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CN-117504894-B - Preparation of hydrogenation catalyst and out-of-device presulfiding and catalytic pyrolysis gasoline start-up method

CN117504894BCN 117504894 BCN117504894 BCN 117504894BCN-117504894-B

Abstract

The invention discloses a preparation method of a hydrogenation catalyst and an in-vitro presulfiding and catalytic pyrolysis gasoline startup method. The preparation method of the hydrogenation catalyst comprises the steps of adding a carrier into an impregnating pot, carrying out atomization spraying treatment on the carrier by adopting a pre-spraying solution, carrying out aging treatment after spraying is finished, impregnating an active component on the carrier, aging, drying and roasting. The catalyst prepared by the method has reasonable gradient distribution of active components and excellent hydrofining performance.

Inventors

  • HU XIAOLI
  • MA PING
  • MA HAOWEN
  • XIE YUAN
  • DUAN HONGCHANG
  • FU HANQI
  • SUN LIMIN
  • ZHAN XUECHENG
  • GUO DAJIANG
  • CHEN MINGLIN

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260505
Application Date
20230112
Priority Date
20220803

Claims (19)

  1. 1. A method for preparing a hydrogenation catalyst, comprising: the method comprises the steps of (1) adding a carrier into an impregnating kettle, and carrying out atomization spraying treatment on the carrier by adopting a pre-spraying solution, wherein the spraying treatment time is 1-20 min, and after spraying, carrying out aging treatment for 5-30 min; step (2), dipping the active component dipping liquid on the carrier treated in the step (1), aging, drying and roasting; the specific surface area of the carrier is 120-260 m 2 /g, and the water absorption rate of the carrier is 70-120%; The volume of the active component impregnating solution is 1.05X (the percentage of the 1-pre-spraying solution added) X T-1.25X (the percentage of the 1-pre-spraying solution added) X Tml, wherein the water absorption rate of the carrier is expressed as X, and the mass of the carrier is expressed as T grams; The volume percentage of the pre-spray solution is 1% -20% of the total volume of the impregnating solution, and the total volume of the impregnating solution is the sum of the volume of the pre-spray solution and the volume of the impregnating solution of the active component.
  2. 2. The method of claim 1, wherein the pre-spray solution is an aqueous citric acid solution or an aqueous potassium hydroxide solution.
  3. 3. The method of claim 2, wherein: When the pre-spraying solution is an aqueous solution of citric acid, adding salt containing an active component into an aqueous solution of inorganic acid to prepare an active component impregnating solution so as to impregnate the carrier with the active component impregnating solution; Or alternatively, the first and second heat exchangers may be, When the pre-spray solution is a potassium hydroxide solution, mixing potassium hydroxide, ammonia water, a polyamine complexing agent and deionized water to prepare a composite solvent, and adding salt containing an active component into the composite solvent to prepare an active component impregnating solution so as to impregnate the carrier.
  4. 4. A method according to claim 3, wherein the active component is molybdenum, cobalt, nickel.
  5. 5. The method of claim 4, wherein the salt of the active component is ammonium molybdate and/or molybdenum oxide, cobalt nitrate and/or cobalt acetate, nickel nitrate and/or nickel acetate.
  6. 6. The method of claim 1, wherein the spraying treatment time is 3-10 min and the aging treatment time is 10-20 min.
  7. 7. The method of claim 1, wherein the specific surface area of the carrier is 150-220 m 2 /g, and the water absorption rate of the carrier is 80-100%.
  8. 8. The method of claim 1, wherein the active ingredient impregnation fluid has a volume of 1.10X (percent of 1-pre-spray solution addition) X T to 1.20X (percent of 1-pre-spray solution addition) X Tml.
  9. 9. The method of claim 1, wherein the pre-spray solution comprises 5% to 10% by volume of the total impregnating solution.
  10. 10. A hydrogenation catalyst obtainable by the process of any one of claims 1 to 9.
  11. 11. The hydrogenation catalyst according to claim 10, wherein the hydrogenation catalyst comprises 10 to 20wt% of molybdenum oxide, 1.5 to 8wt% of nickel oxide, 0 to 5wt% of cobalt oxide, and the balance being a carrier.
  12. 12. The hydrogenation catalyst according to claim 11, wherein the hydrogenation catalyst comprises 13-18wt% of molybdenum oxide, 2-6wt% of nickel oxide, 0.5-2.5wt% of cobalt oxide and the balance of a carrier.
  13. 13. The method for ex-situ presulfiding of a hydrogenation catalyst according to any one of claims 10 to 12, comprising: the hydrogenation catalyst according to any one of claims 10-12 is placed in an impregnating pot, and the presulfiding raw material is uniformly mixed with the hydrogenation catalyst in a spraying mode.
  14. 14. The ex-situ prevulcanization process according to claim 13, characterized in that the prevulcanization raw material is a mixture of a vulcanizing agent and a vulcanizing aid; the dosage of the vulcanizing agent is 20-70% of the theoretical sulfur demand of the hydrogenation catalyst; the dosage of the vulcanization aid is 0.5-40% of the weight of the hydrogenation catalyst.
  15. 15. The method for pre-vulcanizing outside a reactor according to claim 14, wherein the vulcanizing agent is used in an amount of 25-50% of the theoretical sulfur demand of the hydrogenation catalyst, and the vulcanizing aid is used in an amount of 3-25% of the weight of the hydrogenation catalyst.
  16. 16. The presulfided hydrogenation catalyst prepared by the ex-situ presulfiding method of any one of claims 13 to 15.
  17. 17. The presulfiding hydrogenation catalyst of claim 16, wherein the mass ratio of elemental sulfur to active metal in the presulfiding hydrogenation catalyst is 0.2 to 0.7.
  18. 18. The presulfiding hydrogenation catalyst of claim 17, wherein the mass ratio of elemental sulfur to active metal in the presulfiding hydrogenation catalyst is 0.25 to 0.5.
  19. 19. The method for starting the catalytic pyrolysis gasoline is characterized by comprising the following steps: Loading the presulfided hydrogenation catalyst of any one of claims 16-18 into a reactor; After the airtight detection is qualified, the inlet temperature of the reactor is increased at a speed of 15-25 ℃ per hour under the hydrogen circulation condition, and the temperature of the catalyst bed is kept constant for 3-5 hours when the temperature of the catalyst bed reaches 150-160 ℃, the temperature of the catalyst bed is kept constant for 2-10 hours when the temperature of the catalyst bed reaches 180-220 ℃, and the temperature of the catalyst bed is kept constant for 4-10 hours when the temperature of the catalyst bed reaches 260-320 ℃; and (3) adjusting the reaction conditions required by the system process, and switching the raw oil to perform normal operation.

