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CN-118831619-B - Core-shell hydrogenation catalyst and preparation method thereof

CN118831619BCN 118831619 BCN118831619 BCN 118831619BCN-118831619-B

Abstract

The invention discloses a core-shell hydrogenation catalyst and a preparation method thereof, wherein the catalyst comprises a core layer and a shell layer, the core layer is alumina loaded with active metal components, the shell layer is alumina loaded with molybdenum carbide, and the active metal is at least one of VIII group metals and at least one of VIB group metals. The preparation method of the catalyst comprises the steps of firstly uniformly mixing pseudo-boehmite powder with an organic acid solution, drying, introducing an active metal component, forming to obtain a spherical core layer material, uniformly mixing the obtained spherical core layer material, the pseudo-boehmite powder, molybdenum carbide powder and an organic alcohol high polymer solution under the rolling ball forming condition to obtain a catalyst precursor, and finally drying and roasting the catalyst precursor to obtain the core-shell hydrogenation catalyst. The hydrogenation catalyst provided by the invention is especially suitable for the hydrogenation conversion of petroleum products containing macromolecular aromatic hydrocarbons and polycyclic aromatic hydrocarbons, such as heavy oil, coal tar and the like.

Inventors

  • LIU LU
  • SHI YIMING
  • SHENG QINGQING
  • ZHU HUIHONG
  • YANG TAO

Assignees

  • 中国石油化工股份有限公司
  • 中石化（大连）石油化工研究院有限公司

Dates

Publication Date
20260505
Application Date
20230418

Claims (20)

  1. 1. The core-shell hydrogenation catalyst comprises a core layer and a shell layer, wherein the core layer is alumina loaded with active metal components, the shell layer is alumina loaded with molybdenum carbide, the active metal is at least one of VIII group metals and at least one of VIB group metals, the content of the molybdenum carbide is 2.0-10.0 wt% based on the total weight of the shell layer, the pore volume of pores with the pore diameter of 6-15nm accounts for 40-60% of the total pore volume, the pore volume of pores with the pore diameter of >100nm accounts for more than 15% of the pore volume of the core layer, the VIII group metals are Ni and/or Co, the VIB group metals are Mo or Mo and W, the content of the VIII group metals is 1.0-8.0 wt% based on the total weight of the core layer and the content of the VIB group metals is 5.0-20.0 wt%, and the mole ratio of hexavalent molybdenum and divalent molybdenum in the VIB group metals is 0.2-10.
  2. 2. The core-shell hydrogenation catalyst according to claim 1, wherein the content of molybdenum carbide is 4.0wt% to 8.0wt% based on the total weight of the shell.
  3. 3. The core-shell hydrogenation catalyst according to claim 1, wherein the content of the group VIII metal is 2.0wt% to 4.0wt% and the content of the group VIB metal is 8.0wt% to 15.0wt% based on the total weight of the core layer, calculated as metal oxide.
  4. 4. The core-shell hydrogenation catalyst according to claim 1, wherein the pore volume of the catalyst is 0.40-0.80mL/g and the specific surface area is 150-280m 2 /g.
  5. 5. The core-shell hydrogenation catalyst according to claim 1, wherein the pore volume of the catalyst is 0.45-0.75mL/g and the specific surface area is 160-260m 2 /g.
  6. 6. The core-shell hydrogenation catalyst according to claim 1, wherein the volume ratio of the core layer to the shell layer of the catalyst is 1:3.6-1:0.38.
  7. 7. A process for preparing the core-shell hydrogenation catalyst according to any one of claims 1 to 6, comprising the steps of: (1) Mixing pseudo-boehmite powder with an organic acid solution, uniformly mixing, drying, introducing an active metal component, and performing shaping treatment to obtain a spherical core layer material; (2) Under the rolling ball forming condition, uniformly mixing the spherical nuclear layer material obtained in the step (1), pseudo-boehmite powder, molybdenum carbide powder and organic alcohol high polymer solution to obtain a catalyst precursor; (3) And (3) drying and roasting the catalyst precursor obtained in the step (2) to obtain the core-shell hydrogenation catalyst.
  8. 8. The method for preparing a core-shell hydrogenation catalyst according to claim 7, wherein the concentration of the organic acid solution in said step (1) is 1.0wt% to 10.0wt% and the organic acid is at least one selected from the group consisting of monobasic acids and polybasic acids.
  9. 9. The method for preparing a core-shell hydrogenation catalyst according to claim 7, wherein the concentration of the organic acid solution in the step (1) is 2.0wt% to 6.0wt%.
  10. 10. The method for preparing a core-shell hydrogenation catalyst according to claim 7, wherein the organic acid in the step (1) is an organic acid having 3 to 8 carbon atoms.
  11. 11. The method for preparing a core-shell hydrogenation catalyst according to claim 8, wherein the organic acid in the step (1) is one or more of citric acid, tartaric acid and acrylic acid.
  12. 12. The method for preparing a core-shell hydrogenation catalyst according to claim 7, wherein the organic acid solution in the step (1) is added in an amount of 1.0 to 8.0wt% based on the dry weight of the pseudo-boehmite powder in the step (1).
  13. 13. The method for preparing a core-shell hydrogenation catalyst according to claim 7, wherein the organic acid solution in the step (1) is added in an amount of 2.0 to 6.0wt% based on the dry weight of the pseudo-boehmite powder in the step (1).
  14. 14. The method for preparing a core-shell hydrogenation catalyst according to claim 7, wherein the drying conditions in the step (1) are such that the drying temperature is 60 ℃ to 150 ℃ and the drying time is 1h to 20h.
  15. 15. The method for preparing a core-shell hydrogenation catalyst according to claim 7, wherein the drying conditions in the step (1) are as follows, the drying temperature is 80-120 ℃ and the drying time is 2-8 h.
  16. 16. The method for preparing a core-shell hydrogenation catalyst according to claim 7, wherein the precursor of the active metal component in the step (1) is one or a mixture of two or more of an oxide containing the active metal component and a salt containing the active metal component.
  17. 17. The preparation method of the core-shell hydrogenation catalyst according to claim 13, wherein the molybdenum precursor is industrial molybdenum trioxide and/or ammonium heptamolybdate, the tungsten precursor is one or more of ammonium metatungstate, sodium tungstate and tungsten phosphoric acid, the nickel precursor is one or more of nickel nitrate, nickel acetate, basic nickel carbonate and nickel chloride, and the cobalt precursor is one or more of cobalt nitrate, cobalt acetate, basic cobalt carbonate and cobalt chloride.
  18. 18. The method for preparing a core-shell hydrogenation catalyst according to claim 17, wherein the precursor of molybdenum is industrial grade molybdenum trioxide, the precursor of nickel is basic nickel carbonate, and the precursor of cobalt is basic cobalt carbonate.
  19. 19. The method for preparing a core-shell hydrogenation catalyst according to claim 7, wherein the shaping in the step (1) is spherical, and the particle size of the spherical core layer material is controlled to be 0.3mm-1.0mm.
  20. 20. The method for preparing a core-shell hydrogenation catalyst according to claim 7, wherein the shaping in the step (1) is spherical, and the particle size of the spherical core layer material is controlled to be 0.4 mm-0.8mm.

