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WO2012089781A1 - Process for removing sulphur-containing contaminants from a gas stream - Google Patents

Process for removing sulphur-containing contaminants from a gas stream Download PDF

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Publication number
WO2012089781A1
WO2012089781A1 PCT/EP2011/074185 EP2011074185W WO2012089781A1 WO 2012089781 A1 WO2012089781 A1 WO 2012089781A1 EP 2011074185 W EP2011074185 W EP 2011074185W WO 2012089781 A1 WO2012089781 A1 WO 2012089781A1
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WO
WIPO (PCT)
Prior art keywords
gas stream
hydrogen sulphide
sulphur
sulphur dioxide
enriched
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
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PCT/EP2011/074185
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French (fr)
Inventor
Diego Patricio VALENZUELA
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Shell Internationale Research Maatschappij BV
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Shell Internationale Research Maatschappij BV
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Publication of WO2012089781A1 publication Critical patent/WO2012089781A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8603—Removing sulfur compounds
    • B01D53/8612—Hydrogen sulfide
    • B01D53/8615—Mixtures of hydrogen sulfide and sulfur oxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8603—Removing sulfur compounds
    • B01D53/8612—Hydrogen sulfide
    • B01D53/8618—Mixtures of hydrogen sulfide and carbon dioxides
    • 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
    • C01B17/0404—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides by processes comprising a dry catalytic conversion of hydrogen sulfide-containing gases, e.g. the Claus process
    • 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
    • C01B17/0404—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides by processes comprising a dry catalytic conversion of hydrogen sulfide-containing gases, e.g. the Claus process
    • C01B17/0426—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides by processes comprising a dry catalytic conversion of hydrogen sulfide-containing gases, e.g. the Claus process characterised by the catalytic conversion
    • C01B17/0434—Catalyst compositions
    • 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
    • C01B17/0404—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides by processes comprising a dry catalytic conversion of hydrogen sulfide-containing gases, e.g. the Claus process
    • C01B17/0456—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides by processes comprising a dry catalytic conversion of hydrogen sulfide-containing gases, e.g. the Claus process the hydrogen sulfide-containing gas being a Claus process tail gas
    • 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
    • C01B17/0473—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides by reaction of sulfur dioxide or sulfur trioxide containing gases with reducing agents other than 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
    • B01D2257/304—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
    • 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
    • B01D53/1475—Removing 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 present invention relates to a process for removing sulphur-containing contaminants, including hydrogen sulphide, from a gas stream.
  • the Claus process is a two-step process that includes a burner (oxidation) step followed by a catalytic step wherein use is made of one or more catalytic stages.
  • oxidation step the hydrogen sulphide of a feed stream is partially oxidized by combustion with oxygen to form a gas containing sulphur dioxide.
  • the unreacted hydrogen sulphide and the formed sulphur dioxide contained in the combustion gas can undergo the Claus reaction whereby they are reacted to form elemental sulphur.
  • the tail gas from a Claus process therefore is usually subjected to a hydrogenation treatment to further reduce the amounts of sulphur dioxide, COS, CS 2 , and mercaptans by converting them into hydrogen sulphide, followed by a treatment wherein use is made of an amine that selectively absorbs hydrogen sulphide.
  • a hydrogenation treatment to further reduce the amounts of sulphur dioxide, COS, CS 2 , and mercaptans by converting them into hydrogen sulphide
  • a treatment wherein use is made of an amine that selectively absorbs hydrogen sulphide Upon regeneration of the hydrogen sulphide-rich amine stream a gas stream enriched in hydrogen sulphide can be recovered which can subsequently be recycled to the Claus unit.
  • the combination of the hydrogenation and amine treatments can be a so-called SCOT process.
  • the tail gas subjected to such a SCOT process still contains noticeable amounts of hydrogen sulphide (in the order of 100 ppm sulphur)
  • the present invention relates to a process for removing contaminants, including hydrogen sulphide, from a gas stream comprising the steps of:
  • step (b) extracting heat from the gas stream as obtained in step (a) ;
  • step (c) reacting hydrogen sulphide present in the cooled gas stream as obtained in step (b) with sulphur dioxide at elevated temperature and in the presence of a catalyst to obtain a gas stream which comprises sulphur and water;
  • step (c) thereby obtaining a hydrogen sulphide lean gas stream
  • step (e) subjecting a sulphur-containing residual hydrocarbon product to an oxidation treatment to obtain a gas stream which comprises sulphur dioxide; (f) extracting heat from the gas stream which comprises sulphur dioxide as obtained in step (e) ;
  • step (g) subjecting at least part of the cooled gas stream as obtained in step (f) to a quench process; (h) contacting at least part of the gas stream as obtained in step (g) with an absorption solvent that absorbs sulphur dioxide to obtain a sulphur dioxide- enriched absorption solvent and a sulphur dioxide- depleted gas stream;
  • step (i) removing sulphur dioxide from at least part of the sulphur dioxide-enriched adsorption solvent as obtained in step (h) to obtain a sulphur dioxide- depleted absorption solvent and a sulphur dioxide- enriched gas stream;
  • step (j) passing at least part of the sulphur dioxide- enriched gas stream as obtained in step (i) to step (c) ;
  • step (k) contacting at least part of the hydrogen sulphide lean gas stream as obtained in step (d) with a reducing agent and a catalyst to obtain an hydrogen sulphide-enriched gas stream;
  • step (k) extracting heat from the hydrogen sulphide- enriched gas stream as obtained in step (k);
  • step (1) subjecting at least part of the cooled gas stream as obtained in step (1) to a quench process
  • step (n) contacting at least part of the hydrogen sulphide-enriched gas stream as obtained in step (m) with an absorption solvent that absorbs hydrogen sulphide to obtain a hydrogen sulphide-enriched absorption solvent and a hydrogen sulphide-depleted gas stream;
  • step (o) removing hydrogen sulphide from at least part of the hydrogen sulphide-enriched absorption solvent as obtained in step (n) to obtain a hydrogen
  • step (p) recycling at least part of the hydrogen sulphide-enriched gas stream as obtained in step (o) to step (a) .
  • gas streams can be obtained that contain such small amounts of sulphur-containing contaminants that they can
  • the present invention relates to a process for removing sulphur-containing contaminants, including hydrogen sulphide, from an acid gas stream.
  • the acid gas stream to be treated in accordance with the present invention can be any gas stream comprising sulphur- containing contaminants.
  • the process according to the invention is especially suitable for gas streams
  • the total gas stream to be treated comprises in the range of from 40 to 100 vol% hydrogen sulphide and from 0 to 60 vol% carbon dioxide, based on the total gas stream.
  • the gas stream to be treated comprises from 55 to 100 vol% hydrogen sulphide and from 0 to 45 vol% carbon dioxide, based on the total gas stream.
  • step (a) the oxidation treatment is carried at a temperature in the range of from 980-2000 °C, preferably in the range of from 1090-1540 °C, and a pressure in the range of from 1.29-2.05 bara, preferably in the range of from 1.56-2.05 bara.
  • the molar ratio of hydrogen sulphide to oxide in step (a) is in the range of from 2:1-3:1.
  • Step (a) can suitably be carried out in a burner.
  • the gas stream Prior to such an oxidation treatment in step (a) the gas stream can suitably be subjected to an enrichment
  • the gas stream to be subjected to the oxidation treatment in step (a) contains hydrogen sulphide in an amount in the range of 45-100 mole %, based on total gas stream.
  • step (b) heat is extracted from the gas stream as obtained in step (a) .
  • This can suitably be done by cooling the gas stream in a two-step heat recovery unit to a temperature range 163-177 °C, preferable to a range between 168-174 °C.
  • a Waste Heat Boiler can suitably be used to generate high to medium pressure steam by cooling the gases to 260-370 °C, preferable to 315-343 °C.
  • low pressure steam can suitably be generated by cooling the gas stream to a temperature range 163-177 °C, preferable to a range between 168-174 °C. It is believed that at these
  • step (c) use can be made of one or more catalytic stages, whereby after each respective catalytic stage sulphur can be separated from the gas stream as described in step (d) .
  • step (d) the separation of sulphur from the gas stream can suitably be carried out by means of a sulphur condensation unit.
  • step (c) hydrogen sulphide present in the cooled gas stream as obtained in step (b) can be reacted with sulphur dioxide at elevated temperature in a first catalytic stage to obtain a gas stream which comprises sulphur and water.
  • step (c) comprises a
  • the first catalytic stage is carried out in a catalytic zone where hydrogen sulphide reacts with sulphur dioxide to produce more sulphur.
  • the reaction in the first catalytic stage is carried out with a Claus conversion catalyst at a
  • a second and a third catalytic stage can be used in step (c) in which stages use is made of a Claus conversion catalyst.
