WO2015004130A1 - Procédé pour l'élimination de contaminants acides d'un courant de gaz - Google Patents

Procédé pour l'élimination de contaminants acides d'un courant de gaz Download PDF

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Publication number
WO2015004130A1
WO2015004130A1 PCT/EP2014/064598 EP2014064598W WO2015004130A1 WO 2015004130 A1 WO2015004130 A1 WO 2015004130A1 EP 2014064598 W EP2014064598 W EP 2014064598W WO 2015004130 A1 WO2015004130 A1 WO 2015004130A1
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WO
WIPO (PCT)
Prior art keywords
acidic contaminants
liquid phase
enriched
phase
mixture
Prior art date
Application number
PCT/EP2014/064598
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English (en)
Inventor
Thijme Last
Armin Schneider
Renze Wijntje
Original Assignee
Shell Internationale Research Maatschappij B.V.
Shell Oil Company
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Filing date
Publication date
Application filed by Shell Internationale Research Maatschappij B.V., Shell Oil Company filed Critical Shell Internationale Research Maatschappij B.V.
Publication of WO2015004130A1 publication Critical patent/WO2015004130A1/fr

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    • 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
    • B01D53/14—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 absorption
    • B01D53/1456—Removing acid 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
    • B01D53/14—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 absorption
    • B01D53/1425—Regeneration of liquid absorbents
    • 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
    • B01D53/14—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 absorption
    • B01D53/18—Absorbing units; Liquid distributors therefor
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
    • C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
    • C10L3/10—Working-up natural gas or synthetic natural gas
    • C10L3/101—Removal of contaminants
    • C10L3/102—Removal of contaminants of acid contaminants
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2252/00—Absorbents, i.e. solvents and liquid materials for gas absorption
    • B01D2252/20—Organic absorbents
    • B01D2252/204—Amines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2252/00—Absorbents, i.e. solvents and liquid materials for gas absorption
    • B01D2252/60—Additives
    • B01D2252/602—Activators, promoting agents, catalytic agents or enzymes
    • 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
    • B01D2256/24—Hydrocarbons
    • 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
    • B01D2257/304—Hydrogen sulfide
    • 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
    • B01D2257/306—Organic sulfur compounds, e.g. mercaptans
    • 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
    • B01D2257/308—Carbonoxysulfide COS
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/50—Carbon oxides
    • B01D2257/504—Carbon dioxide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/06—Polluted air
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L2290/00—Fuel preparation or upgrading, processes or apparatus therefore, comprising specific process steps or apparatus units
    • C10L2290/06—Heat exchange, direct or indirect
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L2290/00—Fuel preparation or upgrading, processes or apparatus therefore, comprising specific process steps or apparatus units
    • C10L2290/12—Regeneration of a solvent, catalyst, adsorbent or any other component used to treat or prepare a fuel
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L2290/00—Fuel preparation or upgrading, processes or apparatus therefore, comprising specific process steps or apparatus units
    • C10L2290/54—Specific separation steps for separating fractions, components or impurities during preparation or upgrading of a fuel
    • C10L2290/541—Absorption of impurities during preparation or upgrading of a fuel