Description

Core-shell hydrogenation catalyst and preparation method thereof Technical Field The invention belongs to the technical field of petrochemical catalysis, relates to a catalytic material and a preparation method thereof, and particularly relates to a material for hydrogenation catalysis and a preparation method thereof. Background With the increasing weight of international crude oil and the increasing market demand for distillate oil and chemical raw materials, the hydroconversion of inferior heavy oil to produce high quality products becomes more attractive. Oil products such as residual oil and the like contain a large amount of colloid and asphaltene, while oil products such as ethylene tar and coal tar and the like contain more polycyclic aromatic hydrocarbon, have large molecules and high unsaturation degree, are difficult to hydrogenate due to steric hindrance effect in the hydroconversion process, and are easy to produce carbon deposit to cause blocking of catalyst pore channels so as to influence the hydrogenation effect of the catalyst. CN200910083078.3 discloses a hydrocracking catalyst and a preparation method thereof, the catalyst is composed of a main catalyst and a cocatalyst, the main catalyst is aluminosilicate loaded with transition metal, the cocatalyst is selected from one or a mixture obtained by mixing more than two of nitrogen-containing heterocyclic compounds, aromatic nitrogen-containing compounds and acyl nitrogen-containing compounds, and the main catalyst and the cocatalyst are mixed to obtain the catalyst suitable for hydrocracking heavy distillate. The preparation method belongs to simple mixing of the cocatalyst and the main catalyst, and has weak synergism. The core-shell structure catalyst can produce progressive catalytic effect on oil molecules, and the oil molecules further enter a core layer for conversion after the shell layer is processed. The preparation process of the core-shell catalyst is one of key factors influencing the catalytic efficiency of the core-shell catalyst. CN202110228071.7 discloses a core-shell catalyst, the preparation method of the core-shell catalyst adopts different electronic auxiliary agents to regulate and control the catalytic performance of the iron-based catalyst, and the control of the surface acidity and pore canal structure of the molecular sieve is realized through direct ion exchange and alkaline solution pore-enlarging treatment, which is applied to the field of carbon dioxide hydrogenation. The preparation method of the core-shell structure is to wrap the molecular sieve carrier with the active metal in a physical coating mode, and the dispersibility of the active metal and the synergy with the molecular sieve carrier are required to be improved. CN201710709622.5 discloses a hydrogenation catalyst with core-shell structure, which contains non-acidic or weak acid porous carrier and at least two metal elements or compounds selected from VIII, VIB, VIIB loaded on the carrier, the metal elements or compounds are in core-shell distribution on the surface of the carrier, the core-shell distribution is carried twice in the same way, so that the shell is covered on the core layer. The realization method of the core-shell distribution ensures that the colloid asphaltene is hydrogenated in the pore canal of the conventional catalyst, is influenced by steric hindrance, limits the hydrogenation conversion of active metal to macromolecules in the pore canal to a certain extent, covers the core layer by the shell layer, and has slightly insufficient metal utilization rate. Disclosure of Invention The core purpose of the invention is to provide a core-shell hydrogenation catalyst and a preparation method thereof, wherein microspherical particles are used as a core layer, a shell layer which has a large aperture and contains molybdenum carbide active components is wrapped in a rolling forming mode, the core layer has hydrogenation activity on annular and chain small molecules while the inside and outside of pore channels of the catalyst particles are large, and the shell layer has hydrogenation activity on polycyclic aromatic hydrocarbon rich in pi-bond electrons, so that the step-by-step hydrogenation of the spherical catalyst particle shell layer and the core layer and the step utilization of the pore channels are realized. The hydrogenation catalyst provided by the invention is especially suitable for the hydrogenation conversion of petroleum products containing macromolecular aromatic hydrocarbons and polycyclic aromatic hydrocarbons, such as heavy oil, coal tar and the like. The first aspect of the invention provides a core-shell hydrogenation catalyst, which comprises a core layer and a shell layer, wherein the core layer is alumina loaded with active metal components, the shell layer is alumina loaded with molybdenum carbide, and the active metal is at least one of VIII group metals and at least one of VIB group metals. In the core-shell hydr