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CN-122010134-A - Composite molecular sieve of MFI or beta configuration molecular sieve and CHA configuration molecular sieve, and manufacturing method and application thereof

CN122010134ACN 122010134 ACN122010134 ACN 122010134ACN-122010134-A

Abstract

The invention relates to a composite molecular sieve of an MFI or beta configuration molecular sieve and a CHA configuration molecular sieve, a manufacturing method thereof and application thereof in preparing olefin by catalytic cracking. The method for manufacturing the composite molecular sieve comprises the following steps of 1) providing a first molecular sieve containing a first template agent, and then 2) 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 a CHA 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
  • SONG ZHAOYANG
  • XU HUIQING
  • 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 a CHA-configured molecular sieve (preferably a SAPO-34 molecular sieve).
  2. 2. The production method according to claim 1, wherein in step 1) there is also present a silicon source, an aluminum source, an alkali source and water, wherein the molar ratio of the aluminum source to the alkali source to the first template R to water is 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 = 1:0.01-0.05:0.02-2:0.03-2:5-60), 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 aluminum source to the phosphorus source to the second template D to water is 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 = 0.03-1:1:0.5-1.5:2-4:20-100）, and/or the total mass ratio of the first molecular sieve containing the first template to the silicon source, the aluminum source and the phosphorus source of step 2) is (55-99:1), preferably (65-99:1) and/or the first template to the second template D is less than 5% by weight percent (preferably) of the first template to the first template) to the total mass ratio of the first template c is less than 5% (preferably 5% by weight percent, the first template) to the total mass ratio of the first template D to water is preferably SiO 2 :Al 2 O 3 :P 2 O 5 :D:H 2 0 = 0.03-1:1:0.5-1.5:2-4:20-100）, and/or the total mass percent of the first template D to the second template D is less than 5% by weight percent (preferably 5% to the first template) to the total weight percent of the first template) is less than 5% to the total weight percent of water is preferably less than 5% by weight percent of water (preferably 5% of the first template) to the total weight percent of water is less than 5% of water).
  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 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 triethylamine, n-butylamine, isobutylamine, isomerised dipropylamine, diisopropylamine, tripropylamine, tetraethylammonium hydroxide, morpholine, preferably triethylamine.
  4. 4. The manufacturing method of claim 1, wherein 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 normal pressure to system autogenous pressure, presence or absence of seed crystals, a crystallization temperature of 130-220 ℃ and preferably 150-180 ℃ and a crystallization time of 24-96 hours and/or in step 1-3), the drying conditions include a drying temperature of 60-120 ℃ and preferably 65-110 ℃ and a drying time of 5-20 hours and preferably 8-15 hours and/or in step 1-3), the spray drying conditions include a solid content of 35-65%, an inlet air temperature of 150-250 ℃, an outlet air temperature of 80-150 ℃ and an air velocity of 300-1500m 3 /h and/or further comprising pulverizing (such as grinding) the first molecular sieve containing the first template to an average particle size of 85% or more passing through 60 mesh and preferably 90% or more passing through 100 mesh after the step 1-3).
  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 400-650 ℃ in an oxygen-containing atmosphere (preferably 450-600 ℃) 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-configured molecular sieve), the second molecular sieve is a CHA-configured molecular sieve (preferably a SAPO-34 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 CHA 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 a CHA configuration molecular sieve, a manufacturing method thereof and application thereof in preparing olefin by catalytic cracking. Background The low-carbon olefin such as ethylene, propylene and the like is an important petrochemical product and is also an indispensable basic chemical raw material. The continuous development of the low-carbon olefin industry not only drives the rapid development of a plurality of different industries, but also influences national economy and daily life of people. In 2021, the ethylene yield of China is 3747 ten thousand tons, the consumption is 5832 ten thousand tons, the propylene yield is 4297 ten thousand tons, the consumption is 4538 ten thousand tons, and the low-carbon olefin is still in short supply. And the contradiction between supply and demand is more and more intense along with the gradual increase of the demand of low-carbon olefin in China. At present, the production route of the low-carbon olefin in China mainly comprises naphtha pyrolysis, including steam pyrolysis, catalytic pyrolysis and other processes. The steam cracking technology in China is very mature, and large-scale, serial and modularized production is realized, but the steam cracking technology has the defects of high reaction temperature, high energy consumption, large influence on olefin yield by raw materials, poor selectivity on target products and the like, and severely limits the further development of the technology. Compared with steam cracking, 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 wide application prospect. The catalytic cracking reaction mostly uses molecular sieves as catalysts, such as Y-type molecular sieves, beta-molecular sieves, ZSM-series molecular sieves, SAPO-series molecular sieves and the like, and the pore channel structure and the acidic property of the molecular sieves jointly determine the performance of the catalytic cracking reaction. The traditional molecular sieve has single pore diameter, limited mass transfer in the reaction and easy occurrence of coking phenomenon, thereby influencing the service life of the catalyst and the selectivity of target products. The composite molecular sieve is used as a catalytic material with multiple molecular sieve performances, and the purposes of enhancing the pore canal limiting effect and improving the reaction activity can be achieved by blending the acidic property among the molecular sieves and the pore canal structure. CN103055929a discloses a method for preparing low-carbon olefin by using MCM-41 and ZSM-5 composite molecular sieve. And mixing an aluminum source, a silicon source and a template agent, hydrolyzing and aging, uniformly mixing the aged liquid with a silicon source and hexadecyl trimethyl ammonium bromide (CTAB) aqueous solution, and crystallizing to obtain the MCM-41 and ZSM-5 mesoporous/microporous composite molecular sieve. The molecular sieve catalyst loaded with the active metal component is applied to the naphtha catalytic cracking reaction, and the yield of ethylene and propylene can reach 29 percent. CN112657547a discloses a method for preparing low-carbon olefin by using a phosphorus-containing multi-stage pore ZSM-5/Y composite molecular sieve. The preparation method of the molecular sieve comprises the steps of adding the Y molecular sieve into a mixed solution of alkali liquor, an organic template agent and deionized water, gradually adding a silicon source and a boron source in batches under sufficient stirring, and performing thermal crystallization on the obtained mixed solution to obtain the ZSM-5/Y composite molecular sieve. After the molecular sieve is modified by the phosphorus-containing compound, the yield of ethylene and propylene can reach 58.1 percent. CN108273546a discloses a method for preparing propylene catalyst by catalytic pyrolysis of naphtha. And uniformly stirring silica sol, a template agent, deionized water and an EU-1 molecular sieve, crystallizing, and carrying out ammonium exchange to obtain the hydrogen EU-1/ZSM-5 composite molecular sieve, wherein the yield of C 2+C3 of the catalyst for catalytic cracking of the composite molecular sieve by naphtha loaded by tetrabutylammonium perrhenate is more than 87%. Most of the preparation methods of the composite molecular sieve disclosed in the prior art are mechanical mixing methods or eutectic growth methods, which are applied to catalytic cracking reactions, and although the conversion rate and t