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US4609388A
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Gas separation process
Assignee: Acrion Technologies Inc
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Filing: 1985-05-24
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Granted: 1986-09-02
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Expires: 2005-05-24
Abstract
Abstract A process for separating acid gases such as CO 2 , H 2 S, and SO 2 , other sulfur-containing molecules such as COS, and other relatively high boiling point impurities from lower boiling point components of a gas stream comprises: dehydrating the gas stream and contacting it, at an elevated pressure and at substantially the dew point temperature of carbon dioxide therein, with a liquid carbon dioxide refrigerant-absorbent to absorb such impurities other than CO 2 , and separating the liquid carbon dioxide and absorbed impurities; condensing CO 2 , and separating the liquid carbon dioxide and absorbed impurities; and condensing CO 2 from the residual gas stream at such pressure, preferably by indirect heat exchange. A crystallization process is also disclosed for separating the liquid carbon dioxide and absorbed impurities. The residual gas stream obtained following indirect heat exchange may be processed further by contact with a second refrigerant-absorbent which preferably comprises a liquid-solid slurry. Further, a crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid mixture of the materials. The solid phase is formed and melted at spaced locations in a liquid mixture of the materials and, within the liquid mixture, internal solid and liquid flows are maintained in opposite directions to effect separation of the materials. The solid phase is formed by evaporative cooling of the liquid mixture and melted by direct contact with a condensing vapor phase of the materials, each of these operations being performed substantially at the prevailing triple point locus conditions in the respective locations in the liquid mixture.
Inventors
- 👤 Robert J. Adler
- 👤 Coleman B. Brosilow
- 👤 William R. Brown
- 👤 Nelson C. Gardner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:29
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/14; B; B01; B01D; B01D9/00; B01D9/0059; C01; C01B; C01B32/00; C01B32/50; C01B32/55; Y; Y10; Y10S; Y10S62/00; Y10S62/928
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
91 words
A process for the removal of contaminant gas molecules from a gas stream, comprising the steps of: (1) contacting the gas stream in countercurrent flow with a liquid carbon dioxide absorbent to absorb and entrain the contaminant molecules; (2) separating a substantially decontaminated residual gas stream from a mixture of the carbon dioxide absorbent and absorbed contaminant molecules; (3) separating the carbon dioxide absorbent and concentrating the contaminant molecules of said mixture by crystallization; and (4) reusing at least part of the separated carbon dioxide absorbent as absorbent in step (1).
Claim 2
Dependent Claim
91 words
A process for the removal of contaminant gas molecules from a gas stream, comprising the steps of: (1) contacting the gas stream in countercurrent flow with a liquid carbon dioxide absorbent to absorb and entrain the contaminant molecules; (2) separating a substantially decontaminated residual gas stream from a mixture of the carbon dioxide absorbent and absorbed contaminant molecules; (3) separating the carbon dioxide absorbent and concentrating the contaminant molecules of said mixture by crystallization; and (4) reusing at least part of the separated carbon dioxide absorbent as absorbent in step (1).
Claim 3
Dependent Claim
115 words
A process as set forth in claim 1, wherein said crystallization of step (3) comprises performing in each of one or more separation stages, comprising the steps of: (a) forming a liquid mixture of said carbon dioxide absorbent and absorbed contaminant molecules; (b) forming a solid phase containing said carbon dioxide absorbent and at least partially excluding said absorbed contaminant molecules by evaporating said liquid mixture; (c) melting said solid phase by direct heat transfer with a condensing vapor; and (d) moving said separated carbon dioxide absorbent in a first flow direction to provide a carbon dioxide absorbent-enriched output and moving said contaminant molecules in a second flow direction to provide a contaminant molecule-enriched output.
Claim 4
Dependent Claim
23 words
A process as set forth in claim 2, wherein said contaminant gas molecules comprise molecules of at least one or more noble gases.
Claim 5
Dependent Claim
31 words
A process as set forth in claim 2, wherein said contaminant gas molecules comprise molecules of at least one or more gases selected from the group consisting of krypton and xenon.
Claim 6
Dependent Claim
39 words
A process as set forth in claim 2, wherein said condensing vapor is a vapor phase of a carbon dioxide absorbent enriched liquid mixture located in said process remote of the stage wherein said solid phase is being melted.
