WO2016005402A1 - Procédé de production d'un courant de gaz purifié par absorption à deux étages - Google Patents

Procédé de production d'un courant de gaz purifié par absorption à deux étages Download PDF

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Publication number
WO2016005402A1
WO2016005402A1 PCT/EP2015/065513 EP2015065513W WO2016005402A1 WO 2016005402 A1 WO2016005402 A1 WO 2016005402A1 EP 2015065513 W EP2015065513 W EP 2015065513W WO 2016005402 A1 WO2016005402 A1 WO 2016005402A1
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WIPO (PCT)
Prior art keywords
liquid absorbent
gas
feed gas
loaded liquid
sour feed
Prior art date
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PCT/EP2015/065513
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English (en)
Inventor
Raimo Edwin Gregor Poorte
Renze Wijntje
Original Assignee
Shell Internationale Research Maatschappij B.V.
Shell Oil Company
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Publication of WO2016005402A1 publication Critical patent/WO2016005402A1/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
    • B01D53/1406—Multiple stage absorption
    • 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
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B17/00—Sulfur; Compounds thereof
    • C01B17/02—Preparation of sulfur; Purification
    • C01B17/04—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides
    • 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
    • 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
    • C10L3/103—Sulfur containing contaminants
    • 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
    • C10L3/104—Carbon dioxide
    • 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
    • B01D2256/245—Methane
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/30—Sulfur compounds
    • B01D2257/302—Sulfur oxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/30—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
    • B01D2258/05—Biogas
    • 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
    • B01D53/1456—Removing acid components
    • B01D53/1462—Removing mixtures of hydrogen sulfide and carbon dioxide
    • 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