Definitions

  • the present invention relates to a process for removing acidic contaminants from a gas stream, in particular a natural gas stream.
  • the methods may be based on physical and/or chemical separation techniques. Physical separation techniques use
  • fractionating column or differences in density to separate contaminants with different densities by gravity
  • Chemical separation techniques may employ selective absorption or catalytic reactions to convert an acidic contaminant into a composition that can be easily separated.
  • an absorbent component typically an amine-containing absorbent solution
  • absorbent stream are obtained.
  • the acidic contaminants- depleted stream may be further subjected to further processing steps, if desired, before being sent to its intended end-use.
  • the acidic contaminants-enriched absorbent stream is typically regenerated in order to be able to reuse the absorbent, and the acidic contaminants- enriched gas stream obtained during the regenerating step typically is removed from the upper part of the
  • regenerator vessel applied.
  • the acidic contaminants- enriched gas stream obtained is then cooled at least part of the cooled gas stream is recycled to the regenerator.
  • DIPA diisopropylamine
  • DEA diethanolamine
  • DGA diglycolamine
  • absorbent component is included in the acidic
  • Object of the present invention is to provide an improved process for removing acidic contaminants from a gas stream, wherein more effectively use is made of the absorbent component.
  • the present invention relates to a process for removing acidic contaminants from a gas stream comprising the steps of:
  • step (b) subjecting at least part of the acidic contaminants- enriched absorbent solution as obtained in step (a) to conditions that allow the formation of a multi-phase mixture which comprises an acidic contaminants-enriched gaseous phase, an acidic contaminants-depleted liquid phase and an acidic contaminants-enriched liquid phase;
  • step (c) subjecting at least part of the multi-phase mixture as obtained in step (b) to a regeneration treatment in a regenerator vessel to obtain an acidic contaminants- enriched gas stream, an acidic contaminants-depleted liquid phase and an acidic contaminants-enriched liquid phase ;
  • step (d) cooling at least part of the acidic contaminants- enriched gas stream as obtained in step (c) to obtain a cooled mixture comprising an acidic contaminants-enriched gaseous phase and a condensate liquid phase;
  • step (e) introducing the cooled mixture as obtained in step (d) into a separator vessel to separate the cooled mixture into an acidic contaminants-enriched gaseous phase and a condensate liquid phase;
  • step (f) withdrawing from the separator vessel condensate liquid phase as obtained in step (e) ;
  • (g) recycling at least part of the condensate liquid phase as withdrawn in step (f) to step (c) ;
  • step (h) introducing at least part of the condensate liquid phase as withdrawn in step (f) into the separator vessel used in step (e) above the point at which the cooled mixture is introduced into the separator vessel in step (e) .
  • the present process has the major advantage that it allows for a considerable improvement in the effective use of the absorbent solution.
  • step (b) the multi ⁇ phase mixture as obtained in step (b) is subjected to a regeneration treatment in step (c) , during which
  • the multi-phase mixture is separated into an acidic contaminants-enriched gaseous phase, an acidic contaminants-depleted liquid phase and an acidic contaminants-enriched liquid phase by
  • contacting the multi-phase mixture with a high surface area internal which comprises a material that is less hydrophilic as compared to metal which is arranged within the regenerator vessel.
  • This preferred embodiment has as further advantages that it allows for reduced entrainment of the acid contaminant-depleted phase, a considerable decrease in processing time, whereas at the same time processing space can be reduced significantly because no large separating drums are required before or after the
  • regenerator vessel thereby also reducing the required absorbent inventory of the system.
  • mass transfer barriers between the acid contaminant-enriched fraction and the stripping gas are now minimised, and also differences in liquid fraction hold-up and residence time are minimised, thereby facilitating more
  • step (a) a gas stream which contains acidic contaminants is contacted with an absorbent solution that absorbs acidic contaminants to obtain an acidic
  • the acidic contaminants-containing gas stream is not limited in any way (in terms of composition, phase, etc.) and may for example be a natural gas stream, a combustion gas, synthesis gas, an air stream, etc.; the contaminated stream may also be a contaminated liquid hydrocarbon stream such as a contaminated LPG stream.
  • the acidic contaminants-containing gas stream is a methane- rich stream such as natural gas, containing at least 30 wt . % methane, preferably at least 50 wt . % methane.
  • the acidic contaminants may include acidic contaminants such as carbon dioxide (C0 2 ) , hydrogen sulphide (3 ⁇ 4S) , carbonyl sulphide (COS) and mercaptans such as
  • the present invention is in particular suitable for the removal of CO 2 and/or 3 ⁇ 4S from a contaminated gas stream such as natural gas stream or a combustion gas stream.
  • the acidic contaminants-containing gas stream is suitably contacted in an absorber with the absorbent solution, thereby obtaining the acidic contaminants- depleted gas stream and the acidic contaminants-enriched absorbent solution.
  • the acidic contaminants- depleted gas stream is obtained at the upper part of the absorber and subsequently removed.
  • the contaminants-depleted gas stream may be further processed if needed before it is sent to its end use.
