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CN-122006783-A - Modified macroporous mesoporous molecular sieve catalyst, preparation method thereof and application thereof in production of methyl methacrylate

CN122006783ACN 122006783 ACN122006783 ACN 122006783ACN-122006783-A

Abstract

The invention relates to the field of fine chemical engineering, in particular to a modified macroporous mesoporous molecular sieve catalyst, a preparation method thereof and application of the catalyst in methyl methacrylate synthesis reaction. The catalyst comprises a carrier and lanthanum chloride loaded on the carrier, wherein the carrier is a modified macroporous mesoporous molecular sieve, the weight content of lanthanum element in the catalyst is 8% -22%, the weight of the catalyst is 100%, and the surface acid amount of the catalyst is 3-4.5mmol/g. The catalyst provided by the invention is used for the synthesis reaction of methyl methacrylate, and has the advantages of mild operation process conditions, high methacrylic acid conversion rate, high ester selectivity and good catalyst stability.

Inventors

  • LIU HONGMEI
  • SHAO YUN
  • JIANG SHAN
  • LIU DONGBING

Assignees

  • 中国石油化工股份有限公司
  • 中石化(北京)化工研究院有限公司

Dates

Publication Date
20260512
Application Date
20241111

Claims (11)

  1. 1. The catalyst comprises a carrier and lanthanum chloride loaded on the carrier, wherein the carrier is a modified macroporous mesoporous molecular sieve; The weight content of lanthanum element in the catalyst is 8% -22%, calculated by the weight of the catalyst being 100%, and the surface acid amount of the catalyst is 3-4.5mmol/g.
  2. 2. The catalyst of claim 1, wherein: the weight content of lanthanum element in the catalyst is 10% -20%, and the surface acid amount of the catalyst is 3.2-4.2mmol/g based on 100% of the weight of the catalyst, preferably, The weight content of lanthanum element in the catalyst is 13% -18%, and the surface acid amount of the catalyst is 3.5-4mmol/g based on 100% of the weight of the catalyst.
  3. 3. The catalyst according to claim 1 or 2, characterized in that: the catalyst has a specific surface area of 170-420m 2 /g, and/or a pore volume of 0.7-1.6cm 3 /g, and/or an average pore diameter of 6-11nm; Preferably, the catalyst has a specific surface area of 220-370m 2 /g, and/or a pore volume of 0.8-1.4cm 3 /g, and/or an average pore diameter of 7-10nm.
  4. 4. A method of preparing the catalyst of any one of claims 1-3, comprising: 1) The macroporous mesoporous molecular sieve is contacted with concentrated sulfuric acid under the condition of pressurization for reaction, and the obtained solid product is washed and dried to obtain the modified macroporous mesoporous molecular sieve; 2) And (3) carrying out contact reaction on the methanol solution dissolved with lanthanum chloride and the modified macroporous mesoporous molecular sieve, obtaining a solid product after the reaction, and washing and drying to obtain the catalyst.
  5. 5. The method of manufacturing according to claim 4, wherein: The specific surface area of the macroporous mesoporous molecular sieve is 300-500m 2 /g, and/or the pore volume is 1.2-2.0ml/g, and/or the pore diameter is 11-16nm; preferably, the specific surface area of the macroporous mesoporous molecular sieve is 350-450m 2 /g, and/or the pore volume is 1.4-1.8ml/g, and/or the pore diameter is 12-14nm.
  6. 6. The method of claim 5, further comprising the step of preparing a macroporous mesoporous molecular sieve by: In the presence of a template agent and water, mixing and contacting a silicon source, an acid agent, ammonium fluoride and heptane, and sequentially crystallizing, filtering, washing, drying and template removing the mixture obtained after the mixing and contacting to obtain the macroporous mesoporous molecular sieve, wherein the following steps are preferable: the silicon source is at least one selected from ethyl orthosilicate, methyl orthosilicate, propyl orthosilicate, sodium orthosilicate and silica sol, and is preferably ethyl orthosilicate; and/or the acid agent is at least one of hydrochloric acid and sulfuric acid; And/or the template agent is triblock copolymer polyoxyethylene-polyoxypropylene-polyoxyethylene; And/or the molar ratio of the template agent, the ammonium fluoride, the acid agent, the heptane, the silicon source and distilled water is 1 (0.5-6): (150-800): (300-1500): (30-300): (5000-20000); And/or the conditions of the mixed contact include a temperature of 20-60 ℃; And/or the crystallization conditions comprise a temperature of 90-120 ℃ and/or a time of 10-40h; and/or the conditions for the template removal treatment comprise a temperature of 400-600 ℃ and/or a time of 8-50h.
  7. 7. The method of manufacturing according to claim 4, wherein: The modified macroporous mesoporous molecular sieve obtained in step 1) has a specific surface area of 200 to 450m 2 /g, and/or a pore volume of 0.8 to 1.7cm 3 /g, and/or an average pore diameter of 7 to 12nm, preferably, The modified macroporous mesoporous molecular sieve has a specific surface area of 250-400m 2 /g, and/or a pore volume of 1.0-1.5cm 3 /g, and/or an average pore diameter of 8-11nm.
  8. 8. The method of manufacturing according to claim 4, wherein: In step 1): The weight ratio of the large-pore mesoporous molecular sieve to the concentrated sulfuric acid is 1 (0.2-10), preferably 1 (0.5-5), and/or, The conditions of the contact include a temperature of 80-180 ℃ and/or a time of 4-30 hours and/or, The pressurizing conditions include a pressure of 0.2 to 10MPa, preferably 0.5 to 5MPa.
  9. 9. The method of manufacturing according to claim 4, wherein: In step 2): the mass concentration of lanthanum chloride in the methanol solution is 1% -5%, and/or, The weight ratio of the modified macroporous mesoporous molecular sieve to the dosage of the methanol solution is 1 (5-50), and/or, The contact reaction conditions include a temperature of 30-80 ℃ and/or a time of 2-8 hours and/or, The drying conditions include a temperature of 80-150 ℃ and/or a time of 1-20 hours.
  10. 10. Use of the catalyst according to any one of claims 1 to 3 or the catalyst obtained by the process according to any one of claims 4 to 9 in a methyl methacrylate synthesis reaction, wherein the use of the catalyst comprises contacting methacrylic acid and methanol simultaneously with the catalyst.
  11. 11. The use according to claim 10, characterized in that: The conditions of the contact reaction include: The temperature of the contact is 40-150 ℃, preferably 60-120 ℃, and/or the pressure of the contact is 0.01-5.0MPa, preferably 0.1-3.0MPa, and/or the mass space velocity of the methacrylic acid is 0.01-30h -1 , preferably 0.1-10h -1 , and/or the mass space velocity of the methanol is 0.01-50h -1 , preferably 0.1-30h -1 .