  • the reaction is carried out at a temperature which is 5 to 20 °C above the sulphur dew point, preferable at a temperature which is 10 to 15 °C above the sulphur dew point, and a pressure in the range of from 1-2 bara, preferably in the range of from 1.4-1.7 bara.
  • hydrogen sulphide to sulphur dioxide in step (c) is in the range of from 2:1-3:1.
  • Sulphur condensation units can suitably be applied after each catalytic stage in step (c) , which
  • condensation units can suitably be operated at
  • Claus tail gases gases contain nitrogen, water vapour, some hydrogen sulphide, sulphur dioxide and usually also carbon
  • a suitable Claus catalyst has for instance been described in European patent application No. 0038741, which catalyst substantially consists of titanium oxide.
  • Other suitable catalysts include activated alumina and bauxite catalysts.
  • step (d) sulphur is separated from the gas stream obtained in step (c) , thereby obtaining a hydrogen sulphide-lean gas stream.
  • the gas stream as obtained in step (c) can be cooled below the sulphur dew point to condense and subsequently most of the sulphur obtained can be separated from the gas stream.
  • step (d) can suitably be carried out by cooling the effluent obtained in step (c) to condense and separate sulphur, thereby obtaining the hydrogen sulphide-depleted gas stream.
  • step (e) a sulphur-containing residual hydrocarbon product is subjected to an oxidation treatment to obtain a gas stream which comprises sulphur dioxide.
  • the oxidation treatment is preferably carried at a temperature in the range of from 538-1038 °C, preferably in the range of from 648-982 °C, and a pressure in the range of from 1-2 bara, preferably in the range of from 1.4-1.7 bara .
  • step (e) any sulphur-containing residual
  • the sulphur-containing residual hydrocarbon product to be used in step (e) is preferably a product from a thermal gasoil unit having a V50 (viscosity at 50 °C) in the range of from 30-50 cSt, a product from a catalytic cracking unit, suitably in slurry form, having a V50 in the range of from 20-50 cSt, or a heavy residue containing up to 10 wt% organic sulphur, based on total heavy residue. More preferably, the residual hydrocarbon product comprises a product from a thermal gasoil unit having a V50 in the range of from 35-45 cSt.
  • the integration of step (e) advantageously ensures that the size of the Claus unit to be used can be reduced or that the capacity of the Claus unit can be increased .
  • step (f) heat is extracted from the gas stream which comprises sulphur dioxide as obtained in step (e) .
  • step (f) can be carried out in a similar way as the heat extraction in step (b) as
  • step (g) at least part of the cooled sulphur dioxide-enriched gas stream as obtained in step (f) is subjected to a quenching process before is contacted with the absorption solvent in step (h) .
  • the respective gas streams are suitably cooled by means of water quenching.
  • step (f) is subjected to the quenching process before is contacted with the absorption solvent in step (h) .
  • these gas streams are cooled to a temperature in the range of from 40-60 °C in the quenching process.
  • step (h) at least part of the sulphur dioxide-enriched gas stream as obtained in step (g) is contacted with an absorption solvent that absorbs sulphur dioxide to obtain a sulphur dioxide-enriched absorption solvent and a sulphur dioxide-depleted gas stream.
  • step (h) use is made of an aqueous solution of the absorption solvent.
  • step (g) 10-90 vol.% of the gas stream as obtained in step (g) can be contacted with the absorption solvent in step (h) .
  • the entire gas stream as obtained in step (g) is contacted with the absorption solvent in step (h) .
  • the absorption solvent in step (h) comprises water and a water-soluble amine absorbent having at least one amine group with a pKa value greater than about 7 and at least one other amine group with a pKa value less than 6.5, wherein the at least one amine group with a pKa value greater than about 7 irreversibly absorbs sulphur dioxide in salt form to render the amine absorbent non-volatile, and wherein the at least one other amine group with a pKa value less than 6.5
  • the water-soluble amine absorbent is a diamine having the general formula:
  • Ri is an alkylene group having 1 to 3 carbon atoms
  • R 2 , R 3 , R and R5 are the same or different and each represent a hydrogen atom, a lower alkyl group having 1 to 8 carbon atoms or a lower hydroxy-alkyl group having 2 to 8 carbon atoms, or any of R 2 , R 3 , R and R5 form together with the nitrogen atoms to which they are attached a 6-membered ring.
  • the diamine is selected from the group consisting of N, N ' , N ' - ( trimethyl ) -N- ( 2- hydroxyethyl ) -ethylenediamine ;
  • step (h) the sulphur dioxide- enriched absorption solvent as obtained in step (h) will need to be regenerated in order to ensure that the absorption solvent can be used again in step (h) .
  • the sulphur dioxide-enriched absorption solvent as obtained in step (h) will normally be passed to a regeneration unit step (i) where the absorption solvent will be freed from sulphur oxide and the sulphur oxide-depleted absorption solvent so obtained can suitably be recycled to step (h) .
  • Step (h) can suitably be carried at a temperature in the range of from 20-80 °C, preferably in the range of from 30-60 °C, and a pressure in the range of from 1.1-2 bara, preferably in the range of from 1.4-1.7 bara.
  • step (h) use is made in step (h) of an aqueous solution that comprises the absorption solvent in a concentration in the range of from 30-55 w% .
  • At least part of the sulphur dioxide-depleted gas stream as obtained in step (h) is contacted with an absorption solvent to absorb carbon dioxide to obtain a carbon dioxide-enriched absorption solvent and a sulphur dioxide-depleted gas stream which is lean in carbon dioxide, and carbon dioxide is removed from at least part of the carbon dioxide-enriched adsorption solvent to obtain a carbon dioxide-depleted absorption solvent and a carbon dioxide-enriched gas stream.
  • the entire sulphur dioxide-depleted gas stream as obtained in step (h) is contacted with an absorption solvent to absorb carbon dioxide to obtain a carbon dioxide-enriched absorption solvent and a sulphur dioxide-depleted gas stream which is lean in carbon dioxide, and carbon dioxide is removed from at least part of the carbon dioxide-enriched adsorption solvent to obtain a carbon dioxide-depleted absorption solvent and a carbon dioxide-enriched gas stream.
  • the sulphur dioxide-depleted gas stream as obtained in step (h) is highly attractive since it is lean in respect of sulphur-containing contaminants.
  • the sulphur dioxide-depleted gas stream as obtained in step (h) contains no hydrogen sulphide and less than 50 ppmv sulphur dioxide.
  • said gas stream contains less than 30 ppmv sulphur dioxide.
  • step (i) sulphur dioxide is removed from at least part of the sulphur dioxide-enriched adsorption solvent as obtained in step (h) to obtain a sulphur dioxide- depleted absorption solvent and a sulphur dioxide- enriched gas stream.
  • at least part of the sulphur dioxide-depleted absorption solvent as obtained in step (i) is recycled to step (h) .
  • the entire sulphur dioxide-depleted absorption solvent as obtained in step (i) is recycled to step (h) .
  • Step (i) can suitably be carried at a temperature in the range of from 110-150 °C, preferably in the range of from 120-140 °C, and a pressure in the range of from 1.1-1.9 bara, preferably in the range of from 1.2-1.7 bara .
  • step (j) at least part of the sulphur dioxide- enriched gas stream as obtained in step (i) is passed to step (c) .
  • step (c) the entire sulphur dioxide- enriched gas stream as obtained in step (i) is passed to step (c) .
  • step (k) at least part of the hydrogen sulphide lean gas stream as obtained in step (d) is subjected to a hydrogenation treatment to obtain a hydrogen sulphide- enriched gas stream.
  • step (k) the amounts of sulphur dioxide, COS, CS2, and mercaptants are further reduced by converting these contaminants into hydrogen sulphide.
  • step (k) the entire hydrogen sulphide lean gas stream as obtained in step (d) is subjected to the hydrogenation treatment to obtain a hydrogen sulphide- enriched gas stream.
  • step (k) suitably use is made of a reducing agent and a catalyst. Step (k) can suitably be carried out at a temperature in the range of from
  • step (k) is carried out at a
  • the reducing agent to be used in step (g) is hydrogen.
  • this hydrogen is produced in the oxidizing burner in step
  • Suitable the hydrogen is present in an amount of 1-5 mole %, based on total gas stream.
  • step (1) heat is extracted from the hydrogen sulphide-enriched gas stream as obtained in step (k) .
  • the heat extraction in step (1) can be carried out in a similar way as the heat extraction in step (b) as
  • step (m) at least part of the cooled hydrogen sulphide-enriched gas stream as obtained in step (1) is subjected to a quenching process.
  • the quenching process in step (m) can be carried out in a similar way as the quenching process in step (g) as described hereinbefore.
  • step (n) at least part of hydrogen-sulphide- enriched gas stream as obtained in step (m) is contacted with an absorption solvent that absorbs hydrogen sulphide to obtain a hydrogen sulphide-enriched absorption solvent and a hydrogen sulphide-depleted gas stream.
