GB2151597A - Recovery of carbon dioxide from gas mixtures - Google Patents

Recovery of carbon dioxide from gas mixtures Download PDF

Info

Publication number
GB2151597A
GB2151597A GB08333628A GB8333628A GB2151597A GB 2151597 A GB2151597 A GB 2151597A GB 08333628 A GB08333628 A GB 08333628A GB 8333628 A GB8333628 A GB 8333628A GB 2151597 A GB2151597 A GB 2151597A
Authority
GB
United Kingdom
Prior art keywords
carbon dioxide
gas
mixture
membrane separation
distillation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB08333628A
Other versions
GB8333628D0 (en
GB2151597B (en
Inventor
Melvyn Duckett
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.)
Petrocarbon Developments Ltd
Original Assignee
Petrocarbon Developments Ltd
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 Petrocarbon Developments Ltd filed Critical Petrocarbon Developments Ltd
Priority to GB08333628A priority Critical patent/GB2151597B/en
Publication of GB8333628D0 publication Critical patent/GB8333628D0/en
Priority to AU36569/84A priority patent/AU566452B2/en
Priority to CA000470079A priority patent/CA1236766A/en
Priority to US06/755,374 priority patent/US4639257A/en
Publication of GB2151597A publication Critical patent/GB2151597A/en
Application granted granted Critical
Publication of GB2151597B publication Critical patent/GB2151597B/en
Expired 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
    • F25J3/0228—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 characterised by the separated product stream
    • F25J3/0266—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 characterised by the separated product stream separation of carbon dioxide
    • 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
    • B01D53/229—Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption)
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/50—Carbon dioxide
    • 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
    • F25J3/0204—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 characterised by the feed stream
    • F25J3/0209—Natural gas or substitute natural 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
    • 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
    • F25J3/0228—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 characterised by the separated product stream
    • F25J3/0233—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 characterised by the separated product stream separation of CnHm with 1 carbon atom or more
    • 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
    • F25J3/0228—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 characterised by the separated product stream
    • F25J3/0257—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 characterised by the separated product stream separation of nitrogen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • 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
    • F25J2200/74—Refluxing the column with at least a part of the partially 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
    • F25J2205/02—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum
    • 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
    • F25J2205/40—Processes or apparatus using other separation and/or other processing means using hybrid system, i.e. combining cryogenic 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
    • F25J2205/00—Processes or apparatus using other separation and/or other processing means
    • F25J2205/60—Processes or apparatus using other separation and/or other processing means using adsorption on solid adsorbents, e.g. by temperature-swing adsorption [TSA] at the hot or cold end
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • 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
    • F25J2215/00—Processes characterised by the type or other details of the product stream
    • F25J2215/80—Carbon dioxide
    • 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
    • F25J2220/80—Separating impurities from carbon dioxide, e.g. H2O or water-soluble contaminants
    • F25J2220/82—Separating low boiling, i.e. more volatile components, e.g. He, H2, CO, Air gases, CH4
    • 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
    • F25J2245/02—Recycle of a stream in general, e.g. a by-pass stream
    • 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
    • F25J2270/90—External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration
    • 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
    • Y02C20/40—Capture or disposal of greenhouse gases of CO2
    • 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

Abstract

A process for the recovery of carbon dioxide from a gas mixture in which it is of a concentration not greater than the equilibrium concentration at the freezing temperature of the mixture, comprising (i) concentrating the carbondioxide to a level between its equilibrium concentration and 98% by volume of the mixture by membrane separation and (ii) thereafter distilling the concentrate at sub-ambient temperature and recovering carbon dioxide as a liquid bottoms product of the distillation.