  • the acidic contaminants-enriched absorbent solution is obtained at the lower part of the absorber.
  • the absorber is operated at a temperature in the range of from 10-100°C, more
  • the absorber is suitably operated at a pressure in the range of from 1.0-110 bara, more preferably at a pressure in the range of from 20-90 bara.
  • the absorbent solution in step (a) is an aqueous absorbent solution comprising water and an absorbent component.
  • the absorbent solution is preferably a single phase.
  • the absorbent solution may comprise two or more absorbent components.
  • the one or more absorbent components are not limited in any way. Usually, the one or more absorbent components are amine compounds. Suitable absorbent solutions have been
  • the absorbent solution in step (a) is an aqueous amine-containing absorbent solution.
  • the amine is selected from the group consisting of tertiary alkylamines, tertiary alkoxyamines , tertiary polyamines, secondary alkylamines, secondary alkoxyamines substituted with alkyl groups, polyamines containing tertiary and secondary and/or primary amine groups and tertiary alkanolamines
  • a component acting as accelerator such as but not limited to piperazine and derivatives, monoethanolamine, piperidine and derivatives and
  • step (b) at least part of the acidic
  • contaminants-enriched absorbent solution as obtained in step (a) is subjected to conditions that allow the formation of a multi-phase mixture which comprises an acidic contaminants-enriched gaseous phase, an acidic contaminants-depleted liquid phase and an acidic
  • Suitable conditions to establish this include acidic conditions, raising the temperature and/or decreasing the pressure of the acidic contaminants-enriched absorbent solution.
  • Acidic conditions can be established by adding one or more acids to the acidic contaminants-enriched absorbent solution.
  • Suitable acids include for example oxalic acid, phosphoric acid, pyrophosphoric acid, phosphorous acid, hypochlorous acid, hydrochloric acid, nitrous acid, nitric acid, acetic acid, formic acid, propanoic acid, butanoic acid, sulphurous acid, sulphuric acid, amino- acids and any mixture thereof.
  • the pressure of the acidic contaminants- enriched absorbent solution as obtained in step (a) is in de range of from 20-110 bara.
  • the pressure of the acidic contaminants-enriched absorbent solution can be decreased to a level that is in the range of the total acid gas component (s) pressure in the feed gas or lower.
  • the pressure of the acidic contaminants-enriched absorbent solution may be in the range of from 0.001-50 bara, preferably of from 1-30 bara, more preferably 1.0-8 bara.
  • the temperature of the acidic contaminants- enriched absorbent solution as obtained in step (a) is in de range of from 50-100°C.
  • the temperature of the acidic contaminants-enriched absorbent solution can be increased by 5-130°C, preferably by 20-
  • step (b) the temperature of the acidic
  • contaminants-enriched absorbent solution may be in the range of from 60- 170°C, more preferably at a temperature in the range of from 70-160°C, even more preferably at a temperature in the range of from 100-140°C.
  • the acidic contaminants-depleted liquid phase is a water-depleted liquid phase and is relatively absorbent (typically amine) rich, and the first acidic
  • contaminants-enriched liquid phase is a water-enriched liquid phase and is relatively absorbent (typically) amine poor.
  • step (b) can be carried out before step (c) .
  • at least part of the multi-phase mixture is obtained before the regeneration treatment and at least part of the multi-phase mixture so obtained is subjected to the regeneration treatment in step (c) .
  • at least part of step (b) can be carried out in a flashing vessel in which the acidic contaminants- enriched absorbent solution as obtained in step (a) is introduced after which the multi-phase mixture so
  • step (b) can also suitably be carried out before the acidic contaminants-enriched absorbent solution is introduced into the flashing vessel.
  • at least part of step (b) can be carried out in a heat exchanger which may be arranged upstream the regenerator in which step (c) will be carried out.
  • at least part of step (b) may be carried out when the acidic contaminants-enriched absorbent solution is introduced in the upper part of the regenerator vessel in which step (c) is carried out.
  • step (b) may take place at different stages of the present process.
  • Step (b) can be carried out partly before step (c) and partly during step (c) .
  • step (b) will be carried during step (c) .
  • this will mean that at least part of step (b) will take place in an upper part of the regenerator vessel in which step (c) will be carried out.
  • most of step (b) will be carried out during step (c) .
  • step (c) at least part of the multi-phase mixture as obtained in step (b) is subjected to a regeneration treatment .
  • Step (c) is typically carried out in a regenerator vessel .
  • the multi-phase mixture as obtained in step (b) is introduced in an upper part of the
  • regenerator vessel to be used in step (c) .
  • the regeneration treatment in step (c) can be carried out using one or more flash vessels, a column or a combination thereof.
  • the acidic contaminants-enriched gas stream will be obtained at the upper part of the regenerator vessel and the acidic contaminants-depleted liquid phase and the acidic contaminants-enriched liquid phase will be obtained.
  • step (c) At least part of the acidic contaminants-depleted liquid phase as obtained in step (c) and/or at least part of the acidic contaminants-enriched liquid phase as obtained in step (c) is (are) recycled to step (a) .
  • (c) is carried out at a temperature sufficiently high to ensure that a substantial amount of the acidic
  • step (c) is carried out at a temperature in the range of from 60-