  • at least part of the hydrogen sulphide-enriched gas stream as obtained in step (1) is subjected to a quenching treatment before it is contacted with the absorption solvent in step (n) .
  • a quenching step the
  • respective gas streams are suitably cooled by means of water quenching.
  • the entire gas stream which comprises sulphur dioxide as obtained in step (1) is subjected to the quenching treatment before it is
  • step (n) contacted with the absorption solvent in step (n) .
  • the gas stream is cooled to a temperature in the range of from 40-60 °C in the quenching step.
  • the entire gas stream obtained from the quenching step is contacted with the absorption solvent in step (n) .
  • the absorption solvent in step (m) comprises water, and an amine.
  • a physical solvent can be present.
  • the physical solvent comprises sulfolane.
  • Suitable amines to be used in step (m) include primary, secondary and/or tertiary amines, especially amines that are derived of ethanolamine, especially monoethanol amine (MEA) , diethanolamine (DEA) ,
  • TSA triethanolamine
  • DIPA diisopropanolamine
  • MDEA methyldiethanolamine
  • a preferred amine is a secondary or tertiary amine, preferably an amine compound derived from ethanol amine, more especially DIPA, DEA, MMEA (monomethyl- ethanolamine) , MDEA, or DEMEA (diethyl- monoethanolamine ) , preferably DIPA or MDEA.
  • Suitable physical solvents are sulfolane (cyclo- tetramethylenesulfone and its derivatives), aliphatic acid amides, N-methylpyrrolidone, N-alkylated
  • methanol ethanol
  • dialkylethers of polyethylene glycols or mixtures thereof.
  • the preferred physical solvent is sulfolane.
  • step (n) is carried out at a temperature in the range of from 20-60 °C, preferably at a temperature of at least 25 °C, more preferably in the range of from
  • Step (m) is suitably carried out at a pressure in the range of from 1.1 - 1.5 bara, preferably in the range of from 1.1-1.5 bara, more preferably in the range of from 1.1-1.4 bara.
  • the gas stream obtained in step (n) is attractively depleted of hydrogen sulphide and various other sulphur- containing contaminants.
  • concentration of hydrogen sulphide in the gas stream obtained in step (n) is suitably less than 200 ppmv, preferably less than 100 ppmv .
  • step (n) the hydrogen sulphide-enriched
  • absorption liquid will also comprise carbon dioxide and other sulphur compounds such as carbonyl sulphides and carbon disulphide.
  • step (o) hydrogen sulphide will be removed from at least part of the hydrogen sulphide-enriched absorption solvent as obtained in step (n) to obtain a hydrogen sulphide-depleted absorption solvent and a hydrogen sulphide-enriched gas stream.
  • step (o) suitably comprises the regeneration of the sulphur compounds- enriched absorption solvent.
  • the sulphur compounds-enriched absorption solvent is suitably contacted with regeneration gas and/or heated and can be depressurised, thereby transferring at least part of the contaminants to the regeneration gas. Typically, regeneration takes place at relatively low pressure and high temperature.
  • the regeneration in step (o) is suitably carried out by heating in a regenerator at a relatively high temperature, suitably in the range of from 110-160 °C.
  • the heating is preferably carried out with steam or hot oil.
  • a direct fired reboiler can be applied, if desired.
  • regeneration is carried out at a pressure in the range of from 1.1-1.9 bara.
  • regenerated absorption solvent i.e. a hydrogen sulphide-depleted absorption solvent
  • a regeneration gas stream enriched with contaminants such as hydrogen sulphide and carbon dioxide is obtained and a regeneration gas stream enriched with contaminants such as hydrogen sulphide and carbon dioxide.
  • at least part of the hydrogen sulphide-depleted absorption solvent as obtained in step (o) is recycled to step (n) .
  • the entire hydrogen sulphide-depleted absorption solvent as obtained in step (o) is recycled to step (n) .
  • the regenerated absorption solvent is heat exchanged with contaminants enriched absorption solvent to use the heat elsewhere.
  • the regenerated absorption solvent is heat exchanged with contaminants enriched absorption solvent to use the heat elsewhere.
  • step (p) at least part of the hydrogen sulphide- enriched gas stream as obtained in step (o) is recycled to step (a) .
  • step (p) the entire hydrogen sulphide-enriched gas stream as obtained in step (o) is recycled to step (a) .
  • a gas stream comprising sulphur- containing contaminants, including hydrogen sulphide is led via line 1 to an oxidation and heat recovery unit 2 (e.g. a combined burner and heat recovery unit) wherein the gas stream is oxidized and cooled while producing steam which is removed via line 3. Liquid sulphur which is condensed at the low temperature range is also removed via line 3. From unit 2 the gas stream obtained is passed via line 4 to a catalyst and sulphur separation unit 5.
  • an oxidation and heat recovery unit 2 e.g. a combined burner and heat recovery unit
  • oxidation and heat recovery unit 7 a residual hydrocarbon product, introduced via line 6, is subjected to an oxidation treatment to obtain a gas stream which comprises sulphur dioxide. Heat recovered in the
  • oxidation and heat recovery unit 7 is then removed via line 8.
  • the gas stream obtained in oxidation and heat recovery unit 7 is passed via line 9 into a quenching unit 10.
  • the quenching medium e.g. water, can be
  • the gas stream obtained in the quenching unit 10 is subsequently passed via line 12 to absorption/regeneration unit 13 where it is contacted with an absorption solvent that absorbs sulphur dioxide to obtain a sulphur dioxide- enriched absorption solvent and a sulphur dioxide- depleted gas stream.
  • the sulphur dioxide-enriched absorption solvent that absorbs sulphur dioxide
  • absorption solvent is then regenerated and sulphur dioxide-enriched gas stream thereby obtained is separated from the regenerated absorption solvent and send via line 15 to the catalytic and sulphur separation unit 5.
  • Regenerated solvent is removed via line 14.
  • unit 5 the hydrogen sulphide in the gas stream is reacted with sulphur dioxide in the presence of a
  • the catalyst to obtain a gas stream which comprises sulphur and water, whereby sulphur is withdrawn via line 16.
  • Low pressure steam generated in sulphur condensers in unit 5 can also be removed via line 16.
  • the hydrogen sulphide- lean gas stream (tail gas) so obtained is passed via line 17 into hydrogenation unit 18 to obtain by means of a reducing agent and a catalyst a hydrogen sulphide- enriched gas stream. Steam produced in the subsequent cooling stages is removed via line 19.
  • the hydrogen sulphide-enriched gas stream so obtained is passed via line 20 to a quenching unit 21.
  • the quenching medium e.g. water, can be withdrawn from the quenching unit 21 via line 22.
  • the gas stream obtained in the quenching unit 21 is subsequently passed via line 23 to
  • absorption/regeneration unit 24 where it is contacted with an absorption solvent that absorbs hydrogen sulphide to obtain a hydrogen sulphide-enriched absorption solvent and a hydrogen sulphide-depleted gas stream.
  • the hydrogen sulphide-enriched absorption solvent is then regenerated and hydrogen sulphide-enriched gas stream thereby
  • an acid gas comprising 60 % (v/v) hydrogen sulphide, 40 % (v/v) carbon dioxide, 0 % (v/v) sulphur dioxide, 50 ppmv carbonyl sulphide (COS), 200 ppmv mercaptans and 20 ppmv carbon disulphide is routed via line 1 to an oxidation and heat recovery unit 2 with a flow rate of 6.74 Nm 3 /s.
  • COS ppmv carbonyl sulphide
  • 200 ppmv mercaptans 200 ppmv mercaptans
  • 20 ppmv carbon disulphide is routed via line 1 to an oxidation and heat recovery unit 2 with a flow rate of 6.74 Nm 3 /s.
  • an oxidation and heat recovery unit 2 the acid gas is oxidized at a temperature of 980 °C and a pressure of 1.5 bara.
  • the molar ratio of hydrogen sulphide to oxide in unit 2 is 2:1.
  • the gas stream so obtained gas is passed via line 4 to catalyst and sulphur separation unit 5.
  • a sulphur-containing residual hydrocarbon product is routed via line 6 to an oxidation and heat recovery unit 7 with a flow rate of 7.23 kg/s.
  • the HC stream is oxidized at a temperature of 1000 °C and a pressure of 1.5 bara.
  • the gas stream obtained in unit 7 is passed via line 9 into quenching unit 10.
  • the quenching unit 10 the gas stream is cooled with water to a temperature of 60 °C, and the water is withdrawn from the quenching unit via line 11.
  • This gas stream is subsequently contacted at a temperature of 60 °C and a pressure of 1.2 bara in an absorption/regeneration unit 13 with Cansolv SO 2 solvent that selectively absorbs sulphur dioxide to obtain a sulphur dioxide-enriched absorption solvent and a gas stream.
