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CN-118663314-B - Alkyl transfer catalyst and preparation method and application thereof

CN118663314BCN 118663314 BCN118663314 BCN 118663314BCN-118663314-B

Abstract

The invention discloses a transalkylation catalyst and a preparation method thereof, wherein the transalkylation catalyst comprises a metal hydrogenation component, a modified Beta molecular sieve and a binder, the content of the modified Beta molecular sieve is 30-90 wt% and the content of hydrogenation metal is 0.1-5 wt% based on the weight of the transalkylation catalyst, and the ratio of the acid quantity in micropore channels of the transalkylation catalyst to the acid quantity outside the micropore channels, namely A in /A out , is 100-500, preferably 150-400, and further preferably 200-300. The method comprises the preparation of the modified Beta molecular sieve and the preparation process of the catalyst containing the modified Beta molecular sieve. The alkyl transfer catalyst can obviously reduce side reactions such as aromatic hydrocarbon condensation carbon deposition, aromatic hydrocarbon saturation and the like while improving the xylene yield, and the service life of the catalyst is prolonged.

Inventors

  • ZHANG XUEHUI
  • HAO WENYUE
  • LIU CHANG
  • GUO JUNHUI
  • WANG FENGLAI
  • PENG SHAOZHONG
  • CAO JUNFENG

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
20230314

Claims (20)

  1. 1. The alkyl transfer catalyst is characterized by comprising a metal hydrogenation component, a modified Beta molecular sieve and a binder, wherein the content of the modified Beta molecular sieve is 30-90 wt% based on the weight of the alkyl transfer catalyst, the content of the metal hydrogenation component is 0.1-5 wt%, and the ratio A in /A out of the acid quantity in a micropore duct of the alkyl transfer catalyst to the acid quantity outside the micropore duct is 100-500; The difference between the total acid amount obtained by pyridine infrared and the micropore pore canal external acid amount A out obtained by 2, 6-di-tert-butylpyridine infrared is A in ; the ratio V micro /V meso of the micropore volume to the mesopore volume of the transalkylation catalyst is 0.4-3; The molar ratio A total /M of the total acid amount of the alkyl transfer catalyst to the metal hydrogenation component is 2-10.
  2. 2. The catalyst according to claim 1, wherein the ratio A in /A out of the acid amount in the micropores to the acid amount outside the micropores of the transalkylation catalyst is 150-400.
  3. 3. The catalyst according to claim 1, wherein the ratio A in /A out of the acid amount in the micropores to the acid amount outside the micropores of the transalkylation catalyst is 200-300.
  4. 4. The catalyst of claim 1, wherein the metal hydrogenation component is a noble metal hydrogenation component or a non-noble metal hydrogenation component.
  5. 5. The catalyst of claim 4, wherein the metal hydrogenation component is a non-noble metal hydrogenation component.
  6. 6. The catalyst of claim 4 wherein the non-noble metal hydrogenation component is a non-noble metal of group VIB and/or group VIII.
  7. 7. The catalyst according to claim 6, wherein the group VIB metal is molybdenum and/or tungsten and the group VIII metal is cobalt and/or nickel.
  8. 8. The catalyst of claim 1, wherein the ratio V micro /V meso of micropore volume to mesopore volume of the transalkylation catalyst is 0.5-2.
  9. 9. The catalyst according to claim 1, wherein the molar ratio A total /M of the total acid amount of the transalkylation catalyst to the metal hydrogenation component is 3-6.
  10. 10. A method for preparing a transalkylation catalyst according to any one of claims 1-9, wherein the method comprises the steps of preparing a modified Beta molecular sieve and preparing a catalyst containing the modified Beta molecular sieve, and the method for preparing the modified Beta molecular sieve comprises the following steps: (1) Carrying out inorganic acid treatment on the Beta molecular sieve raw powder from which the template agent is removed; (2) Impregnating the material obtained in the step (1) with a pore canal protective agent solution; (3) Treating the material obtained in the step (2) by adopting macromolecular organic acid; (4) Mixing the material obtained in the step (3) with a dealumination silicon-supplementing reagent, washing, filtering, drying and roasting to obtain a modified Beta molecular sieve; In the step (2), the pore canal protective agent solution is tetraethylammonium hydroxide solution and/or tetrapropylammonium hydroxide solution.
  11. 11. The method of claim 10, wherein in the step (1), the Beta molecular sieve has the following properties of SiO 2 /Al 2 O 3 in a molar ratio of 20-40.
  12. 12. The method according to claim 10, wherein in the step (1), the inorganic acid treatment is performed as follows: and placing the Beta molecular sieve in an inorganic acid solution, stirring, filtering, repeating the process for 2-4 times, washing with deionized water, and drying.
  13. 13. The method according to claim 12, wherein in the step (1), the H+ concentration of the inorganic acid solution is 0.1 to 0.6mol/L.
  14. 14. The method according to claim 13, wherein in the step (1), the H+ concentration of the inorganic acid solution is 0.2 to 0.4mol/L.
  15. 15. The method according to claim 12, wherein in the step (1), the washing is performed for 1 to 5 times until the inorganic acid anion content is less than 0.1wt%.
  16. 16. The method of claim 10, wherein in the step (2), the concentration of the pore-protecting agent solution is 0.2-2.0 mol/L.
  17. 17. The method of claim 16, wherein in the step (2), the concentration of the pore protecting agent solution is 0.4-1.5 mol/L.
  18. 18. The method according to claim 10, wherein in the step (2), the impregnation is an isovolumetric impregnation, and the impregnation treatment temperature is an ordinary temperature.
  19. 19. The method according to claim 10, wherein in the step (3), the macromolecular organic acid is 2, 4-dimethylbenzenesulfonic acid and/or 2, 5-dimethylbenzoic acid.
  20. 20. The method of claim 10, wherein in the step (3), the material obtained in the step (2) is mixed with water, wherein the liquid-solid ratio of the water to the material obtained in the step (2) is 2:1-6:1 mL/g, and then macromolecular organic acid is added until the pH value of the solution is reduced to 5-8.