Definitions

  • the invention relates to a process for producing a purified gas from a sour feed gas comprising carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide.
  • Gas streams such as from natural gas wells typically comprise contaminants such as carbon dioxide, hydrogen sulphide, mercaptans, carbonyl sulphide and carbon
  • Processes for removing sulphur- comprising contaminants and carbon dioxide from so-called "sour gas", i.e. a gas stream contaminated with acid gass such as hydrogen sulphide (H 2 S) , carbon dioxide (CO 2 ) and sulphur dioxide (SO 2 ) , are well known in the art.
  • Such processes typically comprise an absorption step for removing hydrogen sulphide and other sulphur compounds and/or carbon dioxide from the gaseous feed stream by contacting such gaseous feed stream with a solvent, for example an amine solvent, in an absorption column.
  • a purified gaseous stream often referred to as 'sweet gas' is obtained and a solvent loaded with contaminants.
  • the loaded solvent is typically regenerated in a stripper to obtain lean solvent that is recycled to the absorption column .
  • Example of circumstances requiring a high absorption capacity are high volumes of sour gas and/or high concentrations of acid gases such as carbon dioxide, hydrogen sulphide or sulphur dioxide in the sour gas feed stream.
  • Examples of circumstances requiring a capacity increase comprise an increase of the acid gas concentration in the sour feed gas, an increased supply of sour gas or a decrease in feed gas pressure (resulting in an increased feed gas volume) .
  • the capacity of a single absorption column is limited, so that an additional absorption column may be needed if capacity needs to be increased .
  • pre-contactor in the form of a static mixer or jet educator mixer in the sour gas feed stream to an absorber for bulk removal of acid gas in order to increase plant capacity with low capital expenditure.
  • the sour feed gas is contacted with lean amine.
  • a separator is placed downstream of the pre-contactor to separate rich amine from the pre-treated sour gas.
  • the pre-treated sour gas is supplied to a conventional counter-current
  • the bottom of the absorption column may be used as a separator provided the gas/liquid feed into the bottom of the column does not cause a problem with the inlet vapour distributor.
  • the rich amine is regenerated in a regenerator, together with rich amine from the absorption column.
  • absorption tower in the pre-contactor and by separating the bulk of the absorbent from the pretreated gas prior to subjecting the pre-treated gas to further acid gas removal in the counter-current absorber.
  • the invention relates to a process for producing a purified gas from a sour feed gas comprising carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide, the process comprising the following steps:
  • step (b) separating the further loaded liquid absorbent from the mixture obtained in step (a) to obtain pre- treated sour feed gas and a liquid stream of further loaded liquid absorbent;
  • step (c) contacting the pre-treated sour feed gas obtained in step (b) in an absorption column counter- currently with a liquid absorbent for absorbing carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide to obtain the purified gas and loaded liquid absorbent;
  • step (c) absorbent obtained in step (c) to step (a) , wherein the loaded liquid absorbent that is supplied to step (a) is cooled prior to being supplied to step (a) and/or during contacting with the sour feed gas in step (a) .
  • An important advantage of the process according to the invention is that use is made of the very efficient heat transfer conditions that exist in a co-current liquid-gas contactor. By cooling the loaded absorbent that is supplied to the pre-contactor either prior to or during the pre- contacting, use is made of these conditions and a large part of the exothermic heat produced in the absorption of acid gases can be efficiently cooled away. Thus, at any given temperature, a larger mole fraction of acid gas per volume absorbent can be loaded. Accordingly, the counter- current absorber can be operated at a relatively low
  • An advantage of the process according to the invention is that sour feed gas with high concentrations of acid gases, in particular carbon dioxide, can be purified using a single absorption column.
  • the process can be used for retrofitting such plant if an increased plant capacity is needed.
  • the process according to the invention can deal with large variations in feed gas volume or composition, in particular acid gas content, since the process can be operated by (partially) bypassing step (a) and dynamic variations in feed gas flow and/or acid gas concentration can be overcome without the need for adapting operation of the counter-current absorber.
  • Fig 2 Series of contactor/separation units.
  • a purified gas is produced from a sour feed gas that comprises carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide.
  • the feed gas may be any sour feed gas from which carbon dioxide and/or hydrogen sulphide need to be removed, optionally together with other compounds such as sulphur dioxide (SO 2 ) , carbonyl sulphide (COS) , carbon disulphide
  • CS 2 mercaptans