  • the sulphur dioxide-enriched absorption solvent is then regenerated and sulphur dioxide-enriched gas stream thereby obtained is separated from the absorption solvent and passed via line 15 to the catalyst and sulphur separation unit 5.
  • the gas streams are reacted with sulphur oxide at a temperature of 280 °C and a pressure of 1.4 bara with a Claus process catalyst which comprises activated alumina. Sulphur and steam are withdrawn from the catalyst unit via line 16.
  • the molar ratio of hydrogen sulphide to sulphur dioxide in unit 5 is 2:1
  • the hydrogen sulphide-lean gas stream (tail gas) so obtained is passed via line 17 to hydrogenation unit 18 where the gas stream is subsequently contacted at a temperature of 320 °C and a pressure of 1.3 bara with hydrogen as a reducing agent and a SCOT catalyst.
  • the gas stream obtained in hydrogenation unit 18 is passed via line 20 into quenching unit 21. In the quenching unit 21 the gas stream is cooled with water to a temperature of
  • absorption/regeneration unit 24 which is operated at a temperature of 30 °C and a pressure of 1.2 bara.
  • absorption/regeneration unit 24 hydrogen
  • sulphide is selectively absorbed by means of MDEA to obtain a hydrogen sulphide-enriched absorption solvent and a hydrogen sulphide lean gas stream.
  • the hydrogen sulphide-enriched absorption solvent is then regenerated and the hydrogen sulphide-enriched gas stream thereby obtained is recycled to the oxidation unit 2.
  • the gas stream which is lean in sulphur-containing contaminants is recovered via line 25.
  • Said gas stream comprises 100 ppm hydrogen sulphide, 25 % (v/v) carbon dioxide, 65 % (v/v) nitrogen, 20 ppmv carbonyl sulphide (COS), 0 ppmv mercaptans, 0 ppmv carbon disulphide, and 0 ppmv sulphur dioxide .
  • Example 1 A similar process as described in Example 1 was carried out, except that no use is made of an integrated units 7, 10 and 13 wherein a residual hydrocarbon product is co-processed.
  • the oxidation and heat recovery unit 2 is operated at a temperature of 1040 °C, a pressure of 1.5 bara, and a molar ratio of hydrogen sulphide to oxide of 2:1.
  • the gas stream so obtained gas is reacted in the catalyst and sulphur separation unit 5 with sulphur oxide at a temperature of 280 °C and a pressure of 1.4 bara.
  • the hydrogenation unit 18 is operated at a temperature of 320 °C and a pressure of 1.1 bara.
  • eventually obtained from the absorption/regeneration unit 24 comprises 200 ppm hydrogen sulphide, 30 % (v/v) carbon dioxide, 65 % (v/v) nitrogen, 20 ppmv carbonyl sulphide (COS), 0 ppmv mercaptans, 0 ppmv carbon disulphide, and 0 ppmv sulphur dioxide.
  • COS ppmv carbonyl sulphide
  • Example 1 constitutes an improvement in terms of efficient removal of sulphur-containing contaminants when compared to comparative Example 2.

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Abstract

A process for removing contaminants, including hydrogen sulphide, from a gas stream, comprising the steps of subjecting the gas stream to a Claus Process; subjecting the tail gas obtained in said Claus Process to a SCOT process; recycling the hydrogen sulphide-enriched gas obtained in said SCOT process to the gas stream for the Claus Porcess; subjecting a sulphur-containing residual hydrocarbon product to oxidation to obtain a gas stream which comprises sulphur dioxide; cooling and quenching said gas stream which comprises sulphur dioxide; absorbing said sulphur dioxide with an absorption solvent to obtain a sulphur dioxide-enriched absorption solvent which is regenerated and the sulphur dioxide - enriched gas stream produced therein is used as sulphur dioxide source for Claus Process.

Description

PROCESS FOR REMOVING SULPHUR-CONTAINING CONTAMINANTS FROM
A GAS STREAM
Field of the invention
The present invention relates to a process for removing sulphur-containing contaminants, including hydrogen sulphide, from a gas stream.
Background of the invention
The removal of sulphur-containing compounds from gas streams comprising such compounds has always been of considerable importance in the past and is even more so today in view of continuously tightening environmental regulations. This holds for hydrogen sulphide-containing gases that have become available in for example oil refineries and combustion gases obtained from a coke- oven. Sulphur contaminants in such gases include apart from hydrogen sulphide, carbonyl sulphide, carbon
disulphide and mercaptans . Considerable effort has been spent to find effective and cost-efficient means to remove these undesired compounds. In addition, such gas streams may also contain varying amounts of carbon dioxide which depending on the use of the gas stream often have to be removed at least partly.
One well-know method that is used to treat certain process streams that contain hydrogen sulphide to recover elemental sulphur is the Claus process. The Claus process is a two-step process that includes a burner (oxidation) step followed by a catalytic step wherein use is made of one or more catalytic stages. In the oxidation step, the hydrogen sulphide of a feed stream is partially oxidized by combustion with oxygen to form a gas containing sulphur dioxide. The unreacted hydrogen sulphide and the formed sulphur dioxide contained in the combustion gas can undergo the Claus reaction whereby they are reacted to form elemental sulphur. Further in the Claus process, unreacted hydrogen sulphide and sulphur dioxide in the combustion gas are catalytically reacted in accordance with the Claus reaction by passing the combustion gas over a Claus catalyst which provides for a lower Claus reaction temperature. While the Claus process is very effective at providing for the recovery of a major portion of the sulphur in its feed stream, it still contains appreciable amounts of sulphur compounds such as hydrogen sulphide, carbonyl sulphide and sulphur dioxide. This does not only apply to sulphur recovery with a two- bed catalytic Claus plant, but also to Claus plants with three or more catalytic beds. The tail gas from a Claus process therefore is usually subjected to a hydrogenation treatment to further reduce the amounts of sulphur dioxide, COS, CS2, and mercaptans by converting them into hydrogen sulphide, followed by a treatment wherein use is made of an amine that selectively absorbs hydrogen sulphide. Upon regeneration of the hydrogen sulphide-rich amine stream a gas stream enriched in hydrogen sulphide can be recovered which can subsequently be recycled to the Claus unit. The combination of the hydrogenation and amine treatments can be a so-called SCOT process. The tail gas subjected to such a SCOT process still contains noticeable amounts of hydrogen sulphide (in the order of 100 ppm sulphur) . For that reason the tail gas will need to be oxidized in an incinerator before it can be
discarded into the air as vent gas or used for other purposes.
Hence, there is an ongoing need for improved sulphur recovery processes that provide for high sulphur recovery and better operating efficiencies, preferably with lower capital costs. With increasingly more stringent sulphur emission standards, there is also a need for sulphur recovery processes that provide for even greater sulphur recoveries from process streams containing sulphur compounds than are provided by conventional sulphur recovery systems.
Summary of the invention
It has now been found that an improved removal of sulphur-containing contaminants from a gas stream can be established, as well as a decrease in hardware and an increase in energy efficiency when a Claus process is part of a particularly integrated multi-step process for removing sulphur-containing contaminants from a gas stream.
Accordingly, the present invention relates to a process for removing contaminants, including hydrogen sulphide, from a gas stream comprising the steps of:
(a) subjecting the gas stream to an oxidation treatment ;
(b) extracting heat from the gas stream as obtained in step (a) ;
(c) reacting hydrogen sulphide present in the cooled gas stream as obtained in step (b) with sulphur dioxide at elevated temperature and in the presence of a catalyst to obtain a gas stream which comprises sulphur and water;
(d) separating sulphur from the gas stream
obtained in step (c) , thereby obtaining a hydrogen sulphide lean gas stream;
(e) subjecting a sulphur-containing residual hydrocarbon product to an oxidation treatment to obtain a gas stream which comprises sulphur dioxide; (f) extracting heat from the gas stream which comprises sulphur dioxide as obtained in step (e) ;
(g) subjecting at least part of the cooled gas stream as obtained in step (f) to a quench process; (h) contacting at least part of the gas stream as obtained in step (g) with an absorption solvent that absorbs sulphur dioxide to obtain a sulphur dioxide- enriched absorption solvent and a sulphur dioxide- depleted gas stream;
(i) removing sulphur dioxide from at least part of the sulphur dioxide-enriched adsorption solvent as obtained in step (h) to obtain a sulphur dioxide- depleted absorption solvent and a sulphur dioxide- enriched gas stream;
(j) passing at least part of the sulphur dioxide- enriched gas stream as obtained in step (i) to step (c) ;
(k) contacting at least part of the hydrogen sulphide lean gas stream as obtained in step (d) with a reducing agent and a catalyst to obtain an hydrogen sulphide-enriched gas stream;
(1) extracting heat from the hydrogen sulphide- enriched gas stream as obtained in step (k);
(m) subjecting at least part of the cooled gas stream as obtained in step (1) to a quench process;
(n) contacting at least part of the hydrogen sulphide-enriched gas stream as obtained in step (m) with an absorption solvent that absorbs hydrogen sulphide to obtain a hydrogen sulphide-enriched absorption solvent and a hydrogen sulphide-depleted gas stream;
(o) removing hydrogen sulphide from at least part of the hydrogen sulphide-enriched absorption solvent as obtained in step (n) to obtain a hydrogen
sulphide-depleted absorption solvent and a hydrogen sulphide-enriched gas stream; and
(p) recycling at least part of the hydrogen sulphide-enriched gas stream as obtained in step (o) to step (a) .