Claim 7
Dependent Claim
91 words
A process for the removal of sulfur-containing gas molecules from a gas stream, comprising the steps of: (1) contacting the gas stream in countercurrent flow with a liquid carbon dioxide absorbent to absorb and entrain the sulfur-containing molecules; (2) separating a substantially desulfurized residual gas stream from a mixture of the carbon dioxide absorbent and absorbed sulfur-containing molecules; (3) separating the carbon dioxide absorbent and concentrating the sulfur-containing molecules of said mixture by crystallization; and (4) reusing at least part of the separated carbon dioxide absorbent as absorbent in step (1).
Claim 8
Dependent Claim
91 words
A process for the removal of sulfur-containing gas molecules from a gas stream, comprising the steps of: (1) contacting the gas stream in countercurrent flow with a liquid carbon dioxide absorbent to absorb and entrain the sulfur-containing molecules; (2) separating a substantially desulfurized residual gas stream from a mixture of the carbon dioxide absorbent and absorbed sulfur-containing molecules; (3) separating the carbon dioxide absorbent and concentrating the sulfur-containing molecules of said mixture by crystallization; and (4) reusing at least part of the separated carbon dioxide absorbent as absorbent in step (1).
Claim 9
Dependent Claim
114 words
A process as set forth in claim 6, wherein said crystallization of step (3) comprises performing in each of one or more separation stages, the steps of: (a) forming a liquid mixture of said carbon dioxide absorbent and absorbed sulfur-containing molecules; (b) forming a solid phase containing said carbon dioxide absorbent and at least partially excluding said absorbed contaminant molecules by evaporating said liquid mixture; (c) melting said solid phase by direct heat transfer with a condensing vapor; and (d) moving said separated carbon dioxide absorbent in a first flow direction to provide a carbon dioxide absorbent-enriched output and moving said contaminant molecules in a second flow direction to provide a contaminant molecule-enriched output.
Claim 10
Dependent Claim
27 words
A process as set forth in claim 7, wherein substantially all of the heat energy required for melting said solid phase is provided by said condensing vapor.
Claim 11
Dependent Claim
28 words
A process as set forth in claim 7, wherein substantially all of the cooling required to form said solid phase is provided by evaporation of said liquid mixture.
Claim 12
Dependent Claim
28 words
A process as set forth in claims 7, 8, or 9, wherein said condensing vapor is a vapor phase of said carbon dioxide absorbent and absorbed sulfur-containing molecules.
Claim 13
Dependent Claim
47 words
A process as set forth in claim 7, wherein said crystallization step includes a first stage connected in series to a second stage and providing substantially all mass and energy flows between stages as liquid and vapor phases of said carbon dioxide absorbent and absorbed sulfur-containing molecules.
Claim 14
Dependent Claim
63 words
A process as set forth in claim 7, wherein substantially all of the cooling required to form said solid phase is provided by evaporation of said liquid mixture, substantially all of the heat energy required for melting said solid phase is provided by said condensing vapor, and said condensing vapor comprises a vapor phase of said carbon dioxide absorbent and absorbed sulfur-containing molecules.
Claim 15
Dependent Claim
236 words
A process as set forth in claim 12, including forming in said liquid mixture solid and liquid flows of said carbon dioxide absorbent and sulfur-containing molecules in accordance with their respective flow directions and corresponding increasing concentration gradients thereof, performing step (b) in a crystal forming zone of said liquid mixture having a relatively high concentration of said sulfur-containing molecules and at a first operating pressure below the prevailing triple point pressure, performing step (c) in a crystal melting zone of said liquid mixture having a relatively high concentration of said carbon dioxide absorbent and at a second operating pressure above the prevailing triple point pressure, forming a crystal washing zone in said liquid mixture extending between said crystal forming and melting zones, moving said solid phase from said crystal forming zone through said crystal washing zone to said crystal melting zone, melting substantially all of said solid phase to enrich the liquid mixture in said crystal melting zone with carbon dioxide absorbent, withdrawing a portion of the liquid mixture in said crystal melting zone to provide said carbon dioxide absorbent-enriched output, and passing a further portion of the liquid mixture to said crystal washing zone to countercurrently wash said solid phase, and withdrawing said sulfur-containing molecule-enriched output as a component in said evaporation vapor, or as a liquid stream withdrawn from said crystal washing zone or said crystal forming zone, or as a combination thereof.