  • step (c) is carried out at a pressure in the range of from 0.001-50 bara, more preferably at a pressure in the range of from from 1.0-30 bara, and even more preferably at a pressure in the range of from 1.0-8 bara.
  • the acidic contaminants-depleted liquid phase is a water-depleted liquid phase and is relatively absorbent component (typically amine) rich, and the acidic
  • contaminants-enriched liquid phase is a water-enriched liquid phase and is relatively absorbent component
  • the acidic contaminants-enriched gas stream is recovered from the upper part of the regenerator vessel.
  • the acidic contaminants-depleted liquid phase and the acidic contaminants-enriched liquid phase are
  • lower part refers to a place in the regeneration vessel where liquid accumulates; the bottom part is (although preferably it is) not necessarily the absolute bottom of the
  • regenerator vessel but may also be a local bottom part such as a draw-off tray.
  • Step (c) can suitably be carried out in one or more regenerator vessels. If step (c) is carried out in one regenerator vessel (which it preferably does from the viewpoint of simplicity) , the acidic contaminants- enriched liquid phase is typically obtained at the
  • step (c) in addition to the acidic contaminants- enriched liquid phase an acidic contaminants-depleted liquid phase is formed under the prevailing conditions in the regenerator vessel which can also be recovered from the bottom part of the regenerator vessel.
  • the acidic contaminants-depleted liquid phase and the acidic contaminants-enriched liquid phase can be any organic contaminants-depleted liquid phase and the acidic contaminants-enriched liquid phase.
  • the two liquid phases are suitably removed in the same ratio as they are formed, ensuring that the absorbent content of the removed stream remains substantially constant over time.
  • at least part of the acidic contaminants- enriched liquid phase is removed from the regenerator vessel, heated and reintroduced into the regenerator vessel at a point above the interface of the acidic contaminants-depleted liquid phase and the acidic contaminants-enriched liquid phase.
  • At least part of the acidic contaminants- enriched liquid phase as obtained in step (c) may be reused at several other process stages but is preferably at least partly reused in step (a) as the absorber solution .
  • the acidic contaminants-enriched liquid phase as obtained in step (c) is cooled before it is reused at another stage in the present process, hereby obtaining a cooled acidic-contaminants-enriched liquid phase.
  • the cooled acidic- contaminants-enriched liquid phase is passed to a collector before it is reused in another stage of the process, particular if said liquid phase is to be reused in the absorber and combined with the acidic
  • the collector will be a simple vessel.
  • step (b) At least a part of the multi-phase mixture as obtained in step (b) is subjected to a regeneration treatment in step (c) , during which regeneration treatment the multi-phase mixture is separated into an acidic contaminants-enriched gaseous phase, an acidic contaminants-depleted liquid phase and an acidic contaminants-enriched liquid phase by contacting the multi-phase mixture with a high surface area internal which comprises a material that is less hydrophilic as compared to metal and which is arranged within the regenerator vessel.
  • the high surface area internal that may be used in step (c) comprises a material that is less hydrophilic as compared to metal.
  • the high surface area internal that may be used in step (c) comprises at least 50 wt%, more preferably at least 70 wt ⁇ 6 , even more preferably at least 90 wt% of a material that is less hydrophilic as compared to metal, calculated on the total weight of the high surface area internal.
  • the material that is less hydrophilic as compared to metal preferably is less hydrophilic as compared to carbon steel, austenitic stainless steel, duplex
  • stainless steel hastelloy, aluminium-brass, aluminium- bronze alloys or titanium, more preferably less
  • hydrophilic as compared to austenitic stainless steel or duplex stainless steel.
  • the material that is less hydrophilic as compared to metal may be or may comprise carbon, a polymer, a carbon fiber polymer composite, and/or a ceramic material.
  • the material that is less hydrophilic as compared to metal is or comprises carbon.
  • the polymer in the composite may be a
  • thermoplastic polymer or a mixture of thermoplastic polymers, or a thermosetting polymer or a mixture of thermosetting polymers.
  • the polymer in the composite is chlorinated polyvinyl
  • CPVC polyvinylidene difluoride
  • PVDF polyvinylidene difluoride
  • PEEK polyether ether ketone
  • PTFE polytetrafluoroethylene
  • PSU polysulphone
  • the polymer in the composite is polyester resin, epoxy resin, melamine resin, polyimide,
  • polyurethane or a mixture thereof.
  • the material that is less hydrophilic as compared to metal is or comprises a thermoplastic polymer or a mixture of thermoplastic polymers, or a thermosetting polymer or a mixture of thermosetting polymers.
  • the polymer is or comprises chlorinated polyvinyl chloride
  • CPVC polyvinylidene difluoride
  • PVDF polyvinylidene difluoride
  • PEEK polyether ether ketone
  • polytetrafluoroethylene PTFE
  • PSU polysulphone
  • the polymer is or comprises polyester resin, epoxy resin, melamine resin, polyimide, polyurethane, or a mixture thereof.
  • the material that is less hydrophilic as compared to metal is or comprises a ceramic material.
  • the high surface area internal which comprises a material that is less hydrophilic as compared to metal has a surface in the range of from 50-1500 m 2 /m 3 , preferably in the range of from 100-1500 m 2 /m 3 , and more preferably in the range of from 200-1500 m 2 /m 3 .
