhenium and rhodium, supported by a chemically inert support with respect to at least water, so as to react the carbon monoxide and / or hydrogen impurities with the oxygen in the air to form carbon dioxide and water respectively,
• a support which is chemically inert with respect to water is intended to mean a support which makes it possible to avoid rapid deactivation of the catalytic bed when it is brought into contact with 'water. Such a support is generally hydrophobic, and therefore does not substantially absorb water.
• a suitable support according to the process of the invention usually adsorbs less than 0.5 g of water per 100 g of support, preferably less than 0.2 g of water per 100 g of support, at 20 ° C. and with a relative humidity less than or equal to 60%.
• said support is also chemically inert vis-à-vis carbon dioxide.
• said support can in particular be chosen so as not to adsorb, substantially, the carbon dioxide.
• FIG. 1 represents a device for purifying air intended for distillation, comprising a catalytic bed disposed downstream of the air compressor.
• FIG. 2 represents a device for purifying air intended for distillation, comprising a catalytic bed arranged upstream of the air compressor.
• the process according to the invention is advantageously carried out so that bringing the air into contact with the catalytic bed produced before any air treatment aimed at drying and / or decarbonating this air by adsorption.
• the catalytic bed comprises only, or essentially, palladium particles.
• the support constituting the catalytic bed is preferably of mineral nature. It may in particular consist of a hydrophobic mineral, such as a hydrophobic zeolite, a hydrophobic silica, an amorphous alumina such as alumina, or a ceramic.
• An amorphous alumina can be obtained by calcination of a crystalline alumina, preferably under an inert atmosphere, at a temperature between 560 "C and 950 ° C, more generally between 750 ⁇ C and 850 ° C.
• a suitable hydrophobic zeolite can consist in particular of a zeolite ZSM 5, a silicalite or a zeolite Y highly dealuminated, and therefore, whose Si / Ai ratio is high. This ratio can be greater than 50, and preferably it is close to 100.
• hydrophobic zeolites which can be used in the process of the invention, mention may also be made of zeolites, such as the treated ordenites, of conventionally, with steam and then with an acid such as nitric acid, so as to remove the hydroxyl groups.
• the support constituting the catalytic bed has a volume of pores
• the radius of the pores of this support is preferably less than or equal to 25 nm, more preferably between 1 and 15 nm.
• the support used can be in various forms, for example in the form of shavings or honeycomb (monolith structure), but preferably it is in the form of balls or grains, which can be placed in a reactor.
• the content of metal particles in the catalytic bed is advantageously between 0.1 and 1% by weight, preferably between 0.4 and 0.7% by weight relative to the total weight of said catalytic bed.
• the catalytic bed used according to the process of the invention can be prepared according to means known in themselves, for example by the ion exchange technique or, preferably by the impregnation technique.
• the catalytic bed can be prepared by impregnating the support with an aqueous solution of a copper, platinum, palladium, osmium, iridium, ruthenium, rhenium and / or rhodium salt.
• the impregnated support is dried, for example by placing it for 12 to 48 hours in an oven brought to a temperature between 50 ° C. and 150 °.
• the calcination of the impregnated and dried support can be carried out in air, preferably a purified air such as purified air according to the process of the present invention.
• the metal salt in aqueous solution can be a halide, in particular a chloride, but advantageously the metal salt in aqueous solution is a nitrate.
• the catalytic purification of air to its carbon monoxide and / or hydrogen impurities by contacting the catalytic bed can be carried out at a temperature between -40 ° C and 140 ° C and at a
• the air is brought into contact with the catalytic bed at ambient temperature or a temperature close to the latter. , either at a temperature between -20 ⁇ C and 50 ° C and at pressure
• the contacting of the air and the catalytic bed can be carried out at a temperature between 80 ° C and 120 "C and at a pressure
• the temperature and pressure used are advantageously those of the air at its outlet from the compressor.
• the water content of the air brought into contact with the catalytic bed is the water content of the air brought into contact with the catalytic bed.
• this water content is between 5 and 15 g / Nm of air, (one Nm
• the carbon dioxide content of the air brought into contact with the catalytic bed is generally greater than 300 ppm.
• This elimination of water and carbon dioxide can be carried out in a conventional manner, for example by means of an adsorbent, such as an adsorbent molecular sieve, of the 13 X zeolite type and / or alumina.
• an adsorbent such as an adsorbent molecular sieve, of the 13 X zeolite type and / or alumina.
• the air purified according to the process of the present invention is usually atmospheric air.
