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CN-122010131-A - Composite molecular sieve of MFI or beta configuration molecular sieve and AEI configuration molecular sieve, and manufacturing method and application thereof

CN122010131ACN 122010131 ACN122010131 ACN 122010131ACN-122010131-A

Abstract

The invention relates to a composite molecular sieve of an MFI or beta configuration molecular sieve and an AEI configuration molecular sieve, a manufacturing method and application thereof. The method for manufacturing the composite molecular sieve comprises the steps of providing a first molecular sieve containing a first template agent, and then manufacturing a second molecular sieve in the presence of a second template agent and the first molecular sieve containing the first template agent, so as to obtain the composite molecular sieve, wherein the first template agent and the second template agent are different in chemical structure, and the first molecular sieve is at least one selected from an MFI configuration molecular sieve and a beta configuration molecular sieve, and the second molecular sieve is an AEI configuration molecular sieve. The composite molecular sieve material of the invention is used as a catalyst, and has higher ethylene and propylene yields in the cracking reaction of C 5 -C 10 normal paraffins and the catalytic cracking reaction of naphtha.

Inventors

  • LI SIJIE
  • XU HUIQING
  • SONG ZHAOYANG
  • LIU QUANJIE
  • WANG YANG

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
20260512
Application Date
20241111

Claims (19)