  • the high surface area internal which comprises a material that is less hydrophilic as compared to metal which is arranged within the regenerator vessel is a packing.
  • the packing is a structured packing.
  • Structured packings typically consist of gauzes or thin corrugated plates arranged in such a way that they allow gas or liquid streams to take particular paths through the regenerator vessel. In this way a large surface area is established for contact with the various different phases in the regenerator vessel.
  • the structured packing to be used in accordance with the present invention is formed from corrugated sheets of perforated polymer or wire gauze, thereby forming an open honeycomb structure.
  • At least one section of the packing is arranged in the upper part of the regenerator vessel.
  • the high surface area internal may also be a random packing or the high surface area internal may be in the form of the internals used in a fiber-film
  • An advantage of using high surface area internals which comprise a material that is less hydrophilic as compared to metal, instead of metal high surface area internals, is that it results in an improved phase separation inside the regenerator vessel.
  • the acidic contaminants- enriched fraction When in the regenerator vessel metal high surface area internals would be used, the acidic contaminants- enriched fraction would wet the packing, while the acidic contaminants-depleted fraction would form a layer between the stripping gas phase in the regenerator vessel and the acidic contaminants-enriched fraction, thereby reducing effectiveness of the regeneration process by providing an additional mass transfer barrier and enhancing
  • the acid contaminant- enriched fraction would primarily fill the bottom part of the tray volume over time, with a thin layer of acid contaminant-depleted fraction or multiphase liquid on the top part of the tray. While such a setup would remove the additional mass transfer barrier as would be experienced with a metal high surface area packing, a person skilled in the art would understand that it results in large differences in residence time of both fractions in the regenerator vessel, resulting in different liquid hold ⁇ ups and thereby introducing significant challenges to the start-up of the process system, as both fractions will have different overall circulating times through the absorber, as a single phase, and the regenerator vessel.
  • the acid contaminant-depleted fraction that is present on the trays in the regenerator vessel as a thin layer above the acid contaminant-enriched fraction will also experience enhanced entrainment in comparison to the acid contaminant-depleted fraction. Since the acid contaminant-depleted fraction is typically enriched in the active absorbent, such as an amine, the relative enhanced entrainment of the acid contaminant-depleted fraction results in enhanced losses of active absorbing component .
  • step (c) use is made in step (c) of at least a first high surface area internal which comprises a material that is less hydrophilic as compared to metal and a second high surface area internal which comprises a material that is less hydrophilic as compared to metal, wherein the first high surface area internal is arranged above the point where at least part of the acidic contaminants-enriched absorbent solution as obtained in step (a) and/or at least part of the multi-phase mixture as obtained in step (b) is introduced into the regenerator vessel, and wherein the second high surface area internal is arranged below the point where at least part of the acidic
  • step (d) at least part of the acidic- contaminants-enriched gas stream as obtained in step (c) is cooled to obtain a cooled mixture comprising an acidic contaminants-enriched gaseous phase and a condensate liquid phase.
  • the cooling in step (d) is carried out at a pressure in the range of from 0.001-50 bara, more
  • the cooled mixture as obtained in step (d) has suitably a temperature in the range of from 20-70 °C, preferably at a temperature in the range of from 30-60 °C, and more preferably at a temperature in the range of from 30-50 °C.
  • step (e) the cooled mixture as obtained in step (d) is introduced into a separator vessel to separate the cooled mixture into an acidic contaminants-enriched gaseous phase and a condensate liquid phase.
  • Step (e) is suitably carried out at a temperature in the range of from 20-70 °C, preferably at a temperature in the range of from 30-60 °C, and more preferably at a temperature in the range of from 30-50 °C.
  • Step (e) is suitably carried out during a period of time in the range of from 20 seconds to 10 minutes, preferably Step (e) is suitably be carried out during a period of time in the range of from 2 to 5 minutes.
  • step (f) condensate liquid phase as obtained in step (e) is withdrawn from the separator vessel.
  • the condensate liquid phase is withdrawn from a lower part of the separator vessel.
  • step (g) at least part of the condensate liquid phase as withdrawn in step (f) is recycled to step (c) .
  • step (f) At least 5 % by volume of the condensate liquid phase as withdrawn in step (f) is recycled to step (c) . More preferably, at least 10 % by volume of the condensate liquid phase as withdrawn in step (f) is recycled to step (c) , even more preferably the volume of the condensate liquid phase as withdrawn in step (f) that is recycled to step (c) is equal or close to the volume of condensate liquid phase produced in step (d) .
  • step (g) the condensate liquid phase is recycled to the regenerator vessel above the point at which the acidic contaminants-enriched absorbent solution as obtained in step (a) and/or the multi-phase mixture as obtained in step (b) is (are) introduced into the regenerator vessel.
  • step (h) at least part of the condensate liquid phase as withdrawn in step (f) is introduced into the separator vessel used in step (e) above the point at which the cooled mixture is introduced into the separator vessel in step (e) .