Description

Alkyl transfer catalyst and preparation method and application thereof Technical Field The invention relates to the field of comprehensive utilization of aromatic hydrocarbon, in particular to a transalkylation catalyst and a preparation method and application thereof. Background Among benzene, toluene, xylene and C9 aromatics, toluene and C9 aromatics have lower added values. In different processes, the contents of toluene and C9 aromatic hydrocarbon account for 40-50% of the total weight of the aromatic hydrocarbon. In order to fully utilize aromatic hydrocarbon resources and increase the added value of products, toluene disproportionation and alkyl transfer technologies are developed, and the technology is widely applied to large-scale aromatic hydrocarbon combined production devices. Toluene disproportionation and transalkylation techniques refer to a process for producing benzene and xylenes from toluene and C9 aromatics as feedstock in the presence of a catalyst comprising a molecular sieve of MFI, MOR or BEA configuration and a hydrogenation metal as the main components, using a fixed bed reactor in the presence of a certain hydrogen pressure. Japanese patent publication No. 51-29131 discloses a catalyst for disproportionation and transalkylation of MoO 3-NiO/Al2O3 toluene, which can obtain a BTX mixed product under the conditions of 6MPa, 550 ℃ and the like. U.S. patent 473028 discloses a toluene disproportionation and transalkylation catalyst using mordenite as the acidic component and supported metals such as Ni or Pd, ag, pt, etc. as the hydrogenation component. CN200610025095.8 discloses a toluene disproportionation and transalkylation catalyst, which comprises 20-90 parts of hydrogen zeolite, 10-80 parts of binder and 0.001-5 parts of platinum oxide, wherein the molar ratio of SiO 2/Al2O3 is 10-100. The catalyst disclosed in the patent has the problems of more aromatic hydrocarbon condensation side reactions, reduced xylene yield, obvious carbon deposition, more aromatic hydrocarbon saturation side reactions and high aromatic loss rate. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a transalkylation catalyst, a preparation method and application thereof. The alkyl transfer catalyst can obviously reduce side reactions such as aromatic hydrocarbon condensation carbon deposition, aromatic hydrocarbon saturation and the like while improving the xylene yield, and the service life of the catalyst is prolonged. The first aspect of the invention provides a transalkylation catalyst, which contains a metal hydrogenation component, a modified Beta molecular sieve and a binder, wherein the content of the modified Beta molecular sieve is 30-90 wt% and the content of hydrogenation metal is 0.1-5 wt% based on the weight of the transalkylation catalyst, and the ratio of the acid content in micropore channels of the transalkylation catalyst to the acid content outside the micropore channels, namely A in/Aout, is 100-500, preferably 150-400, and further preferably 200-300. In the catalyst of the present invention, the metal hydrogenation component may be a noble metal hydrogenation component or a non-noble metal hydrogenation component, preferably a non-noble metal hydrogenation component. The non-noble metal hydrogenation component is a metal of group VIB and/or group VIII, the metal of group VIB is preferably molybdenum and/or tungsten, and the metal of group VIII is preferably cobalt and/or nickel. In the catalyst of the present invention, the ratio (V micro/Vmeso) of the micropore volume to the mesopore volume is 0.4 to 3, preferably 0.5 to 2. In the catalyst of the present invention, the molar ratio (A total/M) of the total acid amount to the hydrogenation metal is 2 to 10, preferably 3 to 6. In a second aspect, the present invention provides a method for preparing a transalkylation catalyst, the method comprising the steps of preparing a modified Beta molecular sieve and preparing a catalyst comprising the modified Beta molecular sieve, wherein the method for preparing the modified Beta molecular sieve comprises the steps of: (1) Carrying out inorganic acid treatment on the Beta molecular sieve raw powder from which the template agent is removed; (2) Impregnating the material obtained in the step (1) with a pore canal protective agent; (3) Treating the material obtained in the step (2) by adopting macromolecular organic acid; (4) Mixing the material obtained in the step (3) with a dealumination silicon-supplementing reagent, washing, filtering, drying and roasting to obtain a modified Beta molecular sieve; Further, in the step (1), the Beta molecular sieve may be a commercially available product or a microporous hydrogen type Beta molecular sieve prepared according to the prior art. The Beta molecular sieve has the characteristics that the SiO 2/Al2O3 molar ratio is 20-40. In the method, in the step (1), the inorganic acid pore treatment process comprises the steps