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CN-121988382-A - Composite molecular sieve aromatization catalyst carrier, catalyst and distillate aromatization reaction

CN121988382ACN 121988382 ACN121988382 ACN 121988382ACN-121988382-A

Abstract

The invention provides a composite molecular sieve aromatization catalyst carrier and a catalyst and distillate aromatization reaction. The preparation method of the carrier comprises the steps of carrying out hydro-thermal treatment on an HZSM-5 molecular sieve to obtain the HZSM-5 dealuminated molecular sieve, mixing the HZSM-5 dealuminated molecular sieve, inorganic alkali, zinc-containing compound, thio compound and mesoporous template agent, carrying out hydro-thermal crystallization, filtering, washing, drying and roasting to obtain a modified ZSM-5 molecular sieve, kneading and extruding the modified ZSM-5 molecular sieve, a one-dimensional pore channel molecular sieve, a binder and an extrusion assisting agent to form, and drying and roasting to obtain the composite molecular sieve aromatization catalyst carrier. The invention also provides a catalyst prepared from the carrier, and the distillate oil aromatization reaction catalyzed by the catalyst. The carrier can effectively improve the aromatization activity and shape selectivity of the catalyst and enhance the carbon deposition resistance of the catalyst.

Inventors

  • JU YANA
  • KANG HONGMIN
  • ZHANG RAN
  • GE SHAOHUI
  • WU PEI
  • LV ZHONGWU
  • SONG SHAOTONG
  • LIU KUNHONG
  • ZHANG YALIN
  • CHEN YANFEI

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241101

Claims (20)