Description

Modified macroporous mesoporous molecular sieve catalyst, preparation method thereof and application thereof in production of methyl methacrylate Technical Field The invention relates to the field of fine chemical engineering, in particular to a modified macroporous mesoporous molecular sieve catalyst, a preparation method thereof and application of the catalyst in methyl methacrylate synthesis reaction. Background As an important organic chemical product and an important organic chemical raw material, the industrial production level and the production capacity of Methyl Methacrylate (MMA) have important influence on the development of chemical industry in China. MMA is mainly used in industries such as organic glass (PMMA), paint, textile, adhesive, leather, papermaking, floor polishing, unsaturated resin acidity, methacrylic acid higher esters, wood impregnating compound, printing and dyeing auxiliary agent, plasticizer of plastics and the like. In recent years, the demands of MMA polymers, profiles, plates, coatings, emulsions and the like at home and abroad are increased, the application fields are continuously widened, and the rapid development of MMA industry is promoted. At present, the domestic methyl methacrylate production technology is still in the starting stage. The development of the methacrylate catalyst with independent intellectual property rights and the matched process are the development demands of MMA production industry in China. Esterification catalysts are the core technology for MMA production. The traditional catalyst used to catalyze the esterification of methacrylic acid with methanol is concentrated sulfuric acid. The catalyst has high catalytic activity and low cost, but the characteristics of strong oxidizing property, dehydration property, dissolution of the concentrated sulfuric acid in a reaction system and the like also bring trouble to equipment corrosion and subsequent treatment. Therefore, it is still of positive interest to find a catalyst which combines strong catalytic activity, high selectivity and easy separation from the reaction system. Esterification catalysts for heterogeneous reactions are currently a relatively active area of research. At present, the reported catalyst capable of replacing concentrated sulfuric acid comprises strong acid type ion exchange resin, heteropolyacid, ionic liquid, solid super acid and the like, so that a good effect is obtained. Among them, strongly acidic ion exchange resins have attracted much attention due to their insolubility in the reaction system, good stability, high selectivity, low cost, easy separation, and the like. The strong acid cation exchange resin is a high molecular material containing acidic groups, and is not easy to corrode production equipment because the strong acid cation exchange resin essentially belongs to a solid catalyst, so that the strong acid cation exchange resin has a large application in industrial production. However, the reaction speed of the catalyst is slower, and the yield of the ester is lower. The cation exchange resin has the advantages of good stability, high selectivity, low cost, easy separation and the like in the esterification reaction. However, the cation exchange resin itself has poor heat resistance (generally suitable for esterification reactions at temperatures below 150 ℃), small specific surface area and pore volume, and is susceptible to swelling, and has poor activity and low ester yield when used as an esterification catalyst. Compared with the resin catalyst, the hydrogen zeolite molecular sieve has a certain pore channel structure and surface acidity, and is suitable for catalyzing esterification reaction of small molecules. However, the zeolite molecular sieve has smaller pore canal size (0.5-0.7 nm), can inhibit the diffusion of macromolecular products in the reaction, has smaller number of acid sites on the surface of the zeolite molecular sieve, and has lower efficiency of catalyzing the esterification reaction. With the increasing demand of methyl methacrylate, the environment-friendly synthesis process has wide prospect. For researchers, developing a methyl methacrylate synthesis reaction catalyst with excellent performance, improving the catalytic efficiency and inhibiting the generation of byproducts is an important working direction in the future. Disclosure of Invention The invention aims to solve the problems of low methacrylic acid conversion rate, low methyl methacrylate yield and poor catalyst stability in the existing methyl methacrylate production process, and provides a modified macroporous mesoporous molecular sieve catalyst, a preparation method and application thereof. The catalyst is used for the methacrylate reaction, and can obtain higher methacrylic acid conversion rate, methyl methacrylate selectivity and catalyst stability. The inventors of the present invention found that in the prior art, esterification catalysts for producing methyl methacryl