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CN-122010801-A - Method for preparing organic polysulfide

CN122010801ACN 122010801 ACN122010801 ACN 122010801ACN-122010801-A

Abstract

The invention discloses a method for preparing organic polysulfide, which comprises the steps of adding mercaptan, sulfur and an alkaline catalyst into a reactor with an outlet connected with a gas separation device to carry out a vulcanization reaction, thereby obtaining the organic polysulfide, wherein the gas separation device comprises a membrane separation unit, a condensation unit and a pressure regulating unit, and a membrane component for separating mercaptan and gas is arranged in the membrane separation unit. In the invention, the organic polysulfide is prepared by mercaptan and sulfur, and a gas separation device is added for solving the problem of high consumption of mercaptan in the reaction process. By utilizing the method, inorganic gases such as H 2 S and the like in the reaction process can be efficiently separated, mercaptan and thioether obtained by synthesis are reserved to the maximum extent, the loss of the mercaptan is reduced, the cost is reduced, and the reaction efficiency and the product purity are improved.

Inventors

  • JIA YANFEI
  • WANG QINGCHAO
  • LIU YAFANG
  • WANG RONGZHEN
  • LIU XILIN
  • FAN JINFENG

Assignees

  • 新乡市瑞丰新材料股份有限公司

Dates

Publication Date
20260512
Application Date
20251205

Claims (9)

  1. 1. A method of preparing an organic polysulfide, the method comprising: Adding mercaptan, sulfur and alkaline catalyst into a reactor with an outlet connected with a gas separation device to carry out sulfuration reaction, thereby obtaining organic polysulfide, The gas separation device comprises a membrane separation unit, a condensation unit and a pressure regulating unit, wherein a membrane component for separating mercaptan and H 2 S is arranged in the membrane separation unit.
  2. 2. The method according to claim 1, wherein the membrane module is a hollow fiber membrane or a flat plate membrane module made of a microporous membrane material selected from any one of Polytetrafluoroethylene (PTEE), polyimide (PI) and Polyethersulfone (PES), preferably polytetrafluoroethylene, and has a pore diameter ranging from 0.01 μm to 5 μm, preferably from 0.3 μm to 0.5 μm, more preferably from 0.1 μm to 0.5 μm.
  3. 3. The process according to claim 1 or 2, wherein the operating temperature within the membrane separation unit is 20-60 ℃, the operating pressure is 0.1-0.3MPa, and the gas flow rate is 100-200m 3 /h.
  4. 4. A process according to any one of claims 1 to 3, wherein the molar ratio of thiol added to sulfur is 1 (1-4), preferably 1 (1-2), more preferably 1:1, and the amount of alkaline additive added is 1-10 parts by mass, preferably 1-5 parts by mass, more preferably 1-3 parts by mass, relative to 100 parts by mass of the sum of thiol and sulfur.
  5. 5. The process according to any one of claims 1 to 4, wherein the reaction is carried out at a temperature of 40 ℃ to 90 ℃ for 2h to 10h, preferably 4h to 10h, more preferably 5h to 8h.
  6. 6. The process according to any one of claims 1 to 5, wherein the mercaptan is a linear or branched mercaptan having 1 to 18 carbon atoms, preferably a linear or branched mercaptan having 1 to 10 carbon atoms, more preferably one or more selected from the group consisting of isopropyl mercaptan, t-butyl mercaptan, neopentyl mercaptan, t-octyl mercaptan and n-hexyl mercaptan, and the sulfur has a purity of 90% or more, preferably 95% or more, more preferably 98% or more.
  7. 7. The method of any one of claims 1 to 6, wherein the basic catalyst is selected from any one of alumina, zinc oxide, and zirconia.
  8. 8. The method of any one of claims 1 to 7, wherein the membrane separation unit further comprises a housing, a gas inlet, a gas outlet and a permeate outlet, wherein the housing houses the membrane module, the gas inlet is connected to a gas outlet of the reactor, the gas outlet is connected to a subsequent treatment plant or recycled back to the reactor, and the permeate outlet discharges the gas.
  9. 9. The method of any one of claims 1 to 8, wherein the membrane modules are arranged in a multistage series or parallel arrangement and each stage has a membrane area of not less than 3m 2 .