Description

SPECIFICATION Recovery of carbon dioxide from gas mixtures This invention relates to the recovery of carbon dioxide from gas mixtures and is particularly concerned with the treatment of gas mixtures in which the carbon dioxide is present in an amount below the equilibrium concentration at the freezing point of the mixture.
Processes for the recovery, purification and liquefaction of carbon dioxide from carbon dioxide rich streams e.g. fermentation gas and off gases from chemical processes such as ethylene oxide production or ammonia production, are well known. These processes normally carry out the final purification (involving removal of light gases such as hydrogen, nitrogen, oxygen, methane and carbon monoxide) either by cooling and partial condensation of the gas, thus producing a liquid enriched in carbon dioxide and a tail gas lean in carbon dioxide, or by cooling and distillation if a purer carbon dioxide product e.g. greater than 99% pure, by volume, is required.
Such processes are limited by the fact that gas mixtures containing carbon dioxide have a relatively high freezing point. Pure carbon dioxide freezes at a temperature of 21 6.4'K and while this temperature may change depending on the other components in the mixture and the pressure, it is still the factor which determines the degree of separation which can be achieved.
If a gas mixture contains less than the equilibrium concentration of carbon dioxide at the freezing temperature of the mixture concerned then the carbon dioxide cannot be separated by cooling and partial condensation or by cooling and distillation, since the carbon dioxide will freeze before any liquid is formed. This is illustrated in Fig. 1 which shows the dewpoint curves for nitrogen/carbon dioxide mixtures, and Fig. 2 which shows a typical temperature composition diagram for nitrogen/carbon dioxide mixtures at various pressures. At a pressure of 20 bar, for example, the equilibrium carbon dioxide content of the vapour at the freezing temperature of 21 6.5 K is approximately 30% by volume.This means that at a pressure of 20 bar, gaseous mixtures of nitrogen/carbon dioxide which contain less than approximately 30% by volume carbon dioxide cannot be separated by cooling followed by partial condensation or distillation.
Many gases exist where the carbon dioxide content of the gas is low and purification directly by cooling and partial condensation cannot be achieved directly due to freezing problems, e.g.
lime kiln gas, boiler flue gas and certain natural gases.
A solution to this problem, which is used commercially, so to scrub the gas mixture which is lean in carbon dioxide with a suitable solvent, e.g. monoethanolamine, sulfolane or potassium carbonate, whereby to dissolve the carbon dioxide and then to strip the carbon dioxide from the solution so obtained; i.e. another fluid is introduced into the system in order to achieve the necessary separation. The carbon dioxide can then be compressed, dried, cooled and further purified by partial condensation or distillation. However this process is expensive in energy and a less energy-intensive alternative would be desirable.
An alternative method of separating gases that has recently found commercial success is the membrane separation process which involves passing the mixture to be separated at superatmospheric pressure over a semi-permeable membrane across which a pressure drop is maintained and through which one or more of the components of the gas mixture is selectively permeable. This technique has already been proposed for the rem#oval of carbon dioxide as an undesirable impurity from a gas stream, and also for the separation of carbon dioxide from an oil well stream for recycle to the oil well to assist recovery of oil. In neither case, however, is the purity of the separated carbon dioxide stream a matter of importance.
Although it would be possible theoretically to-recover carbon dioxide in a high degree of purity, e.g. 99% or more pure, from a gas mixture by membrane separation, this would be uneconomical because of the high pressure and/or number of separation steps that would be required.
It has now been found unexpectedly that carbon dioxide can be recovered economically and at a high level of purity, e.g. 99% by volume or purer, from a gas mixture which contains the carbon dioxide in a concentration at or below the equilibrium concentration at the freezing point of the mixture, by combination of membrane separation and distillation under certain conditions.
According to the present invention, there is provided a process for the recovery of carbon dioxide from a gas mixture-containing it in a concentration not greater than the equilibrium concentration at the freezing temperature of the mixture, the process comprising concentrating the carbon dioxide in the mixture to a level between said equilibrium concentration and 98% (by volume) of the mixture by membrane separation and thereafter distilling the concentrate at subambient temperature and recovering carbon dioxide as a liquid bottoms product of the distillation.
While the process can be operated satisfactorily with the carbon dioxide content of the gas (concentrate) recovered from the membrane separation as low as 40% or 50%, by volume, the best results from an economical point of view are obtained when the gas contains at least 85% and more preferably at least 90% carbon dioxide, by volume. Carbon dioxide can then be recovered at levels of purity similar to those achievable by the known process of solvent extraction and distillation but with an energy saving which can be as much as 20% or even more in some cases, especially if the overhead stream (i.e. tail gas) from the distillation step is recycled to the membrane separation step.
