Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G27/00—Refining of hydrocarbon oils in the absence of hydrogen, by oxidation
  • C10G27/04—Refining of hydrocarbon oils in the absence of hydrogen, by oxidation with oxygen or compounds generating oxygen
  • C10G27/06—Refining of hydrocarbon oils in the absence of hydrogen, by oxidation with oxygen or compounds generating oxygen in the presence of alkaline solutions
• • 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
  • B01D53/46—Removing components of defined structure
  • B01D53/48—Sulfur compounds
  • B01D53/50—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
  • B01D53/46—Removing components of defined structure
  • B01D53/48—Sulfur compounds
  • B01D53/52—Hydrogen sulfide
  • B01D53/523—Mixtures of hydrogen sulfide and sulfur oxides
• • 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
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B17/00—Sulfur; Compounds thereof
  • C01B17/48—Sulfur dioxide; Sulfurous acid
  • C01B17/50—Preparation of sulfur dioxide
  • C01B17/508—Preparation of sulfur dioxide by oxidation of sulfur compounds
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G19/00—Refining hydrocarbon oils in the absence of hydrogen, by alkaline treatment
  • C10G19/02—Refining hydrocarbon oils in the absence of hydrogen, by alkaline treatment with aqueous alkaline solutions

Definitions

• This invention relates to an integrated process for treating hydrocarbon disulfides to produce clean hydrocarbon fuels and elemental sulfur.
• Mercaptans are undesirable because of their unpleasant odor and corrosivity and also because they degrade the stability of end-product fuels.
• the liquid disulfides created by conversion of the mercaptans do not have these undesirable characteristics and can be retained in the Merox treated fuels or removed and used elsewhere in the petroleum refinery.
• the Merox process is generally more economical than a catalytic hydrodesulfurization process and achieves much the same result.
• Economic and practical drawbacks associated with hydrodesulfurization processes include additional dedicated facilities to which the disulfide compounds must be transferred, use of expensive and sensitive catalysts and the treatment and disposal of the byproduct sulfur-containing compounds.
• Merox process One proprietary catalytic mercaptan oxidation process widely used in petroleum refineries and natural gas processing plants to remove mercaptans contained in end-products such as LPG, propane, butanes, light naphthas, kerosene and jet fuel by converting them into liquid hydrocarbon disulfides is known as the Merox process. It is an integrated process comprising the mercaptan extraction step in which mercaptans react with an aqueous caustic solution in the presence of a catalyst, to form sodium alkylthiolate, which is then oxidized in a wet air oxidation step to produce disulfides and a regenerated caustic solution which is recycled back to the extraction step.
• the Merox process requires an alkaline environment which, in some versions of the process, is provided by an aqueous solution of sodium hydroxide (NaOH), a strong base, commonly referred to as caustic.
• NaOH sodium hydroxide
• caustic a strong base
• the alkalinity is provided by ammonia, which is a relatively weaker base than sodium hydroxide and must be handled with special care due to its irritant and toxicity properties.
• RSH is a mercaptan and R is an organic group such as a methyl, ethyl, propyl or other hydrocarbon group.
• R is an organic group such as a methyl, ethyl, propyl or other hydrocarbon group.
• the ethyl mercaptan is a mercaptan and R is an organic group such as a methyl, ethyl, propyl or other hydrocarbon group.
• the catalyst used in some versions of the Merox process is a water-soluble liquid and in other versions, the catalyst is impregnated onto charcoal granules.
• the second step is referred to as regeneration and it involves heating and oxidizing the caustic solution leaving the extractor.
• the oxidation results in converting the extracted mercaptans to organic disulfides (RSSR).
• RSSR organic disulfides
• These disulfides are water-insoluble liquids that are separated and decanted from the aqueous caustic solution.
• the regeneration reaction scheme is as follows:
• Merox mercaptan oxidation units are commonly found in refineries and the disulfides generated are blended with the fuel oil and are typically burned as fuel to produce stream or provide other utilities. This use can raise environmental concerns where the combustion gases with sulfur-containing constituents are emitted in the refinery. In some cases, the disulfides are added to an automotive fuel, or retained as part of the fuel blend; however with increasingly stringent fuel sulfur specifications, it is foreseeable that this use may be eliminated entirely.