  1. 1. A method for preparing a composite molecular sieve aromatization catalyst carrier, the method comprising: step 1, carrying out hydro-thermal treatment and dealumination on an HZSM-5 molecular sieve to obtain the HZSM-5 dealuminated molecular sieve; Step 2, mixing the HZSM-5 dealuminated molecular sieve, inorganic alkali, zinc-containing compound, thio compound and mesoporous template agent, and performing hydrothermal crystallization, filtering, washing, drying and roasting to obtain a modified ZSM-5 molecular sieve; and 3, kneading and extruding the modified ZSM-5 molecular sieve, the one-dimensional pore canal molecular sieve, the binder and the extrusion aid to form strips, and drying and roasting to obtain the composite molecular sieve aromatization catalyst carrier.
  2. 2. The preparation method according to claim 1, wherein in the step 1, the temperature of the hydrothermal treatment is 400-600 ℃, the mass space velocity of the hydrothermal treatment is 0.5-3h -1 , and the time of the hydrothermal treatment is 1-5h.
  3. 3. The preparation method of claim 1, wherein in the step 2, the mass ratio of the HZSM-5 dealuminated molecular sieve, the inorganic base and the zinc-containing compound is 1 (0.05-0.17) (0.14-0.45); The molar ratio of the zinc-containing compound to the thio compound is 0.6-1.
  4. 4. The production method according to claim 1 or 3, wherein in step 2, the zinc-containing compound comprises one or a combination of two or more of zinc acetate dihydrate, zinc nitrate, and zinc sulfate; And/or the thio compound comprises one or a combination of more than two of thioacetamide and ammonium thiosulfate.
  5. 5. The preparation method according to claim 1, wherein in step 2, the mesoporous template agent comprises cetyltrimethylammonium bromide and/or cetyltrimethylammonium chloride; and/or the inorganic base comprises potassium hydroxide and/or alkaline potassium salt.
  6. 6. The preparation method according to claim 1 or 5, wherein in step 2, the molar ratio of the inorganic base to the mesoporous template agent is 0.3 to 1.
  7. 7. The production method according to claim 1, wherein in step 2, the hydrothermal crystallization includes a first crystallization and a second crystallization which are sequentially performed; the temperature of the first crystallization is 100-120 ℃, and the time of the first crystallization is 12-24 hours; the temperature of the second crystallization is 160-200 ℃, and the time of the second crystallization is 12-24 h.
  8. 8. The preparation method of claim 1, wherein in the step 3, the one-dimensional pore molecular sieve comprises one or more of MOR molecular sieve, ZSM-22 molecular sieve, ZSM-23 molecular sieve, ZSM-48 molecular sieve and SAPO-41 molecular sieve.
  9. 9. The preparation method of claim 1 or 8, wherein the mass ratio of the one-dimensional pore molecular sieve to the modified ZSM-5 molecular sieve is 0.1-0.7.
  10. 10. The preparation method according to claim 1, wherein the binder comprises a mixture of pseudo-boehmite, nitric acid and water, and the mass ratio of the dry basis of pseudo-boehmite, nitric acid and water is 1:0.1-0.3:2.3-3.5.
  11. 11. The process according to claim 1, wherein the ratio of the dry mass of the binder to the total mass of the modified ZSM-5 molecular sieve and the one-dimensional channel molecular sieve is (0.1-0.7): 1, and the ratio of the mass of the extrusion aid to the total mass of the dry mass of the binder, the modified ZSM-5 molecular sieve and the one-dimensional channel molecular sieve is 0.01-0.05:1.
  12. 12. A composite molecular sieve aromatization catalyst support obtained by the process of any one of claims 1-11.
  13. 13. The preparation method comprises impregnating a catalyst carrier with a solution of an improved metal auxiliary agent, drying, and roasting to obtain the composite molecular sieve aromatization catalyst; wherein the catalyst support comprises the composite molecular sieve aromatization catalyst support of claim 12.
  14. 14. The production process according to claim 13, wherein the modified metal auxiliary comprises one or a combination of two or more of a group VIII metal salt, a group IIIA salt, and a group IIIB metal salt; The metal salt of the VIII group comprises one or more of cobalt salt, nickel salt and ruthenium salt; The metal salt of the IIIA group comprises one or more than two of gallium salt and indium salt; the group IIIB metal salt includes a lanthanum salt.
  15. 15. A composite molecular sieve aromatization catalyst prepared by the process for preparing the composite molecular sieve aromatization catalyst of any one of claims 13-14.
  16. 16. The catalyst of claim 15, wherein the catalyst comprises a modified ZSM-5 molecular sieve, a one-dimensional pore channel molecular sieve, alumina, a modified metal compound, the modified ZSM-5 molecular sieve comprising elemental zinc; wherein the metal element of the modified metal compound comprises one or more than two of group IIIA metal, group VIII metal and group IIIB metal; The catalyst comprises 50% -80% of silicon dioxide, 6% -16.5% of zinc in oxide and the balance of aluminum oxide, wherein the total weight of the zinc in oxide and the metal elements of the modified metal compound is 100%.
  17. 17. The catalyst of claim 16, wherein the mass of zinc is 2.5% -8% by mass of oxide; The mass of the IIIA group metal is 1% -2%, the mass of the VIII group metal is 1% -2% and the mass of the IIIB group metal is 1% -2% based on the mass of the oxide.
  18. 18. The catalyst of claim 16, wherein the catalyst further comprises potassium oxide, the mass of potassium oxide being 0.7% -2.5%.
  19. 19. The catalyst of claim 15, wherein the catalyst has a specific surface of 180-400m 2 /g, a total pore volume of 0.2-0.4ml/g, a mesoporous volume of 0.1-0.3ml/g, and a mesoporous volume ratio of 60% or more; The total acid amount of the catalyst is 0.08-0.23mmol/g, the strong B acid amount is 0.01-0.1mmol/g, and the L/B molar ratio is 2-10.
  20. 20. The catalyst adopted in the reaction comprises the composite molecular sieve aromatization catalyst of any one of claims 15-19, wherein the technological parameters of the aromatization reaction comprise hydrogen pressure of 1.0-3.0MPa, temperature of 320-420 ℃, airspeed of 1.0-2.0h -1 and hydrogen-oil ratio of 200:1-400:1.