While the membrane separation may be operated in a single step, it is preferred to employ at least two steps with the carbon dioxide-enriched permeate of the first being subjected to a second separation. if necessary with intermediate recompression. While more than two steps may be employed, if desired, the further improvement so obtained is not so great. Where the membrane separation involves more than one separation step, any recycle of the overhead stream from the distillation column may be to the first or a subsequent step of the membrane separation, as desired. In some cases, such recycle may be desirable not only to optimise carbon dioxide recovery but also to recover one or more other components of the feed gas stream which are retained in said overhead stream from the distillation column.
Any suitable membrane may be employed but it is preferred to use those wherein the carbon dioxide permeability is at least 10 times that of the gas or gases from which it is to be separated under the chosen separation conditions. Examples of suitable membranes are those formed from polysulphone or cellulose acetate.
The invention is particularly applicable to the treatment of gases which contain carbon dioxide in a mixture with nitrogen and/or methane optionally together with other hydrocarbons, e.g.
ethane, propane and/or butane.
The invention is now described in more detail with reference to one preferred embodiment and with the aid of Fig. 3 of the accompanying drawings which is a flow diagram of the process.
Referring to Fig. 3, 1 and 5 are membrane separation units, 2 and 6 are compressors, 3 and 8 are coolers, 4 and 8 are gas/liquid separators, 9 is an adsorber unit, 10 is a distillation column, 11 is a reboiler, 12 is a condenser and 13 is a refrigeration unit.
The carbon dioxide-containing feed gas mixture, at a suitably elevated pressure, is provided through pipeline 20 to membrane separation unit 1, where it is separated into a carbon dioxiderich permeate which is recovered through line 22 and a tail gas which is lean in carbon dioxide and which is recovered through line 24. The gas in line 22 is then supplied to membrane unit 5. If it is recovered from membrane unit 1 at a pressure below the desired inlet pressure to membrane unit 5, it is first recompressed in compressor 2 and then cooled in cooler 3. any condensate thereby formed being separated in gas/liquid separator 4 and the resultant gas being supplied to membrane unit 5 through pipeline 26.
In membrane unit 5, further carbon dioxide-enrichment occurs with the carbon dioxide-rich stream being recovered through pipeline 28 and the lean gas stream being recovered through pipeline 30.
The gas in pipeline 28 is then supplied to distillation column 10. If the pressure at which it is recovered from the membrane separation unit 5 is below the desired distillation pressure, the gas is first recompressed in compressor 6, cooled in cooler 7 and any condensate so formed is separated in gas/liquid separator 8. Further drying can be carried out, if desired, by passing the gas through adsorber unit 9. The gas is then cooled to the desired distillation temperature by passage through distillation column reboiler 11 and then fed to an intermediate point in the distillation column. High purity carbon dioxide liquid, e.g. 99% or more pure, is recovered from the bottom of the column in pipeline 32 and the tail gas is recovered in pipeline 34 and returned to be combined with the feed gas in pipeline 26 to the second membrane unit 5. In the embodiment illustrated, the cooling for the condenser of the distillation column is provided by a vapour compression refrigeration unit 13 but other cooling means may also be used.
EXAMPLE Using the process described above with reference to Fig. 3 of the drawings, the recovery of a substantially 100% carbon dioxide liquid stream from a gas stream comprising 88 mole% methane and 12 mole% carbon dioxide and supplied at a pressure of 28.6 bar and a temperature of 300 K required an energy consumption of 1936 Kcals/Nm3 of liquid carbon dioxide produced.
The details of temperature, pressure and composition of the gas streams in the various parts of the process are set out in the Table below.
TABLE Flow Composition P Pipeline (Nm3/h) Mole % CH4 Mole % C02 (Bar) TOK 20 100 000 88.0 12.0 28.6 300 24 82 226 97.0 3.0 28.0 310 22 17 774 46.4 53.6 1.5 303 26 19 530 46.4 53.6 27.5 303 28 10 158 8.0 92.0 1.5 300 3,2 8 402 - 100.0 28.0 266 34 1 756 46.4 53.6 27.5 240 30 9 372 88.0 12.0 27.0 303 The energy requirements expressed as Kcals/Nm3 of liquid CO2 produced, were as follows, assuming 30% efficiency for gas engine drives: Compressor 2: 958 Compressor 6: 548 Refrigeration Unit: 410 Carbon Dioxide Dryer 9: 20 Total 1936 By way of comparison, the energy requirements for treating the same stream by the known solvent extraction process employing Sulfinol are 2401 Kcals/Nm3 of liquid carbon dioxide produced and the energy requirements for treating the same stream by a conventional solvent extraction process employing a mixture of mono- and di-ethanolamine are 4379 Kcals/Nm3 of liquid carbon dioxide produced.