In accordance with the present invention gas streams can be obtained that contain such small amounts of sulphur-containing contaminants that they can
advantageously directly be vented into the air or used for different purposes.
Detailed description of the invention
The present invention relates to a process for removing sulphur-containing contaminants, including hydrogen sulphide, from an acid gas stream. The acid gas stream to be treated in accordance with the present invention can be any gas stream comprising sulphur- containing contaminants. The process according to the invention is especially suitable for gas streams
comprising sulphur-containing contaminants and optionally also amounts of carbon dioxide. Suitably the total gas stream to be treated comprises in the range of from 40 to 100 vol% hydrogen sulphide and from 0 to 60 vol% carbon dioxide, based on the total gas stream. Preferably, the gas stream to be treated comprises from 55 to 100 vol% hydrogen sulphide and from 0 to 45 vol% carbon dioxide, based on the total gas stream.
In step (a) the oxidation treatment is carried at a temperature in the range of from 980-2000 °C, preferably in the range of from 1090-1540 °C, and a pressure in the range of from 1.29-2.05 bara, preferably in the range of from 1.56-2.05 bara. Preferably, the molar ratio of hydrogen sulphide to oxide in step (a) is in the range of from 2:1-3:1.
Step (a) can suitably be carried out in a burner. Prior to such an oxidation treatment in step (a) the gas stream can suitably be subjected to an enrichment
treatment. In such an enrichment treatment carbon dioxide and hydrocarbons can be removed from the gas stream, whereas hydrogen sulphide can be retained in the gas stream which is to be subjected to (a) by using a
particular absorbent that selectively absorbs hydrogen sulphide. Preferably, the gas stream to be subjected to the oxidation treatment in step (a) contains hydrogen sulphide in an amount in the range of 45-100 mole %, based on total gas stream.
In step (b) heat is extracted from the gas stream as obtained in step (a) . This can suitably be done by cooling the gas stream in a two-step heat recovery unit to a temperature range 163-177 °C, preferable to a range between 168-174 °C. In the first step, a Waste Heat Boiler can suitably be used to generate high to medium pressure steam by cooling the gases to 260-370 °C, preferable to 315-343 °C. In the second step low pressure steam can suitably be generated by cooling the gas stream to a temperature range 163-177 °C, preferable to a range between 168-174 °C. It is believed that at these
temperatures the sulphur dew point will be reached and the heat exchanger should be designed for removal of condensed liquid sulphur.
In step (c) use can be made of one or more catalytic stages, whereby after each respective catalytic stage sulphur can be separated from the gas stream as described in step (d) . In step (d) the separation of sulphur from the gas stream can suitably be carried out by means of a sulphur condensation unit.
In step (c) hydrogen sulphide present in the cooled gas stream as obtained in step (b) can be reacted with sulphur dioxide at elevated temperature in a first catalytic stage to obtain a gas stream which comprises sulphur and water. Suitably step (c) comprises a
catalytic step of a Claus process as described
hereinabove. Suitably, the first catalytic stage is carried out in a catalytic zone where hydrogen sulphide reacts with sulphur dioxide to produce more sulphur.
Suitably, the reaction in the first catalytic stage is carried out with a Claus conversion catalyst at a
temperature in the range of from 204-371 °C, preferably in the range of from 260-343 °C, and a pressure in the range of from 1-2 bara, preferably in the range of from 1.4-1.7 bara. Suitably, a second and a third catalytic stage can be used in step (c) in which stages use is made of a Claus conversion catalyst. Suitably, in such a second and third catalytic stage the reaction is carried out at a temperature which is 5 to 20 °C above the sulphur dew point, preferable at a temperature which is 10 to 15 °C above the sulphur dew point, and a pressure in the range of from 1-2 bara, preferably in the range of from 1.4-1.7 bara. Preferably, the molar ratio of
hydrogen sulphide to sulphur dioxide in step (c) is in the range of from 2:1-3:1.
Sulphur condensation units can suitably be applied after each catalytic stage in step (c) , which
condensation units can suitably be operated at
temperature in the range of from range 160-171 °C, preferable in the range of from 163-168 °C. The remaining gases as obtained after condensation of sulphur from the gases leaving the final catalytic zone are usually referred to as "Claus tail gases". These gases contain nitrogen, water vapour, some hydrogen sulphide, sulphur dioxide and usually also carbon
dioxide, carbon monoxide, carbonyl sulphide and carbon disulphide, hydrogen, and small amounts of elemental sulphur .
A suitable Claus catalyst has for instance been described in European patent application No. 0038741, which catalyst substantially consists of titanium oxide. Other suitable catalysts include activated alumina and bauxite catalysts.
In step (d) sulphur is separated from the gas stream obtained in step (c) , thereby obtaining a hydrogen sulphide-lean gas stream. To that end the gas stream as obtained in step (c) can be cooled below the sulphur dew point to condense and subsequently most of the sulphur obtained can be separated from the gas stream. Hence, step (d) can suitably be carried out by cooling the effluent obtained in step (c) to condense and separate sulphur, thereby obtaining the hydrogen sulphide-depleted gas stream.
In step (e) a sulphur-containing residual hydrocarbon product is subjected to an oxidation treatment to obtain a gas stream which comprises sulphur dioxide. In step (e) the oxidation treatment is preferably carried at a temperature in the range of from 538-1038 °C, preferably in the range of from 648-982 °C, and a pressure in the range of from 1-2 bara, preferably in the range of from 1.4-1.7 bara .
In step (e) any sulphur-containing residual
hydrocarbon product can be used. The sulphur-containing residual hydrocarbon product to be used in step (e) is preferably a product from a thermal gasoil unit having a V50 (viscosity at 50 °C) in the range of from 30-50 cSt, a product from a catalytic cracking unit, suitably in slurry form, having a V50 in the range of from 20-50 cSt, or a heavy residue containing up to 10 wt% organic sulphur, based on total heavy residue. More preferably, the residual hydrocarbon product comprises a product from a thermal gasoil unit having a V50 in the range of from 35-45 cSt. The integration of step (e) advantageously ensures that the size of the Claus unit to be used can be reduced or that the capacity of the Claus unit can be increased .
In step (f) heat is extracted from the gas stream which comprises sulphur dioxide as obtained in step (e) .
The heat extraction in step (f) can be carried out in a similar way as the heat extraction in step (b) as
described hereinbefore.
In step (g) at least part of the cooled sulphur dioxide-enriched gas stream as obtained in step (f) is subjected to a quenching process before is contacted with the absorption solvent in step (h) . In such a quenching process the respective gas streams are suitably cooled by means of water quenching. Preferably, the entire cooled sulphur dioxide-enriched gas stream as obtained in step
(f) is subjected to the quenching process before is contacted with the absorption solvent in step (h) .
Suitably, these gas streams are cooled to a temperature in the range of from 40-60 °C in the quenching process. In step (h) at least part of the sulphur dioxide-enriched gas stream as obtained in step (g) is contacted with an absorption solvent that absorbs sulphur dioxide to obtain a sulphur dioxide-enriched absorption solvent and a sulphur dioxide-depleted gas stream.
Preferably, in step (h) use is made of an aqueous solution of the absorption solvent.
Suitably, 10-90 vol.% of the gas stream as obtained in step (g) can be contacted with the absorption solvent in step (h) . Preferably, the entire gas stream as obtained in step (g) is contacted with the absorption solvent in step (h) .
Preferably, the absorption solvent in step (h) comprises water and a water-soluble amine absorbent having at least one amine group with a pKa value greater than about 7 and at least one other amine group with a pKa value less than 6.5, wherein the at least one amine group with a pKa value greater than about 7 irreversibly absorbs sulphur dioxide in salt form to render the amine absorbent non-volatile, and wherein the at least one other amine group with a pKa value less than 6.5
reversibly absorbs sulphur dioxide to saturate the absorption solvent with sulphur dioxide against a partial pressure of sulphur dioxide of no more than 1 atmosphere at 25 °C.
Preferably, the water-soluble amine absorbent is a diamine having the general formula:
R2R5NR1NR3R4
wherein Ri is an alkylene group having 1 to 3 carbon atoms, R2, R3, R and R5 are the same or different and each represent a hydrogen atom, a lower alkyl group having 1 to 8 carbon atoms or a lower hydroxy-alkyl group having 2 to 8 carbon atoms, or any of R2, R3, R and R5 form together with the nitrogen atoms to which they are attached a 6-membered ring.