• the Claus process is a well-established commercial process for recovering elemental sulfur from gaseous hydrogen sulfide found in oil refineries, natural gas processing plants and other industrial facilities.
• the Claus process includes a thermal and a catalytic step.
• one third of the 3 ⁇ 4S is oxidized to S0 2 in a furnace operating at a temperature of about 1000°C. This ensures a stoichiometric reaction for the subsequent catalytic step in which a 2:1 mix of H 2 S and S0 2 passes through a fixed bed of activated alumina or titania-based catalysts maintained at a temperature in the range of from 200°-350°C to produce elemental sulfur and water.
• the problem addressed by the present invention is the need for an economical and effective method for the recovery of a clean, sulfur-free hydrocarbon fuel from liquid disulfides, and particularly the hydrocarbon disulfides produced in the caustic processing of mercaptan- containing hydrocarbon product streams, and specifically the Merox process.
• catalysts disclosed in US 2013/0026072 and US 2013/0028822, which are commonly owned with the present application are particularly useful in the practice of the gaseous oxidation of the hydrocarbon disulfides in the process of this invention.
• the catalyst compositions useful in the oxidative desulfurization of gaseous sulfur-containing hydrocarbons are those that comprise specific amounts and ranges of copper oxide, zinc oxide, aluminum oxide and, optionally, cerium.
• the disclosures of US 2013/0026072 and US 2013/0028822 are incorporated herein by reference.
• FIG. 1 is a simplified schematic illustration of the process
• Fig. 2 is a comparative plot of the percent conversion of dimethyldisulfide (DMDS) for two different catalyst systems with a ratio of 0 2 /S equal to 12; and
• Fig. 3 is a comparative plot of the percent conversion of DMDS for varying ratios of 0 2 /S for the two catalyst systems shown in Fig. 2.
• the integrated process of the invention for treating liquid hydrocarbon disulfide products comprises the following steps:
• step (d) a gaseous desulfurization step in which S0 2 is reacted with hydrogen sulfide to produce elemental sulfur.
• steps (a) and (b) correspond to the conventional Merox process and step (d) corresponds to the conventional Claus process.
• the liquid mercaptan hydrocarbon stream can have a sulfur content of from about 10 to about 60 wt %.
• Addition of the oxidation step (c) between the Merox and Claus processes efficiently converts hydrocarbon disulfides into sulfur dioxide and light hydrocarbon gases and/or liquids which can be used as clean fuel in the refinery.
• the sulfur dioxide generated is sent to the Claus process unit and fully or partially eliminates the need for the conventional thermal hydrogen sulfide conversion step, because there is no need to produce sulfur dioxide from a portion of the 3 ⁇ 4S as in the conventional Claus process to react with the remaining hydrogen sulfide in the production of elemental sulfur.
• the present invention provides an economical and effective method for the recovery of a clean, sulfur-free hydrocarbon fuel from liquid disulfides, including specifically the liquid hydrocarbon disulfides produced in the caustic processing of mercaptan-containing hydrocarbon product streams.
• the disclosed process has widespread applicability to large scale operations such as refineries and gas processing plants where the disulfides can be processed to remove their sulfur constituent and provide an environmentally acceptable clean-burning hydrocarbon fuel.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Biomedical Technology (AREA)
• Environmental & Geological Engineering (AREA)
• Analytical Chemistry (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Catalysts (AREA)
• Treating Waste Gases (AREA)

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• 2014
  • 2014-11-24 US US14/552,222 patent/US9580661B2/en active Active
• 2015
  • 2015-11-02 KR KR1020177017090A patent/KR102470507B1/ko active Active
  • 2015-11-02 EP EP15797736.4A patent/EP3223932B1/en active Active
  • 2015-11-02 WO PCT/US2015/058547 patent/WO2016085619A1/en not_active Ceased
  • 2015-11-02 CN CN201580054425.3A patent/CN107108209B/zh not_active Expired - Fee Related
  • 2015-11-02 SG SG11201702756UA patent/SG11201702756UA/en unknown
  • 2015-11-02 JP JP2017514307A patent/JP6526179B2/ja not_active Expired - Fee Related
• 2017
  • 2017-04-17 SA SA517381348A patent/SA517381348B1/ar unknown

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