Claims (8)

1. A process for the recovery of carbon dioxide from a gas mixture containing it in a concentration not greater than the equilibrium concentration at the freezing temperature of the mixture, the process comprising concentrating the carbon dioxide in the mixture to a level between said equilibrium concentration and 98% (by volume) of the mixture by membrane separation and thereafter distilling the concentrate at sub-ambient temperature and recovering carbon dioxide as a liquid bottoms product of the distillation.
2. A process as claimed in claim 1 in which the carbon dioxide content of the concentrate obtained by membrane separation is at least 85% by volume.
3. A process as claimed in claim 1 in which the carbon dioxide content of the concentrate obtained by membrane separation is at least 90% by volume.
4. A process as claimed in any of claims 1 to 3 in which the membrane separation step involves the use of at least two membranes in series optionally with repressurisation of the gas between each membrane.
5. A process as claimed in any one of claims 1 to 4 in which the overhead stream from the distillation is recycled to the first or a subsequent membrane of the membrane separation step.
6. A process as claimed in any one of claims 1 to 5 in which the gas mixture also contains nitrogen.
7. A process as claimed in any one of claims 1 to 5 in which the gas mixture also contains at least one hydrocarbon.
8. A process as claimed in claim 7 in which the gas mixture also contains methane.
GB08333628A 1983-12-16 1983-12-16 Recovery of carbon dioxide from gas mixtures Expired GB2151597B (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
GB08333628A GB2151597B (en) 1983-12-16 1983-12-16 Recovery of carbon dioxide from gas mixtures
AU36569/84A AU566452B2 (en) 1983-12-16 1984-12-12 Recovery of co2 from gas mixtures
CA000470079A CA1236766A (en) 1983-12-16 1984-12-13 Recovery of carbon dioxide from gas mixtures
US06/755,374 US4639257A (en) 1983-12-16 1985-07-15 Recovery of carbon dioxide from gas mixture

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08333628A GB2151597B (en) 1983-12-16 1983-12-16 Recovery of carbon dioxide from gas mixtures

Publications (3)

Publication Number Publication Date
GB8333628D0 GB8333628D0 (en) 1984-01-25
GB2151597A true GB2151597A (en) 1985-07-24
GB2151597B GB2151597B (en) 1987-09-30

Family

ID=10553429

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08333628A Expired GB2151597B (en) 1983-12-16 1983-12-16 Recovery of carbon dioxide from gas mixtures

Country Status (3)

Country Link
AU (1) AU566452B2 (en)
CA (1) CA1236766A (en)
GB (1) GB2151597B (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2174379A (en) * 1985-03-27 1986-11-05 Costain Petrocarbon Process for recovering carbon dioxide
EP0965564A1 (en) * 1998-06-17 1999-12-22 Praxair Technology, Inc. Carbon dioxide production system with integral vent gas condenser
US6085549A (en) * 1998-04-08 2000-07-11 Messer Griesheim Industries, Inc. Membrane process for producing carbon dioxide
US6128919A (en) * 1998-04-08 2000-10-10 Messer Griesheim Industries, Inc. Process for separating natural gas and carbon dioxide
EP1953486A1 (en) 2007-01-23 2008-08-06 Air Products and Chemicals, Inc. Purification of carbon dioxide
WO2008099344A1 (en) * 2007-02-16 2008-08-21 L'air Liquide-Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Process for recycling of top gas during co2 separation
EP2138786A1 (en) 2007-01-23 2009-12-30 Air Products and Chemicals, Inc. Purification of Carbon Dioxide
US8080090B2 (en) 2007-02-16 2011-12-20 Air Liquide Process & Construction, Inc. Process for feed gas cooling in reboiler during CO2 separation
US8088196B2 (en) 2007-01-23 2012-01-03 Air Products And Chemicals, Inc. Purification of carbon dioxide

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1108512A (en) * 1965-06-24 1968-04-03 Atomic Energy Authority Uk Improvements relating to gas-cooled nuclear reactors
GB1471699A (en) * 1973-06-13 1977-04-27 Rhone Poulenc Sa Partially crosslinked silalactone polymers their preparation and their use
GB1590813A (en) * 1976-11-15 1981-06-10 Monsanto Co Multicomponent membranes

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1108512A (en) * 1965-06-24 1968-04-03 Atomic Energy Authority Uk Improvements relating to gas-cooled nuclear reactors
GB1471699A (en) * 1973-06-13 1977-04-27 Rhone Poulenc Sa Partially crosslinked silalactone polymers their preparation and their use
GB1590813A (en) * 1976-11-15 1981-06-10 Monsanto Co Multicomponent membranes