  • suitable sour feed gases include natural gas, refinery gases, associated gas, biogas, synthesis gas (syngas) or other industrial process gases.
  • the process is particularly suitable for sour feed gases that are available at elevated pressure.
  • the feed gas comprises in the range of from 40 to 99 v/v %, more preferably 50 to 98 v/v %, even more preferably 60 to 95 v/v % of methane.
  • the sour feed gas is contacted in a co-current contactor with a loaded liquid absorbent to obtain a gas/liquid mixture of pre-treated sour feed gas and further loaded liquid absorbent (pre-contactor step (a) ) .
  • the further loaded liquid absorbent is then separated from the gas/liquid mixture in separation step (b) and a gaseous stream of pre-treated sour feed gas and a liquid stream of further loaded liquid absorbent are obtained.
  • absorption step (c) the pre-treated sour feed gas obtained in
  • step (b) is counter-currently contacted with a lean liquid absorbent to obtain a purified gas and loaded liquid absorbent.
  • step (d) at least part of the liquid absorbent thus obtained is supplied to pre-contactor step
  • the process further comprises a regeneration step (e) wherein the liquid stream of further loaded liquid absorbent obtained in separation step (b) is regenerated in a regeneration unit to obtain a gas stream comprising acid gases that have been desorbed from the liquid absorbent, and a regenerated (lean) liquid absorbent, wherein the regenerated liquid absorbent is the liquid absorbent in step (c) .
  • pre-contactor step (a) at least part of the sour feed gas is contacted in a co-current contactor with a loaded liquid absorbent for absorbing part of the carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide.
  • the capacity of the counter-current absorber in step (c) all or part of the sour feed gas that is to be treated in absorption step (c) is contacted with the loaded liquid absorbent in pre- contactor step (a) . If only part of the sour feed gas is supplied to pre-contactor step (a) , the remainder of the sour feed gas is directly supplied to the counter-current absorber in step (c) , suitably together with the pre- treated sour gas.
  • liquid absorbent in step (a) is carried out such that acid gases can be absorbed in the liquid absorbent.
  • Suitable ways for absorption under co-current contacting conditions and suitable co-current contactors are well-known in the art .
  • the co-current contactor may for example comprise one or more tubes through which the sour feed gas and the
  • the sour feed gas and the loaded liquid absorbent are co-currently flowing under annular-dispersed flow conditions.
  • the co-current contactor may comprise one or more tubes provided with static mixers or other
  • pressure drop is suitably
  • the one or more tubes may have any suitable length
  • the one or more tubes preferably are
  • the one or more tubes may have any suitable length
  • the orientation is such that
  • liquid hold-up is promoted in order to increase liquid residence time, whilst significant pressure drop is
  • a suitable system is described in WO 2013/041515, said system comprising two or more separation units in series, said separation units comprising a rising conduit for transporting a contaminated gas stream into a separator and a descending conduit for removing separated liquid absorbent, and wherein the the descending conduit of a second separation unit is fluidly connected to the rising conduit of a first separation unit and wherein the height of the descending conduit of the second separation unit is selected such that during use the hydrostatic force in the descending conduit of the second separation unit can induce the liquid absorbent in the rising conduit of the first separation unit to flow to the inlet of the first separator.
  • the sour feed gas is co-currently
  • the gas flow velocity is maintained such that a dispersed annular flow regime is obtained comprising a multitude of small liquid droplets in a gas-continuous phase.
  • the annular dispersed (turbulent) flow conditions are characterized by a Reynolds number (based on gas density, gas velocity and gas viscosity) that exceeds 3000, more preferably exceeds 100000.
  • the sour feed gas is co-currently
  • the operational pressure of the co-current contactor section is either equal to the upstream
  • the highest of the upstream and downstream pressure is chosen, since this allows to have maximum sour gas treatment capacity in equipment of a given volume .
  • the co-current contactor comprises one or more conduits and the sour feed gas is co-currently
  • a co- current or compact contactor is defined as a conduit for gas and liquid, where gas and liquid flow in a co-current direction, and wherein the liquid contains a liquid
  • compact contactor can be selected from a range of options, including straight circular conduits in either horizontal or vertical orientation, straight circular conduits in combined horizontal and vertical orientations using
  • the co-current contactor is a tube-and-shell heat exchanger comprising a multitude of parallel conduits and having a conduit side and a shell side.
  • the sour feed gas is co-currently contacted with the loaded liquid absorbent at the tube side and a coolant is flowing at the shell side.