Claim 16
Dependent Claim
85 words
A process as set forth in claim 13, wherein said crystallization step includes a first stage connected in series to a second stage, passing a carbon dioxide absorbent-enriched output of said first stage as a liquid stream to said second stage to augment a second stage liquid mixture therein, passing a second stage sulfur-containing molecule-enriched output to said first stage to augment a first stage liquid mixture therein and passing a second stage evaporation vapor to said first stage to provide a condensing vapor therein.
Claim 17
Dependent Claim
86 words
A process for the removal of sulfur-containing gas molecules from a feed gas stream, comprising precluding the need to distill the feed gas stream by the steps of: (1) contacting the gas stream in countercurrent flow with a liquid carbon dioxide absorbent to absorb and entrain the sulfur-containing molecules; (2) separating a substantially desulfurized residual gas stream from a mixture of the carbon dioxide absorbent and absorbed sulfur-containing molecules; and (3) separating the carbon dioxide absorbent and concentrating the sulfur-containing molecules of said mixture by crystallization.
Claim 18
Dependent Claim
86 words
A process for the removal of sulfur-containing gas molecules from a feed gas stream, comprising precluding the need to distill the feed gas stream by the steps of: (1) contacting the gas stream in countercurrent flow with a liquid carbon dioxide absorbent to absorb and entrain the sulfur-containing molecules; (2) separating a substantially desulfurized residual gas stream from a mixture of the carbon dioxide absorbent and absorbed sulfur-containing molecules; and (3) separating the carbon dioxide absorbent and concentrating the sulfur-containing molecules of said mixture by crystallization.
Claim 19
Dependent Claim
259 words
A process for treating a feed gas stream comprising relatively high boiling point gases including hydrogen sulfide, carbonyl sulfide, and carbon dioxide and relatively lower boiling point gas of primary value, comprising precluding the need to distill the feed gas stream by the steps of: (a) providing a feed gas stream which is pressurized and cooled to a predetermined pressure and temperature; (b) providing an absorption column and a supply of substantially pure liquid carbon dioxide absorbent at substantially said predetermined pressure and temperature; (c) introducing absorbent from said supply thereof and said feed gas stream into said absorption column for separation of said hydrogen sulfide and carbonyl sulfide from said lower boiling point gas; (d) contacting said feed gas stream in said absorption column with a countercurrent flow of absorbent in an amount sufficient, but not exceeding that required, to absorb and entrain substantially all of said hydrogen sulfide present in the gas stream and thereby also to absorb and entrain substantially all of said carbonyl sulfide in the gas stream while maintaining most of the absorbent in the liquid state at substantially said pressure and temperature, the balance of the absorbent being vaporized by the heat of condensation of the absorbed gas; (e) withdrawing from said absorption column a substantially completely desulfurized residual gas stream containing said relatively lower boiling point gas and a mixture of the still liquid absorbent and gases absorbed or entrained therewith; and (f) recovering substantially pure carbon dioxide from the separated liquid mixture of said absorbent and gases absorbed or entrained therewith.
Claim 20
Dependent Claim
259 words
A process for treating a feed gas stream comprising relatively high boiling point gases including hydrogen sulfide, carbonyl sulfide, and carbon dioxide and relatively lower boiling point gas of primary value, comprising precluding the need to distill the feed gas stream by the steps of: (a) providing a feed gas stream which is pressurized and cooled to a predetermined pressure and temperature; (b) providing an absorption column and a supply of substantially pure liquid carbon dioxide absorbent at substantially said predetermined pressure and temperature; (c) introducing absorbent from said supply thereof and said feed gas stream into said absorption column for separation of said hydrogen sulfide and carbonyl sulfide from said lower boiling point gas; (d) contacting said feed gas stream in said absorption column with a countercurrent flow of absorbent in an amount sufficient, but not exceeding that required, to absorb and entrain substantially all of said hydrogen sulfide present in the gas stream and thereby also to absorb and entrain substantially all of said carbonyl sulfide in the gas stream while maintaining most of the absorbent in the liquid state at substantially said pressure and temperature, the balance of the absorbent being vaporized by the heat of condensation of the absorbed gas; (e) withdrawing from said absorption column a substantially completely desulfurized residual gas stream containing said relatively lower boiling point gas and a mixture of the still liquid absorbent and gases absorbed or entrained therewith; and (f) recovering substantially pure carbon dioxide from the separated liquid mixture of said absorbent and gases absorbed or entrained therewith.