Description

Preparation of hydrogenation catalyst and out-of-device presulfiding and catalytic pyrolysis gasoline start-up method Technical Field The invention relates to a preparation method of a hydrogenation catalyst and an in-vitro presulfiding and catalytic pyrolysis gasoline start-up method. Background Aromatic hydrocarbon is taken as a basic chemical raw material, has an important role, the production technology and the production level thereof are one of the marks of the national petrochemical development level, the world demand for aromatic hydrocarbon products is continuously increased, and the output of aromatic hydrocarbon products in China cannot meet the demand. At present, the main source of aromatic hydrocarbon is obtained by extracting and separating catalytic reforming gasoline and pyrolysis gasoline which is a byproduct of an ethylene device. Therefore, the method widens the sources of the aromatic hydrocarbon extraction raw materials, and has important significance for improving the autonomous supply capacity of the aromatic hydrocarbon market in China and reducing the dependence on foreign markets. The catalytic cracking process is developed on the basis of the catalytic cracking process technology, and gasoline with high aromatic hydrocarbon content can be produced by catalytic cracking through process adjustment to serve as a raw material for producing aromatic hydrocarbon. However, the aromatic hydrocarbon product has very strict requirements on sulfur, nitrogen and other impurities, so that saturated olefins are needed before the catalytic pyrolysis gasoline is subjected to aromatic hydrocarbon extraction, and sulfur, nitrogen and other impurities in the catalytic pyrolysis gasoline are removed. The catalytic cracking process is relatively late, and the catalytic cracking gasoline hydrogenation catalyst and the hydrotreating process have fewer patent documents. The hydrogenation technology taking the pyrolysis gasoline hydrogenation catalyst of the byproduct of preparing ethylene by steam pyrolysis as a core is an important branch in the hydrogenation field, and can provide reference for the catalytic pyrolysis gasoline hydrogenation treatment technology. However, the catalytic pyrolysis gasoline and the steam pyrolysis gasoline have certain differences, and the main appearance is that the catalytic pyrolysis gasoline has high nitrogen, sulfur and diene content and relatively heavy components. The steam pyrolysis process has light material oil fraction, relatively low sulfur content and no nitrogen content, and the catalytic pyrolysis process has heavy material oil or residual oil and high sulfur and nitrogen content. Therefore, the inferior catalytic pyrolysis gasoline puts higher demands on the hydrofining catalyst. The hydrofining process of the catalytic pyrolysis gasoline with the aim of producing the aromatic hydrocarbon extraction raw material needs to solve 2 key problems, namely, the catalyst has lower aromatic hydrocarbon saturation activity under higher desulfurization, denitrification and olefin saturation activity, and the requirement on the coking resistance of the catalyst is higher, so that the long-period stable operation of the device is ensured. Hydrofining catalysts are classified into supported and unsupported catalysts, and commercial applications are prevalent with supported catalysts. The supported hydrofining catalyst is generally prepared by impregnating active metal (Mo, W, ni, co, etc.) onto a carrier, and the active components of the catalyst prepared by the impregnation method are distributed on the inner and outer surfaces of the catalyst carrier, including inner deep pores and the inner surfaces of the pores. The active metal of the hydrofining catalyst prepared by the conventional method is in an oxidation state, and a substance which really plays a catalytic role in actual use is in a vulcanization state of an active component, so that the catalyst needs to be subjected to vulcanization activation before use, and is called presulfiding. Pre-sulfiding of the catalyst has an important impact on the performance of the catalyst, being an important treatment step prior to catalyst application. The method for presulfiding the catalyst can be classified into in-reactor presulfiding and out-of-reactor presulfiding according to the sulfur-carrying mode. The in-reactor presulfiding technology is to load the catalyst into a reactor and then to carry out sulfiding treatment. The hydrogen sulfide required by the reaction is usually prepared by decomposing with a vulcanizing agent, and dimethyl disulfide (hereinafter referred to as DMDS) is generally adopted in industry, wherein the main vulcanizing step is that the DMDS is gradually injected into a system in a state of hot hydrogen circulation (the inlet temperature of a reactor reaches 180 ℃), then the DMDS is decomposed with hydrogen to release hydrogen sulfide gas, and then the hydrogen sulfide gas reacts with an oxidati