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CN-121991720-A - Method for preparing coal-based mPAO and prepared mPAO

CN121991720ACN 121991720 ACN121991720 ACN 121991720ACN-121991720-A

Abstract

The present disclosure relates to a method for preparing coal-based mPAO and the prepared mPAO, the method comprises (1) performing a first cut and a first deoxidization treatment on coal-based Fischer-Tropsch synthesis light oil containing C5-C9 cut to obtain 1-nonene, performing a second cut and a second deoxidization treatment on coal-based Fischer-Tropsch synthesis heavy oil containing C10-C18 cut to obtain 1-tridecene, and (2) contacting the 1-nonene and the 1-tridecene in an inert atmosphere in the presence of a metallocene catalyst and an auxiliary agent to perform a polymerization reaction. The method disclosed by the invention has mild conditions, can widen the application field of the olefin raw material of the coal-based Fischer-Tropsch synthetic oil, improves the use efficiency of the odd-carbon alpha-olefin, and is high in viscosity, high in VI value and low in pour point.

Inventors

  • ZHU JIAQING
  • LI JIAHAO
  • YANG RUIHAN
  • YU YUE
  • LI HAO
  • TIAN DAYONG
  • CHEN JINGYUN
  • QIN SHAODONG
  • CHEN LINFENG

Assignees

  • 国家能源投资集团有限责任公司
  • 北京低碳清洁能源研究院

Dates

Publication Date
20260508
Application Date
20241106

Claims (10)

  1. 1. A method of making a coal-based mPAO, the method comprising: (1) Carrying out first fraction cutting and first deoxidation treatment on the coal-based Fischer-Tropsch synthesis light oil containing the C5-C9 fraction to obtain 1-nonene; cutting a second fraction and performing a second deoxidation treatment on the coal-based Fischer-Tropsch synthesis heavy oil containing the C10-C18 fraction to obtain 1-tridecene; (2) And (2) contacting the 1-nonene and the 1-tridecene in the presence of a metallocene catalyst and an auxiliary agent in an inert atmosphere to carry out polymerization reaction.
  2. 2. The process of claim 1, wherein the metallocene catalyst comprises a metallocene-bridged catalyst comprising one or more of rac-vinyl-bridged bis-indenyl zirconium dichloride, rac-ethylene bis (4, 5,6, 7-tetrahydro-1-indenyl) ] zirconium dichloride, rac-dimethylsilyl-bridged bis-indenyl zirconium dichloride, and rac-dimethylsilyl bis (4, 5,6, 7-tetrahydro-1-indenyl) zirconium dichloride; the auxiliary agent comprises one or more of borate and methylaluminoxane; The borate comprises one or more of N, N-dimethyl tetrafluorobenzene borate, methyl dioctadecyl ammonium tetra (pentafluorophenyl) borate and (tetrapentafluorophenyl) carbon triphenyl borate.
  3. 3. The method according to claim 1, wherein the amount of the 1-nonene is 30 to 70 mol% and the amount of the 1-tridecene is 30 to 70 mol% with respect to the total mole number of the 1-nonene and the 1-tridecene; Preferably, the dosage of the 1-nonene is 40-60 mol%, and the dosage of the 1-tridecene is 40-60 mol%; the dosage of the auxiliary agent is 1-50 mu mol% relative to the total mole number of the 1-nonene and the 1-tridecene, and the dosage of the metallocene catalyst is 1-100 mu mol%; Optionally, the auxiliary agent is added in a solution form, the concentration of a first solution containing the auxiliary agent is 1-100 mu mol%, and the first solvent in the first solution comprises one or more of toluene, xylene and C6-C18 saturated alkane; optionally, the metallocene catalyst is added in a solution form, the concentration of a second solution containing the metallocene catalyst is 1-50 mu mol%, and the second solvent in the second solution comprises one or more of toluene, xylene and saturated alkane of C6-C18.
  4. 4. The process according to claim 1, wherein the polymerization is carried out in a diluent comprising one or more of C6-C18 saturated alkanes, preferably n-nonane and/or n-tridecane.
  5. 5. The method according to claim 1, wherein the polymerization reaction conditions comprise a temperature of 30-150 ℃ for 10-180 min; The inert atmosphere comprises one or more of nitrogen, helium, neon and carbon dioxide.
  6. 6. The method according to claim 1, wherein the method further comprises contacting a pre-product obtained by the polymerization reaction with a hydrogenation catalyst to conduct hydrofining; The hydrofining condition comprises that the temperature is 100-300 ℃, the pressure is 2-6 MPa, the airspeed is 0.1-10 h -1 , and the hydrogen-oil ratio is 200-1000; the hydrogenation catalyst comprises one or more of a platinum catalyst, a palladium catalyst, a platinum-palladium bimetallic catalyst and a non-noble metal catalyst.
  7. 7. The method of claim 1, wherein the coal-based fischer-tropsch synthesis light oil has an initial boiling point of 29-36 ℃ and a final boiling point of 146-151 ℃; The initial distillation point of the coal-based Fischer-Tropsch synthesis heavy oil is 169-174 ℃, and the final distillation point is 310-316 ℃.
  8. 8. The coal-based mPAO prepared by the method according to any one of claims 1 to 7.
  9. 9. The coal-based mPAO according to claim 8, wherein the VI value of the coal-based mPAO is 200-250, the pour point is-27 ℃ to-51 ℃, the kinematic viscosity at 40 ℃ is 900-3000 cst, and the kinematic viscosity at 100 ℃ is 100-300 cst.
  10. 10. The coal-based mPAO according to claim 8, wherein the coal-based mPAO has a kinematic viscosity at 100 ℃ of 100-150 cst, a vi value of greater than 200, and a pour point of-45 ℃ or less; optionally, the coal-based mPAO has a kinematic viscosity at 100 ℃ of greater than 150cSt and less than 300cSt, a VI value of 230 or greater, and a pour point of less than-24 ℃.