Claim 21
Dependent Claim
52 words
A process according to claim 16, in which both the feed gas stream and liquid carbon dioxide absorbent are brought into contact in step (d) at substantially the same temperature and pressure and said temperature is substantially the dew point temperature of carbon dioxide in the feed gas stream at that pressure.
Claim 22
Dependent Claim
28 words
A process according to claim 16, in which said feed gas stream is provided with a carbon dioxide dew point temperature above the carbon dioxide triple point temperature.
Claim 23
Dependent Claim
45 words
A process according to claim 16, including the step of recovering substantially pure carbon dioxide from said substantially completely desulfurized residual gas stream and returning at least a portion of the recovered carbon dioxide to said absorption column for reuse as absorbent in step (d).
Claim 24
Dependent Claim
51 words
A process according to claim 16, in which the substantially completely desulfurized residual gas stream withdrawn from said absorption column in step (e) is cooled to condense carbon dioxide therefrom and the so-condenzed carbon dioxide reflux is returned to the process and used as part of the absorbent in step (d).
Claim 25
Dependent Claim
48 words
A process according to claim 20, in which step (e) is performed by withdrawing the substantially completely desulfurized residual gas stream from the top of said absorption column and the mixture of still liquid absorbent and the gases absorbed or entrained therewith from the bottom of the column.
Claim 26
Dependent Claim
23 words
A process according to claim 16, in which said relatively lower boiling point gas comprises a major portion of said feed gas stream.
Claim 27
Dependent Claim
51 words
A process according to claim 16, in which said feed gas stream includes at least one additional gas of relatively lower boiling point selected from the group consisting of hydrogen, carbon monoxide, nitrogen, and methane, and said relatively lower boiling point gases comprise a major portion of said feed gas stream.
Claim 28
Dependent Claim
31 words
A process according to claim 16, in which said feed gas stream consists essentially of hydrogen, carbon monoxide, nitrogen, and methane, together with said hydrogen sulfide, carbonyl sulfide, and carbon dioxide.
Claim 29
Dependent Claim
20 words
A process according to claim 16, in which step (a) includes cooling said feed gas stream to said predetermined temperature.
Claim 30
Dependent Claim
259 words
A process for treating a feed gas stream comprising relatively high boiling point gases including hydrogen sulfide, carbonyl sulfide, and carbon dioxide and relatively lower boiling point gas of primary value, comprising precluding the need to distill the feed gas stream by the steps of: (a) providing a feed gas stream which is pressurized and cooled to a predetermined pressure and temperature; (b) providing an absorption column and a supply of substantially pure liquid carbon dioxide absorbent at substantially said predetermined pressure and temperature; (c) introducing absorbent from said supply thereof and feed gas stream into said absorption column for separating of said hydrogen sulfide and carbonyl sulfide from said lower boiling point gas; (d) contacting said feed gas stream in said absorption column with a countercurrent flow of absorbent in an amount sufficient, but not exceeding that required, to absorb and entrain substantially all of said hydrogen sulfide present in the gas stream and thereby also to absorb and entrain substantially all of said carbonyl sulfide in the gas stream while maintaining most of the absorbent in the liquid state at substantially said pressure and temperature, the balance of the absorbent being vaporized by the heat of condensation of the absorbed gas; (e) withdrawing from said absorption column a substantially completely desulfurized residual gas stream containing said relatively lower boiling point gas and a mixture of the still liquid absorbent and gases absorbed or entrained therewith; and (f) recovering substantially pure carbon dioxide from said desulfurized residual gas stream to concentrate further said relatively lower boiling point gas.