• the carbon monoxide and hydrogen contents of the air intended to be treated according to the process of the invention are usually less than 10 ppm, and more generally of the order of 300 ppb to 3 ppm, in each of these impurities .
• the air After purification, according to the method of the invention, the air generally contains less than 10 ppb of hydrogen and less than 5 ppb of carbon monoxide.
• This purified air can then be distilled cryogenically for the preparation of high purity nitrogen, the hydrogen and carbon monoxide contents of which are generally less than 10 ppb and 5 ppb respectively.
• the invention also relates to a device for implementing the method described above.
• Such a device can be that shown in FIG. 1, comprising: a) an air compressor 1, b) a catalytic bed 2 comprising particles of at least one metal chosen from copper, platinum, palladium, l osmium, iridium, ruthenium, rhenium and rhodium, said particles being supported by a chemically inert support at least with respect to water, the inlet of said catalytic bed 2 being connected to the outlet of the compressor d air 1 via a pipe 3, c) an adsorption bed 4 for water and carbon dioxide, the inlet of which is connected to the outlet of the catalytic bed 2 by a pipe 5, d) where appropriate, a cryogenic distillation unit (not shown) communicating with the outlet of the adsorption bed 4.
• a catalytic bed 2 comprising particles of at least one metal chosen from copper, platinum, palladium, l osmium, iridium, ruthenium, rhenium and rhodium, said particles being supported by
• a variant of this device may consist of the device shown in FIG. 2.
• the latter comprises: a) a catalytic bed 12 comprising particles of at least one metal chosen from copper, platinum, palladium, osmium, Virridiu, ruthenium, rhenium and rhodium, said particles being supported by a chemically inert support, at least vis-à-vis water, b) an air compressor 11, the inlet of which is connected to the outlet of said catalytic bed 12 via a pipe 6, c) an adsorption bed 14 of water and carbon dioxide, the inlet of which is connected to the outlet of said air compressor 11 via a pipe 7, d) the if necessary, a cryogenic distillation unit (not shown) communicating with the outlet of the adsorption bed 14.
• a catalytic bed 12 comprising particles of at least one metal chosen from copper, platinum, palladium, osmium, Virridiu, ruthenium, rhenium and rhodium, said particles being
• the device according to the invention is usually added with means 8, 9, 18, 19 for cooling the air. .
• This means is disposed upstream of the adsorption beds, and downstream of the catalytic bed 2 in the case of the device shown in FIG. 1, or of the air compressor 11 in the case of the device shown in FIG. 2.
• a means can for example consist of a water tower 8, 18, a cooling unit 9, 19, or preferably, a water tower 8, 18 associated with a cooling unit 9, 19.
• the water tower is advantageously arranged upstream of the refrigeration unit.
• the nature of the catalytic bed and the adsorbent bed is as defined above.
• a pore volume of 0.45 cm / g and a pore radius of 2.72 nm are calcined for 8 hours at 800 ° C. under a nitrogen atmosphere. After calcination, the specific surface of the alumina beads is 10 2 m / g. These beads are then impregnated with an aqueous solution to
• the beads are dried in an oven at 100 ° C for 24 hours, then calcined at 500 ° C in air.
• the palladium particles are then reduced by sweeping with a gas mixture consisting, by volume, of 10% hydrogen and 90% nitrogen.
• the catalytic bed thus prepared comprises 0.5% by weight of palladium particles.
• the air to be distilled contains less than 10 ppb of hydrogen and less than 3 ppb of carbon monoxide.
• This purified air is then sent to a double bed consisting of alumina and a 13 X zeolite for the purpose of removal by adsorption at room temperature of water and carbon dioxide.
• Air to be distilled comprising 2 ppm of hydrogen, 2 ppm of
• Alumina has a pore radius of 4.6 nm and a specific surface 2 of 250 m / g.
• the air cleaning is done at 160 ⁇ C and at
• the air still contains 150 ppb of hydrogen and 5 ppb of carbon monoxide.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• Analytical Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Thermal Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Health & Medical Sciences (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Biomedical Technology (AREA)
• General Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Catalysts (AREA)
• Exhaust Gas Treatment By Means Of Catalyst (AREA)
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• 1992
  • 1992-04-24 FR FR929205051A patent/FR2690357B1/fr not_active Expired - Fee Related
• 1993
  • 1993-10-29 JP JP7512435A patent/JPH08508236A/ja active Pending
  • 1993-10-29 WO PCT/FR1993/001074 patent/WO1995011856A1/fr not_active Ceased
  • 1993-10-29 EP EP93924661A patent/EP0677023A1/de not_active Withdrawn

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