More preferably, the diamine is selected from the group consisting of N, N ' , N ' - ( trimethyl ) -N- ( 2- hydroxyethyl ) -ethylenediamine ;
N, N, N ' , N ' -tetramethyl-ethylenediamine ;
N, N, N ' , N ' -tetramethyl-diaminomethane ;
Ν,Ν,Ν' ,Ν'-tetrakis- ( 2-hydroxyethyl ) -ethylenediamine ; N, N ' -dimethylpiperazine ;
Ν,Ν,Ν' ,Ν'-tetrakis- ( 2-hydroxyethyl ) -1 , 3-diaminopropane ; N ' , N ' -dimethyl-N, N-bis- ( 2-hydroxyethyl ) -ethylenediamine ; N-methyl N ' - ( 2-hydroxyethyl ) -piperazine ;
N- ( 2-hydroxyethyl ) -piperazine;
N, N ' -bis (2-hydroxyethyl ) -piperazine ;
N-methyl-piperazine ; and piperazine.
It will be understood that the sulphur dioxide- enriched absorption solvent as obtained in step (h) will need to be regenerated in order to ensure that the absorption solvent can be used again in step (h) . For that purpose the sulphur dioxide-enriched absorption solvent as obtained in step (h) will normally be passed to a regeneration unit step (i) where the absorption solvent will be freed from sulphur oxide and the sulphur oxide-depleted absorption solvent so obtained can suitably be recycled to step (h) .
Step (h) can suitably be carried at a temperature in the range of from 20-80 °C, preferably in the range of from 30-60 °C, and a pressure in the range of from 1.1-2 bara, preferably in the range of from 1.4-1.7 bara.
Suitably, use is made in step (h) of an aqueous solution that comprises the absorption solvent in a concentration in the range of from 30-55 w% .
In a particular attractive embodiment of the present invention at least part of the sulphur dioxide-depleted gas stream as obtained in step (h) is contacted with an absorption solvent to absorb carbon dioxide to obtain a carbon dioxide-enriched absorption solvent and a sulphur dioxide-depleted gas stream which is lean in carbon dioxide, and carbon dioxide is removed from at least part of the carbon dioxide-enriched adsorption solvent to obtain a carbon dioxide-depleted absorption solvent and a carbon dioxide-enriched gas stream. Preferably, the entire sulphur dioxide-depleted gas stream as obtained in step (h) is contacted with an absorption solvent to absorb carbon dioxide to obtain a carbon dioxide-enriched absorption solvent and a sulphur dioxide-depleted gas stream which is lean in carbon dioxide, and carbon dioxide is removed from at least part of the carbon dioxide-enriched adsorption solvent to obtain a carbon dioxide-depleted absorption solvent and a carbon dioxide-enriched gas stream.
The sulphur dioxide-depleted gas stream as obtained in step (h) is highly attractive since it is lean in respect of sulphur-containing contaminants. Suitably, the sulphur dioxide-depleted gas stream as obtained in step (h) contains no hydrogen sulphide and less than 50 ppmv sulphur dioxide. Preferably, said gas stream contains less than 30 ppmv sulphur dioxide.
In step (i) sulphur dioxide is removed from at least part of the sulphur dioxide-enriched adsorption solvent as obtained in step (h) to obtain a sulphur dioxide- depleted absorption solvent and a sulphur dioxide- enriched gas stream. Suitably, at least part of the sulphur dioxide-depleted absorption solvent as obtained in step (i) is recycled to step (h) . Preferably, the entire sulphur dioxide-depleted absorption solvent as obtained in step (i) is recycled to step (h) .
Step (i) can suitably be carried at a temperature in the range of from 110-150 °C, preferably in the range of from 120-140 °C, and a pressure in the range of from 1.1-1.9 bara, preferably in the range of from 1.2-1.7 bara .
In step (j) at least part of the sulphur dioxide- enriched gas stream as obtained in step (i) is passed to step (c) . Preferably, the entire sulphur dioxide- enriched gas stream as obtained in step (i) is passed to step (c) .
In step (k), at least part of the hydrogen sulphide lean gas stream as obtained in step (d) is subjected to a hydrogenation treatment to obtain a hydrogen sulphide- enriched gas stream. In step (k) the amounts of sulphur dioxide, COS, CS2, and mercaptants are further reduced by converting these contaminants into hydrogen sulphide, Preferably, in step (k) the entire hydrogen sulphide lean gas stream as obtained in step (d) is subjected to the hydrogenation treatment to obtain a hydrogen sulphide- enriched gas stream. In step (k) suitably use is made of a reducing agent and a catalyst. Step (k) can suitably be carried out at a temperature in the range of from
200-400 °C and a pressure in the range of from 1.1-2 bara. Preferably, step (k) is carried out at a
temperature in the range of from 240-350 °C and a
pressure in the range of from 1.2-1.7 bara. The reducing agent to be used in step (g) is hydrogen. Preferably, this hydrogen is produced in the oxidizing burner in step
(a) . Suitable the hydrogen is present in an amount of 1-5 mole %, based on total gas stream.
In step (1) heat is extracted from the hydrogen sulphide-enriched gas stream as obtained in step (k) . The heat extraction in step (1) can be carried out in a similar way as the heat extraction in step (b) as
described hereinbefore. In step (m) at least part of the cooled hydrogen sulphide-enriched gas stream as obtained in step (1) is subjected to a quenching process. The quenching process in step (m) can be carried out in a similar way as the quenching process in step (g) as described hereinbefore.
In step (n) , at least part of hydrogen-sulphide- enriched gas stream as obtained in step (m) is contacted with an absorption solvent that absorbs hydrogen sulphide to obtain a hydrogen sulphide-enriched absorption solvent and a hydrogen sulphide-depleted gas stream. Suitably, at least part of the hydrogen sulphide-enriched gas stream as obtained in step (1) is subjected to a quenching treatment before it is contacted with the absorption solvent in step (n) . In such a quenching step the
respective gas streams are suitably cooled by means of water quenching. Preferably, the entire gas stream which comprises sulphur dioxide as obtained in step (1) is subjected to the quenching treatment before it is
contacted with the absorption solvent in step (n) .
Suitably, the gas stream is cooled to a temperature in the range of from 40-60 °C in the quenching step.
Preferably, the entire gas stream obtained from the quenching step is contacted with the absorption solvent in step (n) . Suitably, the absorption solvent in step (m) comprises water, and an amine. Additionally, a physical solvent can be present. Preferably, the physical solvent comprises sulfolane.
Suitable amines to be used in step (m) include primary, secondary and/or tertiary amines, especially amines that are derived of ethanolamine, especially monoethanol amine (MEA) , diethanolamine (DEA) ,
triethanolamine (TEA) , diisopropanolamine (DIPA) and methyldiethanolamine (MDEA) or mixtures thereof. A preferred amine is a secondary or tertiary amine, preferably an amine compound derived from ethanol amine, more especially DIPA, DEA, MMEA (monomethyl- ethanolamine) , MDEA, or DEMEA (diethyl- monoethanolamine ) , preferably DIPA or MDEA.
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 mixtures of dialkylethers of polyethylene glycols or mixtures thereof. The preferred physical solvent is sulfolane.
Suitably, step (n) is carried out at a temperature in the range of from 20-60 °C, preferably at a temperature of at least 25 °C, more preferably in the range of from
25-50 °C, still more preferably in the range of from 25-35 °C. Step (m) is suitably carried out at a pressure in the range of from 1.1 - 1.5 bara, preferably in the range of from 1.1-1.5 bara, more preferably in the range of from 1.1-1.4 bara.
The gas stream obtained in step (n) is attractively depleted of hydrogen sulphide and various other sulphur- containing contaminants. The concentration of hydrogen sulphide in the gas stream obtained in step (n) is suitably less than 200 ppmv, preferably less than 100 ppmv .
In step (n) , the hydrogen sulphide-enriched
absorption liquid will also comprise carbon dioxide and other sulphur compounds such as carbonyl sulphides and carbon disulphide.
In step (o) hydrogen sulphide will be removed from at least part of the hydrogen sulphide-enriched absorption solvent as obtained in step (n) to obtain a hydrogen sulphide-depleted absorption solvent and a hydrogen sulphide-enriched gas stream. Hence, step (o) suitably comprises the regeneration of the sulphur compounds- enriched absorption solvent. In step (o) the sulphur compounds-enriched absorption solvent is suitably contacted with regeneration gas and/or heated and can be depressurised, thereby transferring at least part of the contaminants to the regeneration gas. Typically, regeneration takes place at relatively low pressure and high temperature. The regeneration in step (o) is suitably carried out by heating in a regenerator at a relatively high temperature, suitably in the range of from 110-160 °C. The heating is preferably carried out with steam or hot oil. Alternatively, a direct fired reboiler can be applied, if desired. Suitably,
regeneration is carried out at a pressure in the range of from 1.1-1.9 bara. After regeneration, regenerated absorption solvent (i.e. a hydrogen sulphide-depleted absorption solvent) is obtained and a regeneration gas stream enriched with contaminants such as hydrogen sulphide and carbon dioxide. Suitably, at least part of the hydrogen sulphide-depleted absorption solvent as obtained in step (o) is recycled to step (n) .