Description

Method for preparing organic polysulfide Technical Field The invention belongs to the technical field of chemical production, and particularly relates to a method for preparing organic polysulfide. Background The organic polysulfide is used as an important extreme pressure antiwear agent component and has wide application in the field of industrial lubrication. Organic polysulfides such as trisulfide have both optimal sulfur content and lower copper flake corrosiveness, and become ideal lubricating oil additives meeting both extreme pressure antiwear and copper corrosiveness requirements. At present, the product obtained by synthesizing organic polysulfide by using mercaptan and sulfur as raw materials is relatively pure, but the mercaptan has high cost, and a large amount of mercaptan is lost when hydrogen sulfide gas is discharged in the reaction process, so that the consumption of the mercaptan is increased. CN115477601a discloses a process for the preparation of organic polysulfides. The patent firstly uses metal hydroxide to react with sulfur to generate metal sulfide, the metal sulfide further carries out substitution reaction with alkyl chain containing halogen atoms, and finally organic polysulfide is obtained after extraction, washing and distillation. However, the method can generate a large amount of metal salt byproducts in the reaction process, and the subsequent separation and purification procedures are complicated, so that the cost is increased, and the environmental pollution is easily caused. US5442123a discloses a process for the preparation of organic polysulfides. The method is characterized in that mercaptan and sulfur are used as raw materials, and organic trisulfide is selectively prepared under the action of an alkali metal catalyst. In the reaction process, H 2 S needs to be discharged in a high-temperature reflux mode in time so as to promote the reaction. However, during the removal of H 2 S, a large amount of mercaptans can be carried out of the reaction system, resulting in loss of mercaptans, which in turn ultimately leads to increased costs. Therefore, it is of great importance to develop an efficient, low-cost and environment-friendly method for preparing organic polysulfides based on the reaction of mercaptan and sulfur. Disclosure of Invention To solve the above technical problem, an object of the present invention is to provide a method for preparing organic polysulfide, the method comprising: Adding mercaptan, sulfur and alkaline catalyst into a reactor with an outlet connected with a gas separation device to carry out sulfuration reaction, thereby obtaining organic polysulfide, The gas separation device comprises a membrane separation unit, a condensation unit and a pressure regulating unit, wherein a membrane component for separating mercaptan and H 2 S is arranged in the membrane separation unit. Preferably, the membrane module is a hollow fiber membrane or a flat plate membrane module made of a microporous membrane material selected from any one of Polytetrafluoroethylene (PTEE), polyimide (PI) and Polyethersulfone (PES), preferably polytetrafluoroethylene, and has a pore diameter ranging from 0.01 μm to 5 μm, preferably from 0.3 μm to 0.5 μm, more preferably from 0.1 μm to 0.5 μm. Preferably, the operating temperature in the membrane separation unit is 20-60 ℃, the operating pressure is 0.1-0.3MPa, and the gas flow rate is 100-200m 3/h. The invention has at least the following beneficial effects: The product obtained by the method has high conversion rate and simple operation process, and can separate out inorganic gases such as H 2 S and the like in the reaction process, and retain mercaptan and thioether obtained by synthesis. The method has high recovery rate of mercaptan and reduces the cost. In addition, the high-efficiency separation of H 2 S by the gas separation device reduces the refining flow, reduces the corrosion of H 2 S to equipment, and prolongs the service life of the equipment. Detailed Description The following detailed description of the present invention will be presented for a clearer understanding of the technical features, objects and advantages of the present invention, but should not be construed as limiting the scope of the invention. It is noted that all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs unless otherwise indicated. The various raw materials, reagents, instruments, equipment, etc., used in the present invention are commercially available or may be prepared by existing methods unless otherwise specifically indicated. It will be understood that the terms "comprises," "comprising," "includes," and/or "including," when used herein, specify the presence of stated features, integers, steps, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, components, or