Claim 31
Dependent Claim
259 words
A process for treating a feed gas stream comprising relatively high boiling point gases including hydrogen sulfide, carbonyl sulfide, and carbon dioxide and relatively lower boiling point gas of primary value, comprising precluding the need to distill the feed gas stream by the steps of: (a) providing a feed gas stream which is pressurized and cooled to a predetermined pressure and temperature; (b) providing an absorption column and a supply of substantially pure liquid carbon dioxide absorbent at substantially said predetermined pressure and temperature; (c) introducing absorbent from said supply thereof and feed gas stream into said absorption column for separating of said hydrogen sulfide and carbonyl sulfide from said lower boiling point gas; (d) contacting said feed gas stream in said absorption column with a countercurrent flow of absorbent in an amount sufficient, but not exceeding that required, to absorb and entrain substantially all of said hydrogen sulfide present in the gas stream and thereby also to absorb and entrain substantially all of said carbonyl sulfide in the gas stream while maintaining most of the absorbent in the liquid state at substantially said pressure and temperature, the balance of the absorbent being vaporized by the heat of condensation of the absorbed gas; (e) withdrawing from said absorption column a substantially completely desulfurized residual gas stream containing said relatively lower boiling point gas and a mixture of the still liquid absorbent and gases absorbed or entrained therewith; and (f) recovering substantially pure carbon dioxide from said desulfurized residual gas stream to concentrate further said relatively lower boiling point gas.
Claim 32
Dependent Claim
30 words
A process according to claim 26, in which at least a portion of the recovered carbon dioxide of step (f) is returned to said absorption column for reuse as absorbent.
Claim 33
Dependent Claim
52 words
A process according to claim 26, in which both the feed gas stream and liquid carbon dioxide absorbent are brought into contact in step (d) at substantially the same temperature and pressure and said temperature is substantially the dew point temperature of carbon dioxide in the feed gas stream at that pressure.
Claim 34
Dependent Claim
51 words
A process according to claim 26, in which the substantially completely desulfurized residual gas stream withdrawn from said absorption column in step (e) is cooled to condense carbon dioxide therefrom and the so-condenzed carbon dioxide reflux is returned to the process and used as part of the absorbent in step (d).
Claim 35
Dependent Claim
47 words
A process according to claim 26, in which step (d) is performed by withdrawing the substantially completely desulfurized residual gas stream from the top of said absorption column and the mixture of still liquid absorbent and gases absorbed or entrained therewith from the bottom of the column.
Claim 36
Dependent Claim
71 words
A process according to claim 26, in which the mixture of still liquid absorbent and gases absorbed or entrained therewith withdrawn from said absorption column in step (e) is processed to recover carbon dioxide therefrom and leave a mixture enriched in sulfur-containing gas, and carbon dioxide separated from said mixture is used in step (f) as a refrigerant for cooling the substantially completely desulfurized residual gas stream and recovering carbon dioxide.
Claim 37
Dependent Claim
23 words
A process according to claim 31, in which additional carbon dioxide separated from said mixture is also used as absorbent in step (d).
Claim 38
Dependent Claim
23 words
A process according to claim 26, in which said relatively lower boiling point gas comprises a major portion of said feed gas stream.
Claim 39
Dependent Claim
52 words
A process according to claim 26, in which said feed gas stream includes at least one additional gas of relatively lower boiling point selected from the group consisting of hydrogen, carbon monoxide, nitrogen, and methane, and said relatively lower boiling point gases comprise a major and portion of said feed gas stream.
Claim 40
Dependent Claim
31 words
A process according to claim 26, in which said feed gas stream consists essentially of hydrogen, carbon monoxide, nitrogen, and methane, together with said hydrogen sulfide, carbonyl sulfide, and carbon dioxide.
Claim 41
Dependent Claim
20 words
A process according to claim 26, in which step (a) includes cooling said feed gas stream to said predetermined temperature.