Preferably, the entire hydrogen sulphide-depleted absorption solvent as obtained in step (o) is recycled to step (n) . Suitably the regenerated absorption solvent is heat exchanged with contaminants enriched absorption solvent to use the heat elsewhere. Suitably, the
enriched regeneration gas stream in sent to a sulphur recovery unit.
In step (p) at least part of the hydrogen sulphide- enriched gas stream as obtained in step (o) is recycled to step (a) . Preferably, in step (p) the entire hydrogen sulphide-enriched gas stream as obtained in step (o) is recycled to step (a) .
One embodiment of the present invention is
illustrated in Figure 1.
In Figure 1, a gas stream comprising sulphur- containing contaminants, including hydrogen sulphide is led via line 1 to an oxidation and heat recovery unit 2 (e.g. a combined burner and heat recovery unit) wherein the gas stream is oxidized and cooled while producing steam which is removed via line 3. Liquid sulphur which is condensed at the low temperature range is also removed via line 3. From unit 2 the gas stream obtained is passed via line 4 to a catalyst and sulphur separation unit 5.
In oxidation and heat recovery unit 7 a residual hydrocarbon product, introduced via line 6, is subjected to an oxidation treatment to obtain a gas stream which comprises sulphur dioxide. Heat recovered in the
oxidation and heat recovery unit 7 is then removed via line 8. The gas stream obtained in oxidation and heat recovery unit 7 is passed via line 9 into a quenching unit 10. The quenching medium, e.g. water, can be
withdrawn from the quenching unit 10 via line 11. The gas stream obtained in the quenching unit 10 is subsequently passed via line 12 to absorption/regeneration unit 13 where it is contacted with an absorption solvent that absorbs sulphur dioxide to obtain a sulphur dioxide- enriched absorption solvent and a sulphur dioxide- depleted gas stream. The sulphur dioxide-enriched
absorption solvent is then regenerated and sulphur dioxide-enriched gas stream thereby obtained is separated from the regenerated absorption solvent and send via line 15 to the catalytic and sulphur separation unit 5.
Regenerated solvent is removed via line 14. In unit 5 the hydrogen sulphide in the gas stream is reacted with sulphur dioxide in the presence of a
catalyst to obtain a gas stream which comprises sulphur and water, whereby sulphur is withdrawn via line 16. Low pressure steam generated in sulphur condensers in unit 5 can also be removed via line 16. The hydrogen sulphide- lean gas stream (tail gas) so obtained is passed via line 17 into hydrogenation unit 18 to obtain by means of a reducing agent and a catalyst a hydrogen sulphide- enriched gas stream. Steam produced in the subsequent cooling stages is removed via line 19. The hydrogen sulphide-enriched gas stream so obtained is passed via line 20 to a quenching unit 21. The quenching medium, e.g. water, can be withdrawn from the quenching unit 21 via line 22. The gas stream obtained in the quenching unit 21 is subsequently passed via line 23 to
absorption/regeneration unit 24 where it is contacted with an absorption solvent that absorbs hydrogen sulphide to obtain a hydrogen sulphide-enriched absorption solvent and a hydrogen sulphide-depleted gas stream. The hydrogen sulphide-enriched absorption solvent is then regenerated and hydrogen sulphide-enriched gas stream thereby
obtained is separated from the absorption solvent and passes via line 26 to the oxidation unit 2. The treated gas stream which is lean in sulphur-containing
contaminants is recovered via line 25.
The invention is illustrated using the following non- limiting Examples.
Example 1 (according to the invention)
In a process as described in Figure 1, an acid gas comprising 60 % (v/v) hydrogen sulphide, 40 % (v/v) carbon dioxide, 0 % (v/v) sulphur dioxide, 50 ppmv carbonyl sulphide (COS), 200 ppmv mercaptans and 20 ppmv carbon disulphide is routed via line 1 to an oxidation and heat recovery unit 2 with a flow rate of 6.74 Nm3/s. In an oxidation and heat recovery unit 2 the acid gas is oxidized at a temperature of 980 °C and a pressure of 1.5 bara. The molar ratio of hydrogen sulphide to oxide in unit 2 is 2:1. The gas stream so obtained gas is passed via line 4 to catalyst and sulphur separation unit 5. A sulphur-containing residual hydrocarbon product is routed via line 6 to an oxidation and heat recovery unit 7 with a flow rate of 7.23 kg/s. In unit 7 the HC stream is oxidized at a temperature of 1000 °C and a pressure of 1.5 bara. The gas stream obtained in unit 7 is passed via line 9 into quenching unit 10. In the quenching unit 10 the gas stream is cooled with water to a temperature of 60 °C, and the water is withdrawn from the quenching unit via line 11. This gas stream is subsequently contacted at a temperature of 60 °C and a pressure of 1.2 bara in an absorption/regeneration unit 13 with Cansolv SO2 solvent that selectively absorbs sulphur dioxide to obtain a sulphur dioxide-enriched absorption solvent and a gas stream. The sulphur dioxide-enriched absorption solvent is then regenerated and sulphur dioxide-enriched gas stream thereby obtained is separated from the absorption solvent and passed via line 15 to the catalyst and sulphur separation unit 5. In unit 5 the gas streams are reacted with sulphur oxide at a temperature of 280 °C and a pressure of 1.4 bara with a Claus process catalyst which comprises activated alumina. Sulphur and steam are withdrawn from the catalyst unit via line 16. The molar ratio of hydrogen sulphide to sulphur dioxide in unit 5 is 2:1 The hydrogen sulphide-lean gas stream (tail gas) so obtained is passed via line 17 to hydrogenation unit 18 where the gas stream is subsequently contacted at a temperature of 320 °C and a pressure of 1.3 bara with hydrogen as a reducing agent and a SCOT catalyst. The gas stream obtained in hydrogenation unit 18 is passed via line 20 into quenching unit 21. In the quenching unit 21 the gas stream is cooled with water to a temperature of
35°C, and the water is withdrawn from the quenching unit via line 22. The gas stream so obtained is passed via line 23 to an absorption/regeneration unit 24 which is operated at a temperature of 30 °C and a pressure of 1.2 bara. In absorption/regeneration unit 24 hydrogen
sulphide is selectively absorbed by means of MDEA to obtain a hydrogen sulphide-enriched absorption solvent and a hydrogen sulphide lean gas stream. The hydrogen sulphide-enriched absorption solvent is then regenerated and the hydrogen sulphide-enriched gas stream thereby obtained is recycled to the oxidation unit 2. The gas stream which is lean in sulphur-containing contaminants is recovered via line 25. Said gas stream comprises 100 ppm hydrogen sulphide, 25 % (v/v) carbon dioxide, 65 % (v/v) nitrogen, 20 ppmv carbonyl sulphide (COS), 0 ppmv mercaptans, 0 ppmv carbon disulphide, and 0 ppmv sulphur dioxide .
Example 2 (comparative Example)
A similar process as described in Example 1 was carried out, except that no use is made of an integrated units 7, 10 and 13 wherein a residual hydrocarbon product is co-processed. The oxidation and heat recovery unit 2 is operated at a temperature of 1040 °C, a pressure of 1.5 bara, and a molar ratio of hydrogen sulphide to oxide of 2:1. The gas stream so obtained gas is reacted in the catalyst and sulphur separation unit 5 with sulphur oxide at a temperature of 280 °C and a pressure of 1.4 bara. The hydrogenation unit 18 is operated at a temperature of 320 °C and a pressure of 1.1 bara. The gas stream
eventually obtained from the absorption/regeneration unit 24 comprises 200 ppm hydrogen sulphide, 30 % (v/v) carbon dioxide, 65 % (v/v) nitrogen, 20 ppmv carbonyl sulphide (COS), 0 ppmv mercaptans, 0 ppmv carbon disulphide, and 0 ppmv sulphur dioxide.
From the above, it will be clear that the process in accordance with the present invention (Example 1) constitutes an improvement in terms of efficient removal of sulphur-containing contaminants when compared to comparative Example 2.