  • step (h) at least 10 % by volume of the condensate liquid phase as withdrawn in step (f) is introduced into the separator vessel used in step (e) .
  • step (e) More preferably, at least 50 % by volume of the condensate liquid phase as withdrawn in step (f) is introduced into the separator vessel used in step (e) .
  • step (h) the condensate liquid phase is introduced above the point at which the cooled mixture is introduced into the separator vessel in step (e) .
  • the condensate liquid phase is introduced into the separator vessel above gas-liquid contact enhancing internals such as a high surface area internal or one or more trays to remove residual liquid droplets and absorbent component in the vapour phase from the acidic component-enriched gaseous phase.
  • gas-liquid contact enhancing internals such as a high surface area internal or one or more trays to remove residual liquid droplets and absorbent component in the vapour phase from the acidic component-enriched gaseous phase.
  • the separator vessel as used in step (e) contains a demisting device above the point where the condensate liquid phase is introduced in step (h) .
  • the high surface area internal which can be used in the separator vessel has a surface in the range of from 50-1500 m 2 /m 3 , preferably in the range of from 100-1500 m 2 /m 3 , and more preferably in the range of from 200-1500 m 2 /m 3 .
  • the high surface area internal which is arranged with the separator vessel is a packing.
  • the packing can be a metal or a non-metal packing.
  • the packing is a structured packing.
  • the packing is a non-metal packing
  • the packing can suitably be a carbon packing or a polymer packing.
  • the non-metal packing is a polymer packing.
  • the polymer may be a thermoplastic or a mixture of thermoplastics. Suitable examples of polymers to be used in accordance with the present invention include polypropylene (PP) , post chlorinated polyvinylchloride
  • the packing is a structured packing.
  • the packing is a structured polymer packing.
  • the packing is a metal packing
  • the metal from which the packing can be made is suitably chosen from the group consisting of carbon steels, stainless steels (austenitic and duplex) , hastelloy, aluminium- brass and aluminium-bronze alloys and titanium.
  • the metal is an austenitic stainless steel or duplex stainless steel. More preferably, the metal is austenitic stainless steel.
  • Structured packings typically consist of gauzes or thin corrugated metal or polymer plates arranged in such a way that they allow gas or liquid streams to take particular paths through the separator vessel. In this way a large surface area is established for contact with the various
  • the structured packing to be used in accordance with the present invention is formed from corrugated sheets of perforated embossed metal, polymer or wire gauze, thereby forming an open honeycomb
  • the high surface area internal may also be a random packing or the high surface area internal may be in the form of the internals used in a fibre-film
  • FIG. 1 shows a simplified embodiment of a process in accordance with the present invention for removing acidic contaminants from a gas stream.
  • an acidic contaminants-containing gas stream is introduced into the absorber 1 via a line 2, and contacted in absorber 1 with an absorbent solution which is introduced in absorber 1 via a line 3,
  • absorbent solution is then sent via pump 6 and line 7 to flashing vessel 8.
  • flashing vessel 8 a gas fraction is formed and a multi-phase mixture which comprises an acidic contaminants-enriched gaseous phase, an acidic contaminants-depleted liquid phase and an acidic
  • the gas fraction is withdrawn via line 9, whereas the multi-phase mixture is withdrawn via line 10 and passed to heat exchanger 11.
  • heat exchanger 11 the multi-phase mixture is heated and the heated multi-phase mixture is introduced into an upper part of the regenerator vessel 12 via line 13.
  • regeneration vessel 12 the multi-phase mixture is
  • the acidic contaminants-enriched gas stream is withdrawn from the regenerator vessel 12 via line 14 and passed to cooling unit 15.
  • the acidic contaminants- depleted liquid phase is withdrawn via line 16, and recycled to the absorber 1 via lines 18 and 19, heat exchangers 11 and 20, pump 21 and line 3.
  • At least part of the acidic contaminants-enriched liquid phase is withdrawn from regenerator vessel 12 via line 17 and passed to heat exchanger 11.
  • heat exchanger 11 the acidic contaminants-enriched and acidic contaminants- depleted liquid phases are cooled, and the cooled liquid phases so obtained are recycled to absorber 1 via line 19, heat exchanger 20, line 21, pump 22 and line 3.
  • Part of the acidic contaminants-enriched liquid phase is withdrawn via line 23 and passed to reboiler unit 24 in which the liquid phase is heated, after which it is recycled to a bottom part of regenerator vessel 12 via line 25.
  • cooling unit 15 the acidic contaminants-enriched gaseous phase is cooled to obtain a cooled mixture comprising an acidic contaminants-enriched gaseous phase and a condensate liquid phase.
  • the cooled mixture is introduced into separator vessel 26 via line 27 in which the cooled mixture is separated into an acidic
  • the acidic contaminants-enriched gaseous phase is withdrawn from separator vessel 26 via line 28 and the condensate liquid phase is withdrawn via line 29.
  • At least part of the condensate liquid phase is recycled to regenerator vessel 12 via line 30, and at least part of the condensate liquid phase is introduced via line 31 into separator vessel 25 above the point at which the cooled mixture is introduced into separator vessel 26 via line 27.
  • Figure 2 shows a simplified embodiment of a