Description

Method for preparing coal-based mPAO and prepared mPAO Technical Field The disclosure relates to the technical field of coal-based mPAO synthesis, in particular to a method for preparing coal-based mPAO and the prepared mPAO. Background Currently, the common polyolefin synthetic base oils mainly comprise two major classes of poly alpha-olefin (PAO) synthetic base oils and polyethylene synthetic base oils. PAO synthetic base oil is generally hydrogenated alpha-olefin oligomer obtained by oligomerization of raw material alpha-olefin (the main chemical component is alpha-C8-C10) under the action of one or more linear alpha-olefin under the action of catalyst, distillation, hydrogenation and other technological processes. The chemical structure composition of the isoparaffin is more regular and provided with a long side chain, and the isoparaffin has the characteristics of good thermal oxidation stability, low pour point, low volatility, high viscosity index, low sulfur/no sulfur, wide viscosity range and the like, and is favored in the market. The PAO obtained by metallocene catalytic polymerization is generally called mPAO, has a comb structure, does not have upright side chains, has high uniformity, and is particularly suitable for preparing industrial lubricating oil with very high stability requirements under extremely severe working conditions. The mPAO provides a better oil film thickness than the traditional synthetic poly-alpha-olefins (cPAO), helping to minimize wear of the lubricating oil even under extreme conditions. The high-viscosity lubricating oil also has the advantages of being unique in balance of shear stability and low-temperature performance, being wider in working temperature range of the lubricating oil, being low in pour point and good in Brinell viscosity, providing better low-temperature fluidity, being stronger in formula flexibility and the like. These characteristics allow the mPAO products to perform well in the wind power industry, and can provide longer lasting and durable lubrication oil for fan operators, minimizing maintenance costs and operational challenges. At present, catalysts for synthesizing PAO mainly comprise aluminum trichloride catalyst, boron trifluoride catalyst, ziegler-Natta catalyst, metallocene catalyst, ionic liquid catalyst and the like, wherein poly alpha-olefin (mPAO) obtained by metallocene catalytic polymerization has the following characteristics of (1) higher viscosity index, wider applicable temperature range, (2) better shear stability, better viscosity retention, longer oil change period, (3) better rheological property, small internal friction, improved energy-saving effect, and (4) better low-temperature performance and improved low-temperature fluidity of lubricating oil compared with other PAOs. In addition, most of the raw materials for producing PAO adopt C8-C10 linear alpha-olefin obtained by ethylene oligomerization. At present, the method for producing the mPAO has the problems of harsh conditions, low product viscosity, high pour point, poor regularity and the like. Disclosure of Invention It is an object of the present disclosure to provide a method of preparing coal-based mPAO and the resulting mPAO. To achieve the above object, a first aspect of the present disclosure provides a method of preparing an mPAO, the method comprising: (1) Performing first fraction cutting and first deoxidation treatment on the coal-based Fischer-Tropsch synthesis light oil containing the C5-C9 fraction to obtain 1-nonene, and performing second fraction cutting and second deoxidation treatment on the coal-based Fischer-Tropsch synthesis heavy oil containing the C10-C18 fraction to obtain 1-tridecene; (2) And (2) contacting the 1-nonene and the 1-tridecene in the presence of a metallocene catalyst and an auxiliary agent in an inert atmosphere to carry out polymerization reaction. Alternatively, the metallocene catalyst comprises a metallocene bridged catalyst comprising one or more of rac-vinyl bridged bis-indenyl zirconium dichloride, rac-ethylene bis (4, 5,6, 7-tetrahydro-1-indenyl) ] zirconium dichloride, rac-dimethylsilyl bridged bis-indenyl zirconium dichloride, and rac-dimethylsilyl bis (4, 5,6, 7-tetrahydro-1-indenyl) zirconium dichloride; the auxiliary agent comprises one or more of borate and methylaluminoxane; The borate comprises one or more of N, N-dimethyl tetrafluorobenzene borate, methyl dioctadecyl ammonium tetra (pentafluorophenyl) borate and (tetrapentafluorophenyl) carbon triphenyl borate. Optionally, the amount of the 1-nonene is 30-70 mol% and the amount of the 1-tridecene is 30-70 mol% relative to the total mole number of the 1-nonene and the 1-tridecene; Preferably, the dosage of the 1-nonene is 40-60 mol%, and the dosage of the 1-tridecene is 40-60 mol%; the dosage of the auxiliary agent is 1-50 mu mol% relative to the total mole number of the 1-nonene and the 1-tridecene, and the dosage of the metallocene catalyst is 1-100 mu mol%; O