  • the loaded liquid absorbent that is supplied to pre- contactor step (a) is cooled during contacting with the sour feed gas in the co-current contactor.
  • the conduits suitably contain the high-pressure sour gas flow.
  • the shell only needs to contain the coolant, which is generally of much lower pressure than the sour process flow; this allows for designing the shell as a light weight
  • the tubes are preferably pepared of a material that is corrosion resistant.
  • the coolant is preferably non ⁇ toxic, non-flammable and/or non-corrosive, thus allowing for a low cost material for the shell side.
  • the shell-in- tube cooling topology is advantageous as it gives a high area for heat transfer between coolant and sour gas, while allowing for high process gas velocity, thus maximizing sour gas mass flow rate capacity.
  • the coolant can be suitably selected to be a liquid, a refrigerant, or a boiling flow, a phase change material.
  • reaction of liquid absorbent with C0 2 and/or H 2 S and/or S0 2 is an exothermic process which tends to increase the temperature of both gas and liquid.
  • Increasing temperature reduces gas density, thus increasing volumetric gas rates, which reduces the mass flow rate capacity, increases pressure drop and/or excessive
  • liquid absorbent has a large thermal capacity and large latent heat.
  • Conventional design approach selects the solvent always warmer than the feed gas in order to prevent
  • the absorber is operated at a temperature of at least 25 °C in order to avoid undesired formation of so-called gas hydrates. It has, however, been found that in the co-current contactor of the process according to the invention, the conditions are such that gas hydrates formed are decomposed as a result of exothermic heat produced in the absorption reaction.
  • the co-current contactor may be operated at a temperature at which gas hydrates may be formed, in
  • the temperature of the pre-treated sour feed gas obtained in step (b) which is fed to the counter- current absorption column in step (c) is in the range of 20-50 °C, more preferably 25-40 °C, most preferably about 30 °C. It is further preferred that liquid absorbent
  • step (a) entering the co-current contactor in step (a) has a
  • cooled loaded absorbent is injected in the warm gas/solvent mixture in such a proportion that the heat capacity of the cooled loaded absorbent is just sufficient to compensate for the exothermic heat of reaction of solvent and gaseous contaminant.
  • solvent is therefore advantageous to inject solvent in multiple axial locations of the co-current contactor, where the injection rates at each location and/or the temperature of injected absorbent is adjusted in such a way that the temperature is maintained at the optimum level.
  • Cooling of loaded liquid absorbent may be done by any means known in the art, for example by heat exchanging loaded liquid absorbent against a coolant such as air, water, seawater, or a refrigerant.
  • the process according to the invention is particularly suitable to be applied for purifying sour natural gas that is to be liquefied to produce liquefied natural gas (LNG) .
  • Cooling means or refrigerants that are available in a process for liquefying the natural gas can then advantageously be used to cool the loaded liquid absorbent prior to or during pre-contacting step (a) .
  • the process according to the invention can suitably be applied on a platform or floating vessel, in particular a platform or floating vessel for production of LNG, since these commonly have space and/or weight
  • step (a) sour feed gas is co-currently contacted with loaded liquid absorbent and a gas/liquid mixture of pre-treated sour feed gas and further loaded liquid
  • absorbent is obtained.
  • subsequent separation step (b) further loaded liquid absorbent is separated from the gas/liquid mixture, such that a gaseous stream of pre- treated sour feed gas and a liquid stream of further loaded absorbent are obtained.
  • the gaseous stream may still comprise minor amounts of further loaded liquid absorbent ("liquid carry-over") , preferably in an amount of at most 5 %, more preferably in the range of from 0-2 %, based on the mass flow of lean solvent entering the main (counter- current) absorber. Such remainders of liquid absorbent will be removed from the gaseous stream in subsequent absorption step (c) .
  • Step (b) may be carried out in any suitable gas/liquid separator.
  • Suitable gas/liquid separators are well-known in the art.
  • the separator may for example by a cyclonic
  • the separator may be an axial cyclone.
  • the separator may be an inline separator.
  • step (c) The loaded liquid absorbent obtained in step (c) , or a part thereof, is sent to step (a) .
  • This loaded liquid is sent to step (a) .
  • absorbent stream contains less loaded absorbent than the further loaded liquid absorbent obtained in separation step (b) .
  • the further loaded liquid absorbent obtained in separation step (b) can be regenerated in regeneration step (e) .
  • steps (a) and (b) Hence, a part of the sour feed gas used in step (a) is not processed in the absorption column of step (c) . This saves capacity in the absorption column of step (c) .
  • optimal removal can be achieved with at a relatively low solvent circulation rate.
