Classifications

• • 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
  • B01D53/8678—Removing components of undefined structure
  • B01D53/8687—Organic components
• • 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
• • 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
  • B01D53/002—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 condensation
• • 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
  • B01D53/8659—Removing halogens or halogen compounds
  • B01D53/8662—Organic halogen compounds
• • 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
  • B01D53/8678—Removing components of undefined structure
  • B01D53/8681—Acidic components
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/10—Noble metals or compounds thereof
  • B01D2255/102—Platinum group metals
  • B01D2255/1021—Platinum
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2255/00—Catalysts
  • B01D2255/10—Noble metals or compounds thereof
  • B01D2255/102—Platinum group metals
  • B01D2255/1023—Palladium
• • 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
  • B01D2256/22—Carbon dioxide
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2257/00—Components to be removed
  • B01D2257/20—Halogens or halogen compounds
  • B01D2257/204—Inorganic halogen compounds
  • B01D2257/2045—Hydrochloric acid
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2257/00—Components to be removed
  • B01D2257/20—Halogens or halogen compounds
  • B01D2257/204—Inorganic halogen compounds
  • B01D2257/2047—Hydrofluoric acid
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2257/00—Components to be removed
  • B01D2257/30—Sulfur compounds
  • B01D2257/302—Sulfur oxides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2257/00—Components to be removed
  • B01D2257/40—Nitrogen compounds
  • B01D2257/404—Nitrogen oxides other than dinitrogen oxide
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2259/00—Type of treatment
  • B01D2259/40—Further details for adsorption processes and devices
  • B01D2259/416—Further details for adsorption processes and devices involving cryogenic temperature treatment
• • 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
  • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
  • Y02C20/00—Capture or disposal of greenhouse gases
  • Y02C20/30—Capture or disposal of greenhouse gases of perfluorocarbons [PFC], hydrofluorocarbons [HFC] or sulfur hexafluoride [SF6]