  • an acidic contaminants-containing gas stream is introduced into the absorber 1 via a line 2, and contacted in absorber 1 with an absorbent solution which is introduced in absorber 1 via a line 3, thereby obtaining an acidic contaminants-depleted stream which is removed from the upper part of absorber 1 via a line 4 and an acidic contaminants-enriched absorbent solution which is removed from the lower part of absorber 1 via a line 5.
  • absorbent solution is then sent via pump 6 and line 7 to flashing vessel 8.
  • flashing vessel 8 a gas fraction is formed and a multi-phase mixture which comprises an acidic contaminants-enriched gaseous phase, an acidic contaminants-depleted liquid phase and an acidic
  • the gas fraction is withdrawn via line 9, whereas the multi-phase mixture is withdrawn via line 10 and passed to heat exchanger 11.
  • heat exchanger 11 the multi-phase mixture is heated and the heated multi-phase mixture is introduced into an upper part of the regenerator vessel 12 via line 13.
  • the acidic contaminants- enriched absorbent solution is subjected to a
  • regenerator vessel 12 a multi-phase mixture is formed comprising an acidic contaminants-enriched gaseous phase, an acidic contaminants-depleted liquid phase and an acidic contaminants-enriched liquid phase.
  • the multi ⁇ phase mixture is separated into an acidic contaminants- enriched gaseous phase, an acidic contaminants-depleted liquid phase and an acidic contaminants-enriched liquid phase by contacting the multi-phase mixture with a high surface area internal 32 which comprises a material that is less hydrophilic as compared to metal.
  • the acidic contaminants-enriched gas stream is withdrawn from the regenerator vessel 12 via line 14 and passed to cooling unit 15.
  • the acidic contaminants-depleted liquid phase is withdrawn via line 16, and recycled to the absorber 1 via lines 18 and 19, heat exchangers 11 and 20, pump 21 and line 3. At least part of the acidic contaminants-enriched liquid phase is withdrawn from regenerator vessel 12 via line 17 and passed to heat exchanger 11. In heat
  • cooling unit 15 the acidic contaminants-enriched gaseous phase is cooled to obtain a cooled mixture comprising an acidic contaminants-enriched gaseous phase and a condensate liquid phase.
  • the cooled mixture is introduced into separator vessel 26 via line 27 in which the cooled mixture is separated into an acidic
  • the acidic contaminants-enriched gaseous phase is withdrawn from separator vessel 26 via line 28 and the condensate liquid phase is withdrawn via line 29.
  • At least part of the condensate liquid phase is recycled to regenerator vessel 12 via line 30, and at least part of the condensate liquid phase is introduced via line 31 into separator vessel 25 above the point at which the cooled mixture is introduced into separator vessel 26 via line 27.
  • the present invention relates to a process for removing acidic contaminants from a gas stream comprising the steps of: (a) contacting the gas stream (introduced via a line 2) with an aqueous absorbent solution that absorbs acidic contaminants (introduced via a line 3) to obtain an acidic contaminants-enriched aqueous absorbent solution (removed via line 5) and an acidic contaminants-depleted gas stream (removed via line 4);
  • step (b) subjecting at least part of the acidic contaminants- enriched absorbent solution as obtained in step (a) (via line 5) to conditions that allow the formation of a multi-phase mixture which comprises an acidic
  • step (c) subjecting at least part of the multi-phase mixture as obtained in step (b) (and introduced via line 13) to a regeneration treatment in a regenerator vessel (12) to obtain an acidic contaminants-enriched gas stream
  • step (d) cooling (in cooling unit 15) at least part of the acidic contaminants-enriched gas stream as obtained in step (c) (via line 14) to obtain a cooled mixture
  • step (e) introducing the cooled mixture as obtained in step (d) (via line 27) into a separator vessel (26) to
  • step (f) withdrawing from the separator vessel (26) condensate liquid phase as obtained in step (e) (via line 29); (g) recycling (via line 30) at least part of the
  • step (h) introducing (via line 31) at least part of the condensate liquid phase as withdrawn in step (f) into the separator vessel (26) used in step (e) above the point at which the cooled mixture is introduced (via line 27) into the separator vessel (26) in step (e) .
  • a 50wt% 1- [Bis [3- (dimethylamino) propyl] amino] -2- propanol (lb2DMAPA2P) forms two liquid phases when heated to typical AGRU regenerator conditions.
  • a 50wt% 2- (Diisopropylamino) ethanol (2DIPAE) forms two liquid phases at ambient temperature.
  • a 50wt% N-Methylcyclohexylamine (MCA) forms two liquid phases when heated to typical AGRU regenerator conditions .
  • Formulations 1 and 3 separated into two liquid phases after heating overnight to 125°C, whereas formulation 2 already forms two liquid phases at ambient conditions.
  • the water content of each liquid phase measured after separation of the phases is listed in table 1.
  • a 0.1 ml syringe was used to deposit a droplet of each phase onto a small plate of the following material:
  • a high surface area internal which comprises a material that is less hydrophilic as compared to metal (e.g. PEEK and/or PFTE) in the regenerator will result in an improved wetting of the amine-rich, acid contaminant-depleted upper phase on the high surface internal, such that this liquid phase preferentially wets the surface area instead of the water-rich, acid
  • the acid contaminant-enriched phase preferentially wets the high surface internal, resulting in a less efficient contact between the stripping gas and the acid
  • contaminant-depleted phase can form a mass transfer barrier.
  • enhanced amine losses occur due to entrainment of the acid contaminant-depleted phase, which is amine rich.