  • step (a) is cooled prior to being supplied to step (a) and/or during contacting with the sour feed gas in step (a) .
  • step (c) This enhances the absorption capacity of the loaded liquid absorbent that is supplied to step (a) . This thus further reduces the amount of sour feed gas that is processed in the absorption column of step (c) . Additionally, when cooler pre-treated sour feed gas is obtained in step (b) , the absorption process in the absorption column of step (c) is more efficient.
  • the further loaded liquid absorbent is separated from the mixture obtained in step (a) directly downstream of the co-current contactor and upstream of the counter-current absorber.
  • Steps (a) and (b) may be carried out in a combined contactor/separation unit or in a series of multiple combined
  • contactor/separation units for example in a series of combined contactor/separation units as disclosed in WO 2013/041545.
  • WO 2013/041545 Preferably in such series-combined
  • the sour feed gas is co- currently contacted with liquid absorbent that is separated from the subsequent combined contactor/separation unit.
  • liquid absorbent that is separated from the subsequent combined contactor/separation unit.
  • step (a) Pre-treated sour feed gas obtained after gas/liquid separation in the final combined
  • contactor/separation unit is then supplied to the counter- current absorber in step (c) .
  • steps (a) and (b) are carried out in a system as disclosed in WO2013/041545 comprising at least two contactor/separation units in series.
  • An advantage of using the system of WO2013/041545 is that it can be used subsea, or more general underwater. If used subsea, the loaded liquid absorbent is suitably cooled by seawater and no additional means for cooling might be needed.
  • separation step (b) may be carried out in a bottom section of the counter-current absorber.
  • the gas/liquid mixture of pre-treated sour feed gas and further loaded liquid absorbent is then introduced in the bottom section of the counter-current absorber. It is important that flashing of carbon dioxide or other acid gases from the further loaded absorbent upon introduction of the mixture into the counter-current absorber, is prevented. Therefore, the gas/liquid mixture is preferably introduced into the bottom section of the counter-current absorber.
  • step (c) minimizing thermal and spatial contact between said further loaded liquid absorbent and the liquid absorbent supplied to the absorption column in step (c) .
  • This is suitably achieved by providing a liquid tray in a bottom section of the absorption column, wherein said liquid tray is
  • absorption step (c) the pre-treated sour feed gas obtained in separation step (b) is counter-currently contacted with a liquid absorbent for absorbing carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide in an counter-current absorber to obtain the purified gas stream and loaded liquid absorbent.
  • a liquid absorbent for absorbing carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide in an counter-current absorber to obtain the purified gas stream and loaded liquid absorbent.
  • the liquid absorbent may be any liquid capable of removing carbon dioxide and/hydrogen sulphide and/or
  • a preferred liquid absorbent comprises a chemical solvent as well as a physical solvent.
  • Suitable chemical and physical solvents are known in the art. Any suitable solvents known in the art may be used.
  • a preferred chemical solvent is a secondary or tertiary amine, more preferably an amine compound derived from ethanol amine, more
  • DIPA dimethyl-ethanolamine
  • MMEA monomethyl-ethanolamine
  • MDEA dimethyl-ethanolamine
  • DEMEA diethyl-monoethanolamine
  • Suitable physical solvents are sulfolane (cyclo- tetramethylenesulfone) and its derivatives, aliphatic acid amides, N-methylpyrrolidone, N-alkylated pyrrolidones and the corresponding piperidones, methanol, ethanol and
  • dialkylethers of polyethylene glycols or mixtures thereof The preferred physical solvent is sulfolane.
  • the liquid absorbent may further comprise a so-called activator
  • Suitable activator compounds are piperazine, methyl-ethanolamine, or (2-aminoethyl) ethanolamine,
  • a particularly preferred liquid absorbent comprises sulfolane, MDEA and piperazine.
  • the liquid absorbent typically comprises water,
  • absorption step (c) is carried out at a temperature in the range of from 0 to 100 °C, more preferably from 25 to 40 °C, still more preferably from 30 to 45 °C.
  • the liquid absorption is suitably carried out at a pressure between 10 and 150 bar (absolute) , preferably between 25 and 90 bar (absolute) .
  • absorption is carried out in the dense phase.
  • step (d) at least a part of the loaded liquid absorbent obtained in step (c) is supplied to step (a) .
  • step (c) preferably 70 to 100%, still more preferably 85 to 100%, still more preferably 95 to 100%, of the loaded liquid absorbent obtained in step (c) to step (a) .