Definitions

• the present invention relates to a method and a plant for purifying a feed gas stream comprising at least 90% CO 2, preferably 95% CO 2.
• Carbon dioxide is used in various applications, for example for the food market, which requires that CO2 contain very low levels of impurities.
• the International Society of Beverage Technologists (ISBT) requires the following composition:
• Oxygen 30 ppm v / v max.
• Carbon monoxide 10 ppm v / v max.
• Non-volatile residue 10 ppm w / w max.
• Nonvolatile organic residue 5 ppm w / w max.
• Total volatile hydrocarbons (such as methane) 50 ppm v / v max. with 20 ppm v / v max. for total non-methane hydrocarbons
• Acetaldehyde 0.2 ppm v / v max.
• the CO2-rich feed stream can come from a variety of sources, such as ammonia plants, natural wells, bio-fermentation, syngas production units, and the like. ... containing various traces of impurities, including hydrocarbons, sulfur compounds, nitrous compounds, chlorinated compounds and many other impurities which must be efficiently and economically removed.
• Catox catalytic oxidation
• the wet separator is a common solution that can be adapted to high levels of impurities. It consists of passing the feed gas through a medium promoting fluidic contact, for example a structured or random packaging, inside a container. Water is sprayed or dispensed onto the top of the container. If this solution seems effective in removing water-soluble hydrocarbon-containing hydrocarbons such as, for example, ethanol and methanol from feed streams, it is not effective in removing hydrocarbons that are not soluble in water. water, whose solubility in water is very low. Another disadvantage is that water must be introduced into the system. For the food-grade CO2 production area, this water must consume drinking water. Such water may not be available or at a high cost in an industrial plant.
• the basic anions of the hydroxyl group, carbonate or bicarbonate are introduced in a solid (milled) or liquid form into the feed gas.
• Basic anions react with acid gases to form salts.
• the salts are then filtered in a bag filter or separated in a container.
• the disadvantage of this solution is that it is not referenced for high efficiency removal. Its classic application is the treatment of flue gases, in order to comply with environmental standards. These standards are much less demanding than those applied for food C0 2 .
• this solution involves the addition of an external component.
• Handling chemical reagent such as sodium hydroxide requires special care and additional equipment (storage, dosing system).
• storage, dosing system For example, the use of sodium bicarbonate entails strong constraints. Indeed, this solution must be used at a temperature between 140 ° C and 300 ° C.
• Adsorption beds may be based on physical adsorption.
• the low adsorption force implies easy regeneration, but also fairly low or moderate adsorption capacities.
• it allows a regenerative process, having a long life, on the other hand, it may require high amounts of adsorbents detrimental to the cost or very fast cycle times (time including adsorption then the regeneration steps) implying that large amounts of regeneration gas are available.
• a problem is to provide an improved and economical method of purifying a feed gas stream comprising at least 90% CO 2.
• a solution of the present invention is a process for purifying a feed gas stream comprising at least 90% CO2, preferably at least 95% CO 2, at least 20% relative humidity and at least one impurity selected from chlorinated, sulfur-containing, nitrated or fluorinated compounds comprising the following successive steps:
• step c) a step of removing at least a portion of the acid impurities by contacting the gas stream from step b) in contact with at least one corrosion-resistant heat exchanger so as to condense the acidic compounds while regulating the temperature of the gas stream leaving under the dew point of the water;
• step d) a step of separating the acidic compounds of the gas stream from step c) by means of a corrosion-resistant separator so as to produce a gas stream enriched with CO2.
• Step b) avoids any creation of acidic liquid which corrodes the piping and other standard materials. It will be ensured never to pass below the critical dew point via suitable operating conditions but also thanks to a thermal insulation or even an external temperature maintenance system (electric or steam) preventing the creation of cold spots (temperature locally below the critical dew point) on the equipment.
• step c) if the composition of the feed gas of the catalytic process varies, it will be possible to regulate the outlet temperature of the indirect contact condenser of the plate or tube / calender type via the liquid / gas flow of cooling the supply or via the temperature of it.
• the method according to the invention may have one or more of the following characteristics:
• step d said process comprises, after step d), the following successive steps:
• the drying is generally carried out via a reversible adsorption unit making it possible to reach water contents compatible with the cryogenic temperature in question ( ⁇ 10 ppmv and preferably ⁇ 1 ppmv).
• the heat exchanger and the separator are made of materials selected from austenitic steel, glass or a composite resistant to nitric acid, sulfuric or hydrochloric acid.
• the catalytic oxidation is carried out by means of a catalytic oxidation unit whose catalyst is tolerant of sulfur and chlorine.
• the feed gas stream subjected to the catalytic oxidation is at a temperature of at least 300 ° C., preferably at least 425 ° C.
• the feed gas stream subjected to catalytic oxidation is at a pressure greater than 1 bar absolute
• the feed gas stream can come from various sources such as the monoethylene glycol production units or bio-fermentors
• step c) water or a water / glycol mixture is preferably used as a refrigerant within the heat exchanger.
• the water heated in the heat exchanger by the gas stream is in a closed circuit and is cooled in a second ammonia / water heat exchanger.
• the present invention also relates to an installation for purifying a feed gas stream comprising at least 95% CO 2, at least 20% relative humidity and at least one impurity selected from chlorinated compounds, sulfur, nitrated or fluorinated, comprising in the flow direction of the gaseous flow:
• a catalytic oxidation unit for subjecting the gas stream to catalytic oxidation so as to produce a gas stream comprising at least one acidic impurity selected from HCl, NOx and SOx;
• step d) a corrosion resistant separator for separating the acidic compounds from the gas stream so as to produce a gas stream enriched with CO2.
• a corrosion resistant drum separator will be used.
• the separator is equipped with an automatic draining system.
• the installation according to the invention may have one or more of the following characteristics:
• said plant comprises downstream of the separator and in the direction of flow of the gas stream enriched in CO2:
• the heat exchanger and the separator are made of materials selected from austenitic steel, glass or a composite resistant to nitric acid, sulfuric or hydrochloric acid.
• materials selected from austenitic steel, glass or a composite resistant to nitric acid, sulfuric or hydrochloric acid.
• 254SMO and 904L steels nickel-based alloys or titanium.
• the heat exchanger is made of 254 SMO stainless steel for the parts in contact with the process gas, the rest being SS 316L steel, specially designed for strong corrosion created by the Hcl.
• the catalytic oxidation is carried out by means of a sulfur and chlorine-resistant catalytic oxidation unit.
• the stream is contacted with a catalyst bed containing a first layer of platinum catalyst and a second layer of palladium catalyst, making it possible to convert most of the hydrocarbons into water and carbon dioxide.
• a catalyst bed containing a first layer of platinum catalyst and a second layer of palladium catalyst, making it possible to convert most of the hydrocarbons into water and carbon dioxide.
• the gaseous flow at a temperature above 300 ° C. and containing HCl is cooled to a temperature above the dew point of the water (43 ° C.), in order to prevent condensation.
• the fluid at a temperature of 55 ° C., will then be fed into a skid comprising a heat exchanger made of a material resistant to chloridic acid, such as steel grade 254SMO.
• the cold will be brought into the exchanger through a coolant such as water, at a temperature below 43 ° C, preferably below 10 ° C to minimize the size of the exchanger. Cooling water supplying the exchanger
• the separation of the liquid droplets containing the acid molecules will be ensured by a separator pot (installed directly downstream of the exchanger) in a material resistant to corrosion by chlorine such as steel grade 254 SMO or more simply by a material made of polymer resin.
• the process gas leaving the separator pot and the condensed liquid, purged at the bottom of the separator pot will have the following compositions:
• AcetAldehyde 0.000000 0.000000

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• Analytical Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Biomedical Technology (AREA)
• Drying Of Gases (AREA)
• Gas Separation By Absorption (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 2017
  • 2017-08-10 FR FR1757639A patent/FR3070016B1/fr active Active
• 2018
  • 2018-07-13 SG SG11202000945VA patent/SG11202000945VA/en unknown
  • 2018-07-13 RU RU2020109294A patent/RU2734348C1/ru active
  • 2018-07-13 EP EP18773788.7A patent/EP3664917A1/fr active Pending
  • 2018-07-13 WO PCT/FR2018/051788 patent/WO2019030437A1/fr unknown
  • 2018-07-13 US US16/637,978 patent/US11400413B2/en active Active
  • 2018-07-13 CN CN201880058643.8A patent/CN111065445A/zh active Pending

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