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CN-121988376-A - Cracking catalyst and preparation method and application thereof

CN121988376ACN 121988376 ACN121988376 ACN 121988376ACN-121988376-A

Abstract

The invention discloses a cracking catalyst and a preparation method and application thereof, wherein the cracking catalyst comprises a first component and a second component, and the first component is a nickel modified ZSM-5 molecular sieve; the second component is amorphous silica alumina loaded with an active metal component. The preparation method of the cracking catalyst comprises the steps of (1) treating a ZSM-5 molecular sieve to obtain a first ZSM-5 molecular sieve, (2) treating the first ZSM-5 molecular sieve and an ammonium salt solution to obtain a second ZSM-5 molecular sieve, (3) treating the second ZSM-5 molecular sieve and a nickel-containing compound solution to obtain a first material, (4) treating amorphous silicon aluminum and an active metal precursor solution to obtain a second material, and (5) mixing the first material, the second material and water, and drying and roasting to obtain the cracking catalyst. Also provides a plastic and heavy oil co-conversion process. After the cracking catalyst is used, the yield of liquid products can be obviously improved, carbon deposition of the catalyst can be reduced, and the service life of the catalyst can be prolonged.

Inventors

  • LIU BIN
  • XU LIMING
  • TONG JIA

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
20260508
Application Date
20241101

Claims (20)