  • the purified gas stream obtained in step (a) is depleted in carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide, meaning that the concentration of carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide in the purified gas stream is lower than the concentration of hydrogen sulphide in the feed gas stream. It will be understood that the concentration of carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide in the purified gas stream obtained in step (c) will depend on the carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide concentration in the sour feed gas and the conditions applied in steps (a) to (c) .
  • the sour feed gas comprises carbon dioxide in a concentration in the range of from 5 to 90 mol%, preferably of from 10 to 90 mol%, more preferably of from 20 to 60 mol%.
  • step (a) is placed in series with the absorption column of step (c) .
  • loaded liquid absorbent comprising contaminants such as carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide and optionally other contaminating compounds such as carbonyl sulphide, carbon disulphide or mercaptans is obtained. At least part of the loaded liquid absorbent is supplied to step (a) to serve as the loaded liquid absorbent in step (a) . If not all loaded liquid absorbent is supplied to step (a) , the remainder of the loaded liquid absorbent is preferably regenerated in optional regeneration step (e) , together with the further loaded liquid absorbent obtained in separation step (b) .
  • step (e) the liquid stream of further loaded liquid absorbent obtained in separation step (b) , optionally together with part of the loaded liquid absorbent obtained in step (c) , is regenerated by transferring at least part of the contaminants to a
  • regeneration gas stream Regeneration of loaded liquid absorbent is well-known in the art and any suitable
  • regeneration takes place at relatively low pressure and high temperature.
  • the regeneration is suitably carried out by heating in a regenerator at a relatively high
  • the heating is preferably carried out with steam or hot oil in a reboiler.
  • the temperature increase is done in a stepwise mode.
  • regeneration is carried out at a pressure in the range of from 1 to 10 bara, more suitably 1-3 bara.
  • contactor receives both loaded liquid absorbent from counter-current absorption step (c) and semi-loaded liquid absorbent obtained by flashing part of the further-loaded liquid absorbent obtained in step (b) prior to regeneration of the remaining further-loaded liquid absorbent.
  • regenerated liquid absorbent (lean absorbent) is obtained and a sour gas stream comprising carbon dioxide and/or hydrogen sulphide and/or sulphur dioxide.
  • the regenerated absorbing liquid thus obtained is preferably used as the liquid absorbent in step absorption step (c) .
  • the heat and steam duty may be reduced by flashing regenerated liquid absorbent to obtain a stream of liquid lean
  • absorbent that may be used in absorption step (c) and a gaseous stream of lean absorbent that may be recycled, after recompression to the pressure of the regenerator, to the regenerator to provide additional steam.
  • a further possibility to reduce heat and steam duty is to flash steam condensate from the reboiler of the regenerator and to introduce flashed steam condensate as additional stripping steam into the regenerator.
  • a sour feed gas comprising carbon dioxide and hydrogen sulphide is supplied to step (a) to obtain a mixture of pre-treated sour feed gas comprising carbon dioxide and further loaded liquid absorbent comprising absorbed hydrogen sulphide, and wherein the pre-treated sour feed gas comprising carbon dioxide obtained in separation step (b) is contacted in step (c) in an absorption tower counter-currently with a liquid absorbent for absorbing carbon dioxide, and wherein the further loaded liquid absorbent comprising absorbed hydrogen sulphide obtained in separation step (b) is
  • Figure 1 illustrates a process line-up according to the invention. Sour gas (1) is contacted co-currently with a loaded liquid absorbent (2) in a co-current contactor (3) .
  • the obtained mixture is separated in a separator (4) into a pre-treated sour feed gas (5) and a liquid stream of further loaded liquid absorbent (11) .
  • pre-treated sour feed gas (5) is contacted counter-currently with a liquid absorbent (7) .
  • absorbent (2) are obtained. Loaded liquid absorbent (2) is cooled (10) prior to being supplied to the co-current contactor (3) .
  • the further loaded liquid absorbent (11) is
  • Regenerated liquid absorbent (7) is used in absorption column (6) .
  • Figure 2 illustrates a series of contactor/separation units according to the invention. Sour gas (1) is contacted co-currently with a loaded liquid absorbent (40) in a co- current contactor (3) .
  • C02 and/or H2S and/or S02 is/are absorbed by the loaded liquid absorbent (40) .
  • a mixture of a pre-treated sour feed gas and a further loaded liquid absorbent is obtained.
  • the obtained mixture is separated in a
  • the further loaded liquid absorbent (50) is
  • Pre-treated sour feed gas (15) is sent to a further contactor/separation unit (13, 14) .
  • a liquid stream of loaded liquid absorbent (40) is recycled to co-current contactor (3) .
  • pre-treated sour feed gas (25) is contacted co-currently with a loaded liquid absorbent (60) from an absorber (not shown) in co-current contactor (23) .
  • the obtained mixture is separated in a separator (24) .
  • Even further pre-treated sour feed gas (35) is sent to an absorber (not shown) .