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  • Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Gas Separation By Absorption (AREA)

Abstract

L'invention concerne un procédé pour l'élimination de contaminants acides d'un courant de gaz dans lequel (a) le courant de gaz est mis en contact (1) avec une solution d'absorbant aqueuse pour obtenir une solution d'absorbant aqueuse enrichie en contaminants acides (5) et un courant de gaz appauvri en contaminants acides (4); (b) la solution d'absorbant enrichie en contaminants acides est amenée à former un mélange à phases multiples qui comprend une phase gazeuse enrichie en contaminants acides, une phase liquide appauvrie en contaminants acides et une phase liquide enrichie en contaminants acides; (c) le mélange à phases multiples est soumis à un traitement de régénération (12) pour obtenir un courant de gaz enrichi en contaminants acides, une phase liquide appauvrie en contaminants acides et une phase liquide enrichie en contaminants acides; (d) le courant de gaz enrichi en contaminants acides est refroidi (15) pour obtenir un mélange refroidi comprenant une phase gazeuse enrichie en contaminants acides et une phase liquide de condensat; (e) le mélange refroidi est séparé en une phase gazeuse enrichie en contaminants acides (28) et une phase liquide de condensat (29); (f) la phase liquide de condensat est soutirée; (g) une partie (30) de la phase liquide de condensat est recyclée dans l'étape (c); et (h) une partie (31) de la phase liquide de condensat est utilisée dans l'étape (e).
PCT/EP2014/064598 2013-07-10 2014-07-08 Procédé pour l'élimination de contaminants acides d'un courant de gaz WO2015004130A1 (fr)

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EP13175991 2013-07-10
EP13175993.8 2013-07-10
EP13175993 2013-07-10

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018044691A1 (fr) * 2016-08-30 2018-03-08 Fluor Technologies Corporation Refroidissement latéral variable pour élimination de gaz acide

Citations (3)

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Publication number Priority date Publication date Assignee Title
WO2009132661A1 (fr) * 2008-07-29 2009-11-05 Union Engineering A/S Procédé de récupération de dioxyde de carbone de grande pureté
EP2229996A1 (fr) * 2009-03-11 2010-09-22 General Electric Company Systèmes, procédés et appareil pour capturer le CO2 en utilisant un solvant
WO2011095703A1 (fr) * 2010-02-08 2011-08-11 IFP Energies Nouvelles Procede de desacidification d'un gaz par une solution absorbante avec liberation d'un effluent gazeux a partir de la solution absorbante et lavage de cet effluent par la solution absorbante regeneree

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Publication number Priority date Publication date Assignee Title
WO2009132661A1 (fr) * 2008-07-29 2009-11-05 Union Engineering A/S Procédé de récupération de dioxyde de carbone de grande pureté
EP2229996A1 (fr) * 2009-03-11 2010-09-22 General Electric Company Systèmes, procédés et appareil pour capturer le CO2 en utilisant un solvant
WO2011095703A1 (fr) * 2010-02-08 2011-08-11 IFP Energies Nouvelles Procede de desacidification d'un gaz par une solution absorbante avec liberation d'un effluent gazeux a partir de la solution absorbante et lavage de cet effluent par la solution absorbante regeneree

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KRIEBEL M: "Ullmann's Encyclopedia of Industrial Chemistry, Absorption, 2. Design of Systems and Equipment", INTERNET CITATION, 15 October 2008 (2008-10-15), pages 73 - 90, XP002717624, Retrieved from the Internet <URL:http://onlinelibrary.wiley.com/doi/10.1002/14356007.m01_m02/abstract> [retrieved on 20131209] *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018044691A1 (fr) * 2016-08-30 2018-03-08 Fluor Technologies Corporation Refroidissement latéral variable pour élimination de gaz acide
US10589213B2 (en) 2016-08-30 2020-03-17 Fluor Technologies Corporation Variable side cooling for acid gas removal

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