  1. 1. A cracking catalyst comprises a first component and a second component, wherein the first component is a nickel modified ZSM-5 molecular sieve, the second component is amorphous silica-alumina loaded with an active metal component, and the active metal is one or more of metals of a VIB group, preferably Mo and/or W.
  2. 2. The cracking catalyst of claim 1, wherein the ratio of the first component to the second component is 1:1 to 4:1, preferably 2:1 to 3:1, based on the weight of the cracking catalyst.
  3. 3. The cracking catalyst according to claim 1, wherein the nickel is present in an amount of 1.0wt% to 5.0wt%, preferably 2wt% to 4wt%, calculated as oxide, based on the weight of the first component.
  4. 4. The cleavage catalyst as claimed in claim 1, wherein the specific surface area of the first component is 300m 2 /g～380 m 2 /g, preferably 330 m 2 /g～360 m 2 /g, the pore volume is 0.36 cm 3 /g～0.48 cm 3 /g, preferably 0.42 cm 3 /g～0.47 cm 3 /g.
  5. 5. The cracking catalyst of claim 1, wherein the mesoporous volume of the first component and the micropores Kong Rongbi are 1.4:1-2.2:1, preferably 1.6:1-2.0:1, wherein the micropores are pores smaller than 2nm, and the mesopores are pores of 2-50 nm.
  6. 6. The cracking catalyst according to claim 1, wherein the first component has a total acid content of 0.214mmol/g to 0.226mmol/g as characterized by NH 3 -TPD, a weak acid ratio of 48.20% -53.86%, a medium strong acid ratio of 43.46% -47.62%, and a strong acid ratio of 2.32% -2.86%, wherein the peak desorbed at 150 ℃ -250 ℃ is a weak acid, the peak desorbed at 250 ℃ -400 ℃ is a medium strong acid, and the peak desorbed at 400 ℃ -500 ℃ is a strong acid.
  7. 7. The cracking catalyst according to claim 1, wherein the active metal is present in an amount of 2 to 7wt%, preferably 3 to 6wt%, calculated as oxide, based on the weight of the second component.
  8. 8. The cracking catalyst according to claim 1, wherein the second component further comprises phosphorus in an amount of 0.1% to 0.4% by element based on the weight of the second component.
  9. 9. A cracking catalyst according to claim 1, wherein the specific surface area of the catalyst is 260 m 2 /g～340 m 2 /g, preferably 270 m 2 /g～300m 2 /g, and/or, The pore volume of the catalyst is 0.43 cm 3 /g～0.55cm 3 /g, preferably 0.47cm 3 /g～0.52cm 3 /g.
  10. 10. The cracking catalyst according to claim 1, wherein the catalyst has a total acid content of 0.208-mmol/g to 0.219mmol/g, a weak acid ratio of 45.70-51.30%, a medium strong acid ratio of 46.12-52.18%, and a strong acid ratio of 2.12-2.58, characterized by NH 3 -TPD, wherein the peak desorbed at 150-250 ℃ is a weak acid, the peak desorbed at 250-400 ℃ is a medium strong acid, and the peak desorbed at 400-500 ℃ is a strong acid.
  11. 11. A method of preparing a cracking catalyst, the method comprising the steps of: (1) Treating the ZSM-5 molecular sieve in the presence of an alkaline compound aqueous solution, separating, washing, drying and roasting to obtain a first ZSM-5 molecular sieve; (2) Contacting the first ZSM-5 molecular sieve obtained in the step (1) with an ammonium salt solution for treatment, and separating, drying and roasting to obtain a second ZSM-5 molecular sieve; (3) Contacting the second ZSM-5 molecular sieve treated in the step (2) with a nickel-containing compound solution for treatment, and drying to obtain a first material; (4) Contacting amorphous silicon aluminum with an active metal precursor solution for treatment, and drying to obtain a second material; (5) And (3) mixing the first material obtained in the step (3) with the second material obtained in the step (4) and water in the presence of a binder, and drying and roasting to obtain the cracking catalyst.
  12. 12. The method for preparing a cracking catalyst according to claim 11, wherein the ZSM-5 molecular sieve in the step (1) is an H-type ZSM-5 molecular sieve having a Si/Al ratio of 60 to 100.
  13. 13. The method for preparing a cracking catalyst according to claim 11, wherein the alkaline compound in the step (1) is one or more of sodium carbonate, sodium hydroxide and sodium bicarbonate, preferably sodium carbonate, and the concentration of the aqueous alkaline compound solution is 0.2 mol mol/L-0.8 mol/L, preferably 0.3 mol/L-0.5 mol/L.
  14. 14. The method for preparing a cracking catalyst according to claim 11, wherein the mass ratio of the volume of the aqueous alkaline compound solution to the ZSM-5 molecular sieve in the step (1) is 10:1 to 20:1, preferably 13:1 to 16:1.
  15. 15. The method for preparing a cracking catalyst according to claim 11, wherein the treatment temperature in the step (1) is 50 ℃ to 90 ℃, preferably 70 ℃ to 85 ℃, and the treatment time is 2h to 8h, preferably 3h to 5h.
  16. 16. The method for preparing a cracking catalyst according to claim 11, wherein the roasting temperature in the step (1) is 400-600 ℃, preferably 420-480 ℃, and the roasting time is 4-10 hours, preferably 6-8 hours.
  17. 17. The method for preparing a cracking catalyst according to claim 11, wherein the total acid amount of the first ZSM-5 molecular sieve obtained after calcination in the step (1) is 0.09mmol/g to 0.116 mmol/g as measured by NH 3 -TPD, wherein the weak acid accounts for 83.32% -87.24%, the medium strong acid accounts for 13.66% -15.68%, and the strong acid accounts for 1.12% -1.36%, wherein the peak desorbed at 150 ℃ -250 ℃ is weak acid, the peak desorbed at 250 ℃ -400 ℃ is medium strong acid, and the peak desorbed at 400 ℃ -500 ℃ is strong acid.
  18. 18. The method for preparing a cracking catalyst according to claim 11, wherein the ammonium salt in the step (2) is one or more of ammonium nitrate, ammonium chloride and ammonium sulfate, preferably ammonium nitrate, and the concentration of the ammonium salt solution is 0.2 mol/L-0.6 mol/L, preferably 0.3 mol/L-0.4 mol/L.
  19. 19. The method for preparing a cracking catalyst according to claim 11, wherein the mass ratio of the volume of the ammonium salt solution in the step (2) to the first ZSM-5 molecular sieve is 8:1 to 20:1, preferably 10:1 to 12:1.
  20. 20. The method for preparing a cracking catalyst according to claim 11, wherein the baking temperature in the step (2) is 400-600 ℃, preferably 500-550 ℃, and the baking time is 4-10 hours, preferably 6-8 hours.