Claims

C L A I M S
1. A process for removing contaminants, including hydrogen sulphide, from a gas stream comprising the steps of:
(a) subjecting the gas stream to an oxidation treatment ;
(b) extracting heat from the gas stream as
obtained in step (a) ;
(c) reacting hydrogen sulphide present in the cooled gas stream as obtained in step (b) with sulphur dioxide at elevated temperature and in the presence of a catalyst to obtain a gas stream which comprises sulphur and water;
(d) separating sulphur from the gas stream
obtained in step (c) , thereby obtaining a hydrogen sulphide lean gas stream;
(e) subjecting a sulphur-containing residual hydrocarbon product to an oxidation treatment to obtain a gas stream which comprises sulphur dioxide;
(f) extracting heat from the gas stream which comprises sulphur dioxide as obtained in step (e) ;
(g) subjecting at least part of the cooled gas stream as obtained in step (f) to a quench process;
(h) contacting at least part of the gas stream as obtained in step (g) with an absorption solvent that absorbs sulphur dioxide to obtain a sulphur dioxide- enriched absorption solvent and a sulphur dioxide- depleted gas stream;
(i) removing sulphur dioxide from at least part of the sulphur dioxide-enriched adsorption solvent as obtained in step (h) to obtain a sulphur dioxide- depleted absorption solvent and a sulphur dioxide- enriched gas stream;
(j) passing at least part of the sulphur dioxide- enriched gas stream as obtained in step (i) to step (c);
(k) contacting at least part of the hydrogen sulphide lean gas stream as obtained in step (d) with a reducing agent and a catalyst to obtain an hydrogen sulphide-enriched gas stream;
(1) extracting heat from the hydrogen sulphide- enriched gas stream as obtained in step (k);
(m) subjecting at least part of the cooled gas stream as obtained in step (1) to a quench process;
(n) contacting at least part of the hydrogen sulphide-enriched gas stream as obtained in step (m) with an absorption solvent that absorbs hydrogen sulphide to obtain a hydrogen sulphide-enriched absorption solvent and a hydrogen sulphide-depleted gas stream;
(o) removing hydrogen sulphide from at least part of the hydrogen sulphide-enriched absorption solvent as obtained in step (n) to obtain a hydrogen
sulphide-depleted absorption solvent and a hydrogen sulphide-enriched gas stream; and
(p) recycling at least part of the hydrogen sulphide-enriched gas stream as obtained in step (o) to step (a) .
2. A process according to claim 1, wherein at least part of the sulphur dioxide-depleted absorption solvent as obtained in step (i) is recycled to step (h) .
3. A process according to claim 1 or 2, wherein the entire hydrogen sulphide-enriched gas stream as
obtained in step (o) is recycled to step (a) .
4. A process according to any one of claims 1-3, wherein the entire sulphur dioxide-enriched gas stream as obtained in step (i) is passed to step (c) .
5. A process according to any one of claims 1-4, wherein the gas stream has been subjected to an hydrogen
sulphide enrichment treatment prior to the oxidation treatment in step (a) .
6. A process according to any one of claims 1-5, wherein at least part of the sulphur dioxide-depleted gas stream as obtained in step (h) is contacted with an absorption solvent to absorb carbon dioxide to obtain a carbon dioxide-enriched absorption solvent and a carbon
dioxide-depleted gas stream, and carbon dioxide is removed from at least part of the carbon dioxide- enriched absorption solvent to obtain a carbon dioxide- depleted absorption solvent and a carbon dioxide- enriched gas stream.
7. A process according to any one of claims 1-6, wherein step (d) is carried out by cooling the effluent obtained in step (c) to condense and separate sulphur, thereby obtaining the hydrogen sulphide-depleted gas stream.
8. A process according to any one of claims 1-7, wherein the sulphur-containing residual hydrocarbon product in step (e) is a product from a thermal gasoil unit having a V50 (viscosity at 50 °C) in the range of from 30-50 cSt, a product from a catalytic cracking unit, suitably in slurry form, having a V50 in the range of from 20-50 cSt, or a heavy residue containing up to 10 wt% organic sulphur, based on total heavy residue.
9. A process according to any one of claims 1-8, wherein the entire gaseous stream as obtained in step (g) is contacted with the absorption solvent in step (h) .
10. A process according to any one of claims 1-9, wherein the gas stream to be subjected to the oxidation
treatment in step (a) contains hydrogen sulphide in an amount in the range of 40-100 mole %, based on total gaseous stream.
11. A process according to any one of claims 1-10, wherein the molar ratio of hydrogen sulphide to sulphur dioxide in step (c) is in the range of from 2:1-3:1.
12. A process according to any one of claims 1-11, wherein the absorption solvent in step (h) comprises water and a water-soluble amine absorbent having at least one amine group with a pKa value greater than about 7 and at least one other amine group with a pKa value less than 6.5, wherein the at least one amine group with a pKa value greater than about 7 irreversibly absorbs sulphur dioxide in salt form to render the amine absorbent non-volatile, and wherein the at least one other amine group with a pKa value less than 6.5
reversibly absorbs sulphur dioxide to saturate the absorption solvent with sulphur dioxide against a partial pressure of sulphur dioxide of no more than about 1 atmosphere at 25 °C.
13. A process according to claim 12, wherein the amine absorbent is a diamine having the general formula:
R2R5NR1NR3R4
wherein Ri is an alkylene group having 1 to 3 carbon atoms, R2, R3, R and R5 are the same or different and each represent a hydrogen atom, a lower alkyl group having 1 to 8 carbon atoms or a lower hydroxy-alkyl group having 2 to 8 carbon atoms, or any of R2, R3, R and R5 form together with the nitrogen atoms to which they are attached a 6-membered ring.
14. A process according to claim 13, wherein the diamine is selected from the group consisting of Ν,Ν',Ν'- (trimethyl) -N- ( 2-hydroxyethyl ) -ethylenediamine ;
N, N, N ' , N ' -tetramethyl-ethylenediamine;
N, N, N ' , N ' -tetramethyl-diaminomethane ;
Ν,Ν,Ν' ,Ν'-tetrakis- (2-hydroxyethyl ) -ethylenediamine ;
N, N ' -dimethylpiperazine ;
Ν,Ν,Ν' ,Ν'-tetrakis- (2-hydroxyethyl ) -1 , 3-diaminopropane ; N ' , N ' -dimethyl-N, N-bis- (2-hydroxyethyl ) -ethylenediamine ; N-methyl N '-( 2-hydroxyethyl ) -piperazine ;
N- (2-hydroxyethyl) -piperazine;
N, N ' -bis (2-hydroxyethyl ) -piperazine ;
N-methyl-piperazine ; and piperazine.
PCT/EP2011/074185 2010-12-31 2011-12-28 Process for removing sulphur-containing contaminants from a gas stream Ceased WO2012089781A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112011372A (en) * 2020-07-27 2020-12-01 中冶南方都市环保工程技术股份有限公司 Blast furnace gas desulfurization circulating system and method based on ultraviolet light

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1344472A (en) * 1971-01-12 1974-01-23 Parsons Co Ralph M Process for reducing sulphur content of effluent gas streams
US4060595A (en) * 1975-07-17 1977-11-29 Metallgesellschaft Aktiengesellschaft Process for recovering elemental sulfur from gases having a high carbon dioxide content and containing sulfur compounds
EP0038741A1 (en) 1980-04-23 1981-10-28 Rhone-Poulenc Chimie Preparation process for catalysts or catalyst supports made of titanium dioxide and its use in the Claus catalysis
US4532119A (en) * 1981-03-13 1985-07-30 Rhone-Poulenc Specialites Chimiques Catalytic desulfurization of industrial waste gases
US6342169B1 (en) * 1997-03-25 2002-01-29 Cansolv Technologies, Inc. Safe storage and transportation of sulfur dioxide
EP1186334A1 (en) * 2000-08-31 2002-03-13 The BOC Group plc Treatment of a gas stream containing hydrogen sulphide

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1344472A (en) * 1971-01-12 1974-01-23 Parsons Co Ralph M Process for reducing sulphur content of effluent gas streams
US4060595A (en) * 1975-07-17 1977-11-29 Metallgesellschaft Aktiengesellschaft Process for recovering elemental sulfur from gases having a high carbon dioxide content and containing sulfur compounds
EP0038741A1 (en) 1980-04-23 1981-10-28 Rhone-Poulenc Chimie Preparation process for catalysts or catalyst supports made of titanium dioxide and its use in the Claus catalysis
US4532119A (en) * 1981-03-13 1985-07-30 Rhone-Poulenc Specialites Chimiques Catalytic desulfurization of industrial waste gases
US6342169B1 (en) * 1997-03-25 2002-01-29 Cansolv Technologies, Inc. Safe storage and transportation of sulfur dioxide
EP1186334A1 (en) * 2000-08-31 2002-03-13 The BOC Group plc Treatment of a gas stream containing hydrogen sulphide

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112011372A (en) * 2020-07-27 2020-12-01 中冶南方都市环保工程技术股份有限公司 Blast furnace gas desulfurization circulating system and method based on ultraviolet light

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