Description

Composite molecular sieve aromatization catalyst carrier, catalyst and distillate aromatization reaction Technical Field The invention relates to the technical field of producing high-octane gasoline components by isomerizing olefin components of catalytic cracking gasoline and aromatizing light components, in particular to a composite molecular sieve aromatization catalyst carrier, a catalyst and a distillate oil aromatization reaction. Background In the aspect of the catalytic cracking gasoline hydroaromatization catalyst, the nano ZSM-5 molecular sieve has excellent aromatization performance due to the characteristics of short pore canal, more pore mouths, small in-crystal diffusion resistance, good thermal stability and the like. However, due to the small aperture (< 0.6 nm), high acid content on the outer surface and the like of the ZSM-5 molecular sieve, the diffusion of reactants and products in pore channels is limited, side reactions such as cracking and polycyclic aromatic hydrocarbon generation are facilitated, condensed oil in the products is increased, the dry point of the products is moved backwards, the gasoline yield is reduced, the aromatization performance and long cycle life of the catalyst are affected, and multiple requirements of greatly reducing olefin, maintaining octane number, controlling distillation range and the like in the quality upgrading process of national VIB standard gasoline are difficult to meet. In particular, about 30 to 40 percent of the olefin composition of the catalytic cracking gasoline is normal olefin, and compared with the isoolefin, the catalyst is more difficult to isomerize and aromatize, the acidity or the reaction severity of the catalyst is required to be improved, and the problems of high cracking activity, deactivation of carbon deposit and the like of the catalyst are caused. How to regulate and control ZSM-5 molecular sieve pore channel structure and acid distribution, increase molecular diffusion, promote normal olefin aromatization reaction, inhibit side reactions such as polycyclic aromatic hydrocarbon generation, and the like, and exert the synergistic effect of the metal active center and the acid center of the catalyst, thus becoming a key technical problem to be solved by the catalyst for the hydrogenation aromatization of the catalytic cracking gasoline. At present, a post-treatment method and a template agent method are mainly adopted to carry out reaming treatment on the ZSM-5 molecular sieve. The post-treatment method mainly comprises a hydrothermal treatment method, an acid treatment method and an alkali treatment method, which are all capable of destroying the framework structure of the molecular sieve, and meanwhile, the obtained mesoporous is irregular and easy to cause the reduction of crystallinity, and the template agent method is expensive, has complex steps and is difficult to industrialize. In the aspect of regulating and controlling the acid distribution of the catalyst to exert the synergistic effect of the metal active center and the acid center, the metal auxiliary agent is often modified by adopting an impregnation method, an ion exchange method, mechanical mixing and the like, so that the problems that the metal auxiliary agent is easily accumulated on the surface of a carrier, a catalyst pore channel is blocked, the accessibility of the acid center and the metal active center in the pore channel is influenced and the like are easily caused. Meanwhile, the prior art mainly focuses on the preparation research of a single molecular sieve aromatization catalyst to improve the aromatization activity, and the aromatization catalyst aiming at a composite molecular sieve is mainly focused on improving the selectivity, so that few reports on how to maximize the utilization of normal olefins to convert the normal olefins into the isoolefins in mixed raw materials and then perform aromatization reaction to synchronously improve the activity and the selectivity are seen. CN112973772a discloses a gasoline aromatization isomerization catalyst and a preparation method thereof. The catalyst comprises 37-85% of nano HZSM-5 grown along 051 crystal face direction, 5-58% of alumina and 2-10% of active metal component. The metal active component is one or more of oxides of VIB group element, VIIB group element, IIB group element, lanthanide, VIII group element and IIIA group element, and the metal active component is loaded by adopting an impregnation method. The catalyst is used for the olefin reduction reaction of the gasoline with high olefin content, can greatly reduce the olefin of the gasoline, and can improve the octane number of the product by 1.7-7 units through the isomerization reaction and the aromatization reaction, the desulfurization rate is more than 45 percent, the yield of the gasoline product is more than 98 percent, and the service life is more than 3000 hours. The patent mainly focuses on regulating and controlling aromati