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2174379A (en) * 1985-03-27 1986-11-05 Costain Petrocarbon Process for recovering carbon dioxide
US6085549A (en) * 1998-04-08 2000-07-11 Messer Griesheim Industries, Inc. Membrane process for producing carbon dioxide
US6128919A (en) * 1998-04-08 2000-10-10 Messer Griesheim Industries, Inc. Process for separating natural gas and carbon dioxide
EP0965564A1 (en) * 1998-06-17 1999-12-22 Praxair Technology, Inc. Carbon dioxide production system with integral vent gas condenser
EP2138786A1 (en) 2007-01-23 2009-12-30 Air Products and Chemicals, Inc. Purification of Carbon Dioxide
EP1953486A1 (en) 2007-01-23 2008-08-06 Air Products and Chemicals, Inc. Purification of carbon dioxide
US7819951B2 (en) 2007-01-23 2010-10-26 Air Products And Chemicals, Inc. Purification of carbon dioxide
US7850763B2 (en) 2007-01-23 2010-12-14 Air Products And Chemicals, Inc. Purification of carbon dioxide
US8088196B2 (en) 2007-01-23 2012-01-03 Air Products And Chemicals, Inc. Purification of carbon dioxide
US8257476B2 (en) 2007-01-23 2012-09-04 Air Products And Chemicals, Inc. Purification of carbon dioxide
US8900355B2 (en) 2007-01-23 2014-12-02 Air Products And Chemicals, Inc. Purification of carbon dioxide
WO2008099344A1 (en) * 2007-02-16 2008-08-21 L'air Liquide-Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Process for recycling of top gas during co2 separation
US8080090B2 (en) 2007-02-16 2011-12-20 Air Liquide Process & Construction, Inc. Process for feed gas cooling in reboiler during CO2 separation

Also Published As

Publication number Publication date
CA1236766A (en) 1988-05-17
GB8333628D0 (en) 1984-01-25
AU566452B2 (en) 1987-10-22
AU3656984A (en) 1986-06-19
GB2151597B (en) 1987-09-30

Similar Documents

Publication Publication Date Title
US4639257A (en) Recovery of carbon dioxide from gas mixture
US4589896A (en) Process for separating CO2 and H2 S from hydrocarbons
US6128919A (en) Process for separating natural gas and carbon dioxide
US4242108A (en) Hydrogen sulfide concentrator for acid gas removal systems
US8337587B2 (en) Carbon dioxide purification
EP0186843B1 (en) Integrated gas separation process
US4747858A (en) Process for removal of carbon dioxide from mixtures containing carbon dioxide and methane
US4654047A (en) Hybrid membrane/cryogenic process for hydrogen purification
US4595405A (en) Process for the generation of gaseous and/or liquid nitrogen
US4701187A (en) Process for separating components of a gas stream
US4681612A (en) Process for the separation of landfill gas
AU622091B2 (en) Recovery of carbon dioxide from a carbon dioxide plant vent gas using membranes
EP1953486B1 (en) Purification of carbon dioxide
US4717407A (en) Process for recovering helium from a multi-component gas stream
US4936887A (en) Distillation plus membrane processing of gas streams
US4374657A (en) Process of separating acid gases from hydrocarbons
WO1981002291A1 (en) Method for purifying a gas mixture
GB2174379A (en) Process for recovering carbon dioxide
US7380413B2 (en) Method and installation for separating a mixture of hydrogen and carbon monoxide
US5979178A (en) Process for recovering olefins from cracked gases
US4533373A (en) Separation of CO2 and H2 S from hydrogen containing gas
CN116710397A (en) Enhanced hydrogen recovery using gas separation membranes integrated with pressure swing adsorption units and/or cryogenic separation systems
GB2151597A (en) Recovery of carbon dioxide from gas mixtures
US5693121A (en) Semi-permeable membrane separation process for the production of very high purity nitrogen
EP3067315B1 (en) Light gas separation process and system

Legal Events

Date Code Title Description
746 Register noted 'licences of right' (sect. 46/1977)
747B Proceeding under sect. 47(1) patents act 1977
747C Notice that the entry in the register 'licence of right' was cancelled (sect. 47/1977)
PE20 Patent expired after termination of 20 years

Effective date: 20031215