  1. 1. A method of making a composite molecular sieve comprising the steps of: 1) Providing a first molecular sieve comprising a first template (such as making the first molecular sieve comprising a first template in the presence of the first template), and then 2) Producing a second molecular sieve in the presence of a second template and the first molecular sieve comprising the first template to obtain the composite molecular sieve, Wherein the first template is chemically different from the second template and the first molecular sieve is selected from at least one of an MFI-configured molecular sieve and a beta-configured molecular sieve (preferably selected from at least one of a ZSM-5 molecular sieve and a beta molecular sieve), and the second molecular sieve is an AEI-configured molecular sieve (preferably a SAPO-18 molecular sieve).
  2. 2. The manufacturing method of claim 1, wherein in step 1), there is also present a silicon source, an aluminum source, an alkali source, and water, wherein the silicon source: the aluminum source: the alkali source: the first template R comprises water in a molar ratio of SiO 2 :Al 2 O 3 :OH - :R:H 2 0=1:0.01-0.1:0.02-2:0.03-2:5-60 (preferably SiO 2 :Al 2 O 3 :OH - :R:H 2 0=1:0.01-0.05:0.02-2:5-60), and/or in step 2) there is also present a silicon source, an aluminum source, a phosphorus source and water, wherein the molar ratio of the silicon source to the phosphorus source to the second template D comprises SiO 2 :Al 2 O 3 :P 2 O 5 :D:H 2 0=0.01-2:1:0.1-2:0.5-5:20-100 (preferably SiO 2 :Al 2 O 3 :P 2 O 5 :D:H 2 0 =0.03-1:1:0.5-1.5:1-3:20-100）, and/or the total mass ratio of the first template comprising first molecular sieve to the phosphorus source of step 2) is (55-99): 1, preferably (65-99): 1, and/or the first template comprising first molecular sieve comprises first template is an average particle size of 85% to 60% by weight percent, preferably by weight percent of the first template is not more than 60% and/or the second template is preferably 70% by weight percent of water, the total mass ratio of the first template comprising first template is preferably 5 to 60% by weight percent of water, the total mass ratio of the first template is preferably 5-100% to the total mass ratio of the silicon source, the aluminum source and the phosphorus source is preferably (55-99): 1, and/or the average of the first template is preferably 60% by weight percent of the silicon source, the average particle size of the first template is preferably 60% to the average particle size of the first template is 60% by weight of the average particle size of the first sieve is 60% and the average particle size of the first sieve is 60) is preferably weight of the average particle size of the particle size is water, and the average particle size is water is total particle size is water, and the average is water is weight, and is water is weight is water is water is, the loss rate of the first templating agent is less than 10wt% (preferably less than 5wt% or less than 2 wt%).
  3. 3. The manufacturing method according to claim 1, wherein the first template agent and the second template agent are capable of forming hydrogen bonds or ionic bonds with each other in the presence of water, and/or the first template agent is capable of being used for synthesizing the first molecular sieve, and/or the first template agent is selected from at least one of ethylenediamine, triethanolamine, tetrapropylammonium hydroxide, N-butylamine, ethylamine, 1, 6-hexamethylenediamine, tripropylamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, tetraethylammonium fluoride, triethylamine, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, polyvinyl alcohol, sodium carboxymethyl cellulose, preferably from at least one of ethylenediamine, triethanolamine, and/or the second template agent is capable of being used for synthesizing the second molecular sieve, and/or the second template agent is selected from at least one of N, N-diisopropylethylamine, tetraethylammonium hydroxide, triethylamine, N-methyl 3, 5-dimethylpiperidine, preferably N, N-diisopropylethylamine.
  4. 4. The manufacturing method of claim 1, wherein in step 1), the step 1) comprises the steps of: 1-1) mixing a silicon source, an aluminum source, an alkali source, a first templating agent, and water to form a first mixture, 1-2) Crystallizing said first mixture to produce said first molecular sieve comprising a first templating agent, 1-3) Isolating the first molecular sieve comprising the first template (preferably, optionally after filtration, drying (particularly spray drying) the first molecular sieve comprising the first template).
  5. 5. The production process according to claim 4, wherein in step 1-2), the crystallization conditions include a crystallization pressure of from atmospheric pressure to system autogenous pressure, the presence or absence of seed crystals, a crystallization temperature of from 130 to 220 ℃ and preferably from 150 to 180 ℃ and a crystallization time of from 24 to 96 hours and preferably from 48 to 96 hours, and/or in step 1-3), the drying conditions include a drying temperature of from 60 to 120 ℃ and preferably from 65 to 110 ℃ and a drying time of from 5 to 20 hours and preferably from 8 to 15 hours and/or the spray drying conditions include a solid content of from 35 to 65%, an inlet air temperature of from 150 to 250 ℃, an outlet air temperature of from 80 to 150 ℃ and an air velocity of from 300 to 1500m 3 /h and/or further comprising, after the step 1-3), pulverizing (such as grinding) the first molecular sieve containing the first template agent to an average particle size of 85% or more and passing through 60 mesh and preferably 90% or more.