Claim 42
Dependent Claim
249 words
A process for treating a feed gas stream comprising relatively high boiling point gases including carbonyl sulfide and a relatively lower boiling point gas of primary value, comprising precluding the need to distill the feed gas stream by the steps of: (a) providing a feed gas stream which is pressurized and cooled to a predetermined pressure and temperature; (b) providing an absorption column and a supply of substantially pure liquid carbon dioxide absorbent at substantially said predetermined pressure and temperature; (c) determining an effective flow range of absorbent equal to from about 70% to about 140% of the flow which would be required to absorb and entrain substantially all hydrogen sulfide in an otherwise indentical feed gas stream except for the substitution of hydrogen sulfide for carbonyl sulfide; (d) introducing absorbent from said supply thereof and said feed gas stream into said absorber for separation of said carbonyl sulfide from the gas stream; (e) countercurrently contacting said feed gas stream in said absorber with absorbent at a flow within said effective flow range to absorb and entrain substantially all carbonyl sulfide in the feed gas stream while maintaining most of the absorbent in the liquid state at substantially said pressure and temperature, the balance of the absorbent being vaporized by the heat of condensation; and (f) withdrawing from said absorption column a substantially completely desulfurized residual gas stream containing said relatively lower boilding point gas and a mixture of the still liquid absorbent and gases absorbed or entrained therewith.
Claim 43
Dependent Claim
249 words
A process for treating a feed gas stream comprising relatively high boiling point gases including carbonyl sulfide and a relatively lower boiling point gas of primary value, comprising precluding the need to distill the feed gas stream by the steps of: (a) providing a feed gas stream which is pressurized and cooled to a predetermined pressure and temperature; (b) providing an absorption column and a supply of substantially pure liquid carbon dioxide absorbent at substantially said predetermined pressure and temperature; (c) determining an effective flow range of absorbent equal to from about 70% to about 140% of the flow which would be required to absorb and entrain substantially all hydrogen sulfide in an otherwise indentical feed gas stream except for the substitution of hydrogen sulfide for carbonyl sulfide; (d) introducing absorbent from said supply thereof and said feed gas stream into said absorber for separation of said carbonyl sulfide from the gas stream; (e) countercurrently contacting said feed gas stream in said absorber with absorbent at a flow within said effective flow range to absorb and entrain substantially all carbonyl sulfide in the feed gas stream while maintaining most of the absorbent in the liquid state at substantially said pressure and temperature, the balance of the absorbent being vaporized by the heat of condensation; and (f) withdrawing from said absorption column a substantially completely desulfurized residual gas stream containing said relatively lower boilding point gas and a mixture of the still liquid absorbent and gases absorbed or entrained therewith.
Claim 44
Dependent Claim
36 words
A process as set forth in claim 37, wherein said effective flow range determined in step (c) is equal to from about 70% to about 120% of that needed to absorb and entrain all hydrogen sulfide.
Claim 45
Dependent Claim
23 words
A process according to claim 37, in which said relatively lower boiling point gas comprises a major portion of said feed gas stream.
Claim 46
Dependent Claim
51 words
A process according to claim 37, in which said feed gas stream includes at least one additional gas of relatively lower boiling point selected from the group consisting of hydrogen, carbon monoxide, nitrogen, and methane, and said relatively lower boiling point gases comprise a major portion of said feed gas stream.
Claim 47
Dependent Claim
49 words
A process as set forth in claim 37, wherein said feed gas stream also includes hydrogen sulfide, and said effective flow range determined in step (c) is equal to from about that needed to absorb and entrain substantially all of the hydrogen sulfide to about 140% of that flow.
Claim 48
Dependent Claim
49 words
A process as set forth in claim 37, wherein said feed gas stream also includes hydrogen sulfide, and said effective flow range determined in step (c) is equal to from about that needed to absorb and entrain substantially all of the hydrogen sulfide to about 120% of that flow.
Claim 49
Dependent Claim
23 words
A process according to claim 42, in which said relatively lower boiling point gas comprises a major portion of said feed gas stream.
Claim 50
Dependent Claim
51 words
A process according to claim 42, in which said feed gas stream includes at least one additional gas of relatively lower boiling point selected from the group consisting of hydrogen, carbon monoxide, nitrogen, and methane, and said relatively lower boiling point gases comprise a major portion of said feed gas stream.
References Cited (Backward Citations)
US3417572A
Cited
US3643451A
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| 11.5 Years (Year 12) | 1997-09-01 | 1998-03-03 | 1998-09-02 | $7700.00 | Window Closed / Lapsed |