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

Abstract

L'invention concerne un procédé de production d'un gaz purifié à partir d'un gaz d'alimentation acide comprenant les étapes suivantes consistant à : (a) mettre en contact de manière concourante un gaz d'alimentation acide avec un absorbant liquide chargé pour absorber CO2 et/ou H2S et/ou SO2 et obtenir un mélange de gaz d'alimentation acide pré-traité et un absorbant liquide chargé; (b) séparer l'absorbant liquide chargé; (c) mettre en contact le gaz d'alimentation acide pré-traité obtenu dans l'étape (b) de manière concourante avec un absorbant liquide pour absorber CO2 et/ou H2S et/ou SO2 et obtenir le gaz purifié et un absorbant liquide chargé; et (d) acheminer l'absorbant liquide chargé obtenu à l'étape (c) vers l'étape (a). L'absorbant liquide chargé obtenu à l'étape (c) qui est acheminé vers l'étape (a) est refroidi.
PCT/EP2015/065513 2014-07-07 2015-07-07 Procédé de production d'un courant de gaz purifié par absorption à deux étages WO2016005402A1 (fr)

Applications Claiming Priority (2)

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EP14176032 2014-07-07
EP14176032.2 2014-07-07

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WO2016005402A1 true WO2016005402A1 (fr) 2016-01-14

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3068262A1 (fr) * 2017-06-28 2019-01-04 Gaz De Ferme Systeme de separation et d'epuration de deux gaz constitutifs d'un melange gazeux

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0204847A2 (fr) * 1985-02-22 1986-12-17 GebràœDer Sulzer Aktiengesellschaft Procédé d'absorption sélective d'hydrogène sulfuré d'un gaz contenant l'hydrogène sulfuré et du dioxyde de carbone et dispositif pour réaliser le procédé
GB2383276A (en) * 2001-12-21 2003-06-25 Statoil Asa Removal of acidic components from a gas stream
WO2011009902A1 (fr) * 2009-07-22 2011-01-27 Hitachi Power Europe Gmbh Purification de gaz de combustion au moyen d’un lavage par jet de co2 en plusieurs étapes
US20110305616A1 (en) * 2010-06-09 2011-12-15 Uop Llc Configuration of contacting zones in vapor liquid contacting apparatuses
US20130340623A1 (en) * 2011-04-13 2013-12-26 The Kansai Electric Power Co., Inc. Co2 recovery device
US20140090556A1 (en) * 2011-03-16 2014-04-03 Aker Process Systems As Method and system for gas purification with first direct absorption step and second absorption step by means of membrane contactor

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0204847A2 (fr) * 1985-02-22 1986-12-17 GebràœDer Sulzer Aktiengesellschaft Procédé d'absorption sélective d'hydrogène sulfuré d'un gaz contenant l'hydrogène sulfuré et du dioxyde de carbone et dispositif pour réaliser le procédé
GB2383276A (en) * 2001-12-21 2003-06-25 Statoil Asa Removal of acidic components from a gas stream
WO2011009902A1 (fr) * 2009-07-22 2011-01-27 Hitachi Power Europe Gmbh Purification de gaz de combustion au moyen d’un lavage par jet de co2 en plusieurs étapes
US20110305616A1 (en) * 2010-06-09 2011-12-15 Uop Llc Configuration of contacting zones in vapor liquid contacting apparatuses
US20140090556A1 (en) * 2011-03-16 2014-04-03 Aker Process Systems As Method and system for gas purification with first direct absorption step and second absorption step by means of membrane contactor
US20130340623A1 (en) * 2011-04-13 2013-12-26 The Kansai Electric Power Co., Inc. Co2 recovery device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3068262A1 (fr) * 2017-06-28 2019-01-04 Gaz De Ferme Systeme de separation et d'epuration de deux gaz constitutifs d'un melange gazeux
EP3421114A3 (fr) * 2017-06-28 2019-03-20 Gaz de Ferme Systeme de separation et d'epuration de deux gaz constitutifs d'un melange gazeux

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