  6. 6. The method of manufacture of claim 1, excluding a step capable of removing a portion or all of the first template from the first molecular sieve comprising the first template, and/or, wherein the step 1) does not include a calcination step.
  7. 7. The manufacturing method of claim 1, wherein the step 2) comprises the steps of: 2-1) mixing a silicon source, an aluminum source, a phosphorus source, a second templating agent, and water to form a second mixture, 2-2) Mixing said first molecular sieve comprising a first templating agent with said second mixture to obtain a composite mixture, 2-3) Optionally drying said composite mixture, crystallizing said composite mixture to produce said composite molecular sieve, 2-4) Optionally washing and/or optionally filtering, and drying the composite molecular sieve.
  8. 8. The manufacturing process of claim 7, wherein in step 2-2) the first molecular sieve comprising the first template is finely divided (e.g., sprayed) with the second mixture, and/or in step 2-2) the morphological integrity (particularly the bulk structure or the pore structure) of the first molecular sieve comprising the first template is substantially maintained after the mixing.
  9. 9. The production method according to claim 7, wherein in step 2-3) the composite mixture is dried, the crystallization conditions include a crystallization pressure of from atmospheric pressure to a system autogenous pressure, a mass ratio of dry gel powder to water of 1 (0.2-0.7), preferably 1 (0.3-0.5), the upper and lower parts are placed together in a hydrothermal autoclave, a crystallization temperature of 130-220 ℃ and preferably 150-180 ℃, a crystallization time of 24-96 hours and preferably 24-72 hours, and/or in step 2-3) the drying conditions include a drying temperature of 50-160 ℃ and preferably 60-120 ℃, a drying time of 0.1-20 hours and preferably 0.5-12 hours, and/or in step 2-4) the drying conditions include a drying temperature of 80-150 ℃ and preferably 85-130 ℃ and a drying time of 5-20 hours and preferably 8-15 hours.
  10. 10. The method of claim 7, further comprising the step of calcining the composite molecular sieve after the step 2-4), wherein the conditions of the calcining include a calcining temperature of 500-750 ℃ under an oxygen-containing atmosphere (preferably 550-700 ℃) and a calcining time of 5-20 hours (preferably 8-15 hours).
  11. 11. The manufacturing process of claim 1, wherein in step 1) the first molecular sieve comprising the first template is substantially not removed after manufacture and/or in step 2) the morphological integrity (in particular the bulk structure or the pore structure) of the first molecular sieve comprising the first template is substantially maintained under the manufacturing conditions of the second molecular sieve and/or in step 2) the second molecular sieve is grown in situ on the first molecular sieve comprising the first template.
  12. 12. A composite molecular sieve comprising a first molecular sieve and a second molecular sieve covering the surface of the first molecular sieve, wherein the first molecular sieve is selected from at least one of an MFI-configured molecular sieve and a beta-configured molecular sieve (preferably selected from at least one of a ZSM-5 molecular sieve and a beta molecular sieve), the second molecular sieve is an AEI-configured molecular sieve (preferably a SAPO-18 molecular sieve), and the mass ratio of the first molecular sieve to the second molecular sieve is (60-99): 1, preferably (70-99): 1.
  13. 13. The composite molecular sieve of claim 12, wherein the first molecular sieve has an average particle size of 85% or more passing 60 mesh (preferably 90% or more passing 100 mesh).
  14. 14. The composite molecular sieve of claim 12, wherein the first molecular sieve and the second molecular sieve are substantially interpenetrated, and/or the XRD spectrum of the composite molecular sieve is substantially the same as that of the first molecular sieve, and/or the composite molecular sieve has a bimodal pore distribution, and/or the pore distribution of the composite molecular sieve has a most probable pore size of 0.38-0.45nm (preferably about 0.42 nm) and 0.50-0.75nm (preferably 0.55-0.70 nm), respectively, and/or the pores of the composite molecular sieve having a most probable pore size of 0.50-0.75nm account for more than 80% (preferably about 90%) of the total pore volume, and/or the composite molecular sieve has a BET specific surface area of 400-650m 2 /g (preferably 400-600m 2 /g), and a pore volume of 0.30-0.70ml/g (preferably 0.30-0.60 ml/g).
  15. 15. The composite molecular sieve of claim 12, producible according to the production method of any one of claims 1 to 11.
  16. 16. A catalytic cracking catalyst obtained by subjecting the composite molecular sieve according to claim 12 to ion exchange treatment.
  17. 17. The catalytic cracking catalyst as claimed in claim 16, wherein the conditions of the ion exchange treatment (single time) include an ammonium salt solution concentration of 1-2mol/L, a solid-liquid mass ratio of the composite molecular sieve to the ammonium salt solution of 1 (10-30), a reaction temperature of 60-100 ℃ and a reaction time of 1-3 hours.
  18. 18. A catalytic cracking process comprising the step of catalytically cracking a C 5-10 normal alkane or naphtha to produce a C 2-4 alkene in the presence of the catalytic cracking catalyst of claim 16.
  19. 19. The catalytic cracking process according to claim 18, wherein the conditions of catalytic cracking include nitrogen as a carrier gas, a nitrogen flow rate of 30-50ml/min, a reaction temperature of 500-700 ℃ and a feed space velocity of 2-5h -1 .

Description

Composite molecular sieve of MFI or beta configuration molecular sieve and AEI configuration molecular sieve, and manufacturing method and application thereof Technical Field The invention belongs to the technical field of petrochemical industry, and particularly relates to a composite molecular sieve of an MFI or beta configuration molecular sieve and an AEI configuration molecular sieve, a manufacturing method thereof and application thereof in preparing olefin by catalytic cracking. Background The low-carbon olefin is an important basic organic chemical raw material. At present, the production route of the low-carbon olefin in China mainly comprises naphtha pyrolysis, including steam pyrolysis, catalytic pyrolysis and other processes. Compared with steam cracking with higher energy consumption cost, the catalytic cracking technology reduces the reaction temperature, increases the range of the available raw materials, realizes flexible regulation and control of product distribution, improves economic benefit and has wider application prospect. Most of catalytic cracking reactions use molecular sieves as catalysts, acidic active sites in the molecular sieves crack raw materials into small molecules, and micropore channels perform further shape-selective actions on the small molecules to generate target products such as ethylene, propylene and the like. Common molecular sieve catalysts include Y-type molecular sieves, beta-type molecular sieves, ZSM-type molecular sieves, SAPO-type molecular sieves, and the like. However, the single molecular sieve catalytic material has single pore size, so that the acidity property is not completely matched with the pore structure, and the mass transfer of reactants and products in the pore channels of the molecular sieve is limited, thereby influencing the service life of the catalyst and the selectivity of target products. Research shows that the composite molecular sieve prepared by combining two or more molecular sieves shows excellent catalytic performance compared with a single molecular sieve in catalytic cracking reaction. The acidic properties and pore channel structures among different molecular sieves in the composite molecular sieve are blended, so that the purposes of enhancing the pore channel domain limiting effect and improving the reaction activity can be achieved. For example, in CN118289775A, a Y molecular sieve is used as seed crystal to prepare a composite molecular sieve of 5-20wt% of Y molecular sieve with high silicon-aluminum ratio and 20-60wt% of modified ZSM-5 molecular sieve, two different acid centers are utilized to convert hydrocarbon in crude oil into small molecular hydrocarbon, and then the small molecular hydrocarbon is cracked into target products such as ethylene, propylene and the like. The composite molecular sieve has strong acid active center and hierarchical pore structure in proper proportion, and can promote the efficient conversion of hydrocarbon molecules with different structures. CN104549467A synthesizes a Y/ZSM-5 catalytic cracking composite catalyst in situ, can lighten diffusion limitation, and strengthen adsorption and desorption capacity and selectivity, thereby improving catalytic cracking reaction activity and ethylene propylene yield. Wherein, the conversion rate of naphtha is 3-5% higher than that of the catalyst prepared by the prior art, and the yield of diene is 2-5% higher than that of the catalyst prepared by the prior art. The CN101190418A adopts a template agent which is simultaneously suitable for synthesizing a ZSM-5 molecular sieve and mordenite to prepare the ZSM-5/mordenite composite molecular sieve, has the characteristics of smaller crystal grains and larger specific surface area, shows higher reactivity, and has better catalytic performance because the pore canal in the crystal is shorter and carbon deposition can be prevented, and the total yield of ethylene and propylene can reach 55.0 percent. Most of the preparation methods of the composite molecular sieves disclosed in the prior art are mechanical mixing methods or eutectic growth methods, and the pore channel structures still need to be adjusted although the two molecular sieve properties can be effectively combined together. Firstly, aiming at the size of the diameter of the raw material molecules, the two molecular sieves do not fully exert the synergistic catalytic effect of the two molecular sieves, effectively limit the products to small molecular olefins such as ethylene, propylene and the like, and secondly, the pore channels of the two molecular sieves are not connected to form a through pore structure, so that the diffusion efficiency among the pore channels is greatly limited, the limiting field effect of the pore channels of the molecular sieves is weakened, and macromolecular products are easily generated or secondary cracking reaction occurs to increase carbon deposit. Therefore, the invention synthesizes a composite molecular sieve