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CN-121988385-A - Supported catalyst and preparation method thereof, and method for preparing monoethylamine and co-producing acetonitrile by using supported catalyst

CN121988385ACN 121988385 ACN121988385 ACN 121988385ACN-121988385-A

Abstract

The invention relates to the technical field of catalysts and ammonolysis reactions, and discloses a supported catalyst and a preparation method thereof as well as a method for preparing monoethylamine and Co-producing acetonitrile by adopting the supported catalyst, wherein the supported catalyst comprises a carrier, and active components and auxiliaries which are supported on the carrier, and is characterized in that the carrier is alumina modified by a SAPO-34 molecular sieve, the active components are Ni and Co, the auxiliaries are Pr and/or Nd, the total content of Ni and Co elements is 15-40wt% based on the total weight of the supported catalyst, the molar ratio of Ni/Co is 1-8.5, and the content of alumina in the carrier is 55-90wt% of the total weight of the carrier.

Inventors

  • TANG GUOQI
  • TIAN BAOLIANG
  • FU SIXIAN
  • SU ZIMU
  • CAI MAO
  • NIU SHU
  • ZHANG LIJUN
  • PENG HUI

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
20260508
Application Date
20241104

Claims (10)

  1. 1. The supported catalyst comprises a carrier, and an active component and an auxiliary agent which are supported on the carrier, and is characterized in that the carrier is alumina modified by a SAPO-34 molecular sieve, the active component is Ni and Co, the auxiliary agent is Pr and/or Nd, the total content of Ni and Co elements is 15-40wt% based on the total weight of the supported catalyst, the molar ratio of Ni/Co is 1-8.5, and the content of alumina in the carrier is 55-90wt% of the total weight of the carrier.
  2. 2. The supported catalyst according to claim 1, wherein the total content of Ni and Co elements is 15-40wt% and the molar ratio of Ni/Co is 3-7 based on the total weight of the supported catalyst; preferably, the total content of Ni and Co elements is 20-35wt%, based on the total weight of the supported catalyst.
  3. 3. The supported catalyst according to claim 1 or 2, wherein the promoter is Nd; And/or, the content of the auxiliary agent is 0.5-3wt% based on the total weight of the supported catalyst.
  4. 4. The supported catalyst of claim 1, wherein the alumina content of the support is 60-85wt% of the total weight of the support.
  5. 5. The supported catalyst of any of claims 1-4, wherein SiO 2 /(SiO 2 +Al 2 O 3 +P 2 O 5 ) in the SAPO-34 molecular sieve is 0.09-0.12, grain size is 1-2 μm, specific surface area >600m 2 /g.
  6. 6. A process for preparing a supported catalyst as claimed in any one of claims 1 to 5, comprising: (1) Modifying the alumina precursor by adopting an SAPO-34 molecular sieve to obtain carrier SAPO-34 molecular sieve modified alumina; (2) And immersing the carrier in a mixed solution, wherein the mixed solution comprises a salt containing an active component and a salt containing an auxiliary agent, wherein the salt containing the active component is nickel salt and cobalt salt, and the salt containing the auxiliary agent is praseodymium salt and/or neodymium salt, so as to obtain the supported catalyst.
  7. 7. The method of claim 6, wherein in step (1), the modification method comprises kneading, extrusion molding, drying and calcining the SAPO-34 molecular sieve, the alumina precursor and the acid solution to obtain the carrier SAPO-34 molecular sieve modified alumina.
  8. 8. The method according to claim 6, wherein in the step (2), the carrier is immersed in the mixed solution and then subjected to drying, calcination and reduction treatment; Preferably, the roasting conditions include a temperature of 150-500 ℃ and a time of 2-6 hours.
  9. 9. A method for preparing monoethylamine and co-producing acetonitrile, which is characterized in that the method comprises the steps of reacting diethyl amine, hydrogen and ammonia through a catalyst bed in the presence of a catalyst to generate monoethylamine and acetonitrile, wherein the catalyst is the supported catalyst of any one of claims 1-5.
  10. 10. The process according to claim 9, wherein the reaction conditions include a reaction temperature of 180-300 ℃ and a reaction pressure of 0.1-10MPa; and/or, the feed liquid phase volume space velocity of diethylamine is 0.05m 3 /(m 3 ·h)-1m 3 /(m 3 h); and/or the molar ratio of hydrogen to liquid ammonia to diethylamine is (0.1-5): (5-100): 1.

Description

Supported catalyst and preparation method thereof, and method for preparing monoethylamine and co-producing acetonitrile by using supported catalyst Technical Field The invention relates to the technical field of catalyst preparation and ammonolysis reaction, in particular to a supported catalyst and a preparation method thereof, and a method for preparing monoethylamine and co-producing acetonitrile by adopting the supported catalyst. Background Monoethylamine, also known as ethylamine, aminoethane, is a colorless liquid, flammable, and volatile with ammonia odor. The water-soluble polymer is arbitrarily mixed with water, alcohol and ether, is used for preparing dyes, rubber accelerators, extractants, emulsifying agents, pesticides, herbicides and mineral processing agents, is also widely used in the production of dyes, surfactants, antioxidants, preservatives and the like, and can also be used for preparing pesticides simazine, atrazine and the like. At present, the synthesis method of monoethylamine mainly comprises an chloroethane ammonolysis method, an acetonitrile hydrogenation method, an ethanol hydro-ammonification method and the like. The byproduct hydrogen chloride in the reaction process of preparing the monoethylamine by the ammonolysis of the chloroethane has the problems of low raw material utilization rate, large amount of chlorine-containing wastewater and salt generation and the like, and has serious environmental pollution, and the process is eliminated. The acetonitrile hydrogenation method is to prepare monoethylamine by liquid phase hydrogenation reduction under the action of metal oxide or Raney nickel and other catalysts by taking acetonitrile as a raw material and ammonia borane or hydrogen as a hydrogen source. However, acetonitrile is expensive, and has limited use, which makes mass production difficult. Compared with other preparation methods, the ethanol hydro-ammoniation method has the advantages that the ethanol raw material is cheap and easy to obtain, the whole reaction process is relatively safe and environment-friendly, the method has more economical efficiency, and the method is almost adopted to produce ethylamine products in China at present. The catalysts commonly used in the process are supported catalysts such as nickel and cobalt, and the like, and the catalysts are balanced catalysts and have good catalytic reaction performance, so that the hydro-ammoniation process ensures that the proportion of various ethylamine products in the reaction products is relatively fixed, the output proportion is basically 2:5:3, and the proportion of diethylamine is higher. However, the market has different requirements for monoethylamine (ETHYLAMINE, chemical formula is C 2H7 N), diethyl amine (DIETHYLAMINE, molecular formula is C 4H11 N) and triethylamine (chemical formula is C 6H15 N), the requirements for monoethylamine and triethylamine are relatively large, and more diethyl amine is produced, and the diethyl amine is required to be separated and then returned to the inlet of the reactor to be mixed with fresh materials and then enters the alcohol ammoniation reactor for a large amount of circulation, so that the product proportion is regulated. CN112691677 discloses a catalyst for preparing ethylamine by hydro-ammonifying ethanol and application thereof, and the data