Description

Cracking catalyst and preparation method and application thereof Technical Field The invention belongs to the technical field of petrochemical industry, relates to a catalytic material and a preparation method thereof, and particularly relates to a cracking catalyst and a preparation method and application thereof. Background At present, plastics are widely used in various aspects of society due to excellent durability, corrosion resistance, plasticity, stability and the like, and the production and consumption thereof have become important indexes for evaluating the industrial development level and the quality of life of people. However, with the use of a large amount of plastic products, the problem is that the current proportion of waste plastics in urban solid waste in China is up to 10 percent. Plastic pollution has become a biggest environmental problem facing human beings, and the plastic star is rejected, so that the plastic pollution is reduced, and the most effective method is to improve the recovery rate of waste plastics and increase the recycling value of the waste plastics. At present, the treatment of plastic garbage mainly adopts modes of landfill, incineration, melting regeneration, thermal cracking conversion and the like. The method has the advantages of simple and convenient landfill, occupying land and polluting soil, realizing the reduction of plastic garbage to a large extent by incineration, causing air pollution in the plastic garbage incineration process, along with simple and convenient fusion regeneration process, having the characteristics of complexity, sand and soil mixing, pollution and the like, being poor in quality and durability of the regenerated plastic products, being converted into new plastic garbage in a short period, being capable of converting the plastic garbage into industrial raw materials or fuel oil with utilization value by thermal cracking conversion, not only eliminating environmental pollution, but also realizing sustainable development and utilization of resources, and being an effective way for treating white pollution. However, the plastic has some problems in the cracking reaction, mainly including poor thermal conductivity, high viscosity of molten materials, easy wall adhesion, carbon deposition and the like. The catalysts widely used in the plastic catalytic cracking at present are molecular sieves (ZSM-5 molecular sieves, Y molecular sieves, USY molecular sieves and the like), activated carbon or metals, and rare earth and the like possibly can be involved. Residuum is the most difficult heavy component to utilize in petroleum, not only the sulfur content is high (more than 2wt% -4 wt%) but also the metal content is more than 200ppm (mainly nickel and vanadium). In order to reduce pollution in the petroleum refining process and improve the profit of oil refining, the hydrogenation of residual oil is converted into petroleum products such as gasoline, diesel oil and the like, which is an optimal production route. The catalyst commonly used in the current residuum hydrocracking is macroporous amorphous silica-alumina loaded active metal, and the macroporous amorphous silica-alumina is used as a porous and high-dispersity solid material, which can provide effective surface and specific pore structure for active components. The co-processing of waste plastics and residual oil is a novel processing mode, but because the physical properties of the waste plastics and residual oil are different, the existing waste plastics conversion catalyst and residual oil conversion catalyst can not realize high-efficiency conversion of two raw materials at the same time, so the development of a catalytic material suitable for the co-conversion of the waste plastics and residual oil is a key for improving the co-conversion efficiency of the waste plastics and residual oil macromolecules. Disclosure of Invention Aiming at the problems and the defects existing in the prior art, the main technical scheme of the invention is to provide a cracking catalyst and a preparation method and application thereof. The cracking catalyst is particularly suitable for the co-conversion process of waste plastics and heavy oil, and can obviously improve the yield of liquid products after use, reduce carbon deposition of the catalyst and prolong the service life of the catalyst. The technical scheme provided by the invention mainly comprises the following aspects: The first aspect of the invention provides a cracking catalyst which comprises a first component and a second component, wherein the first component is a nickel modified ZSM-5 molecular sieve, the second component is amorphous silica-alumina loaded with an active metal component, and the active metal is one or more of group VIB metals, preferably Mo and/or W. Further, in the cracking catalyst, the ratio of the first component to the second component is 1:1-4:1, preferably 2:1-3:1, based on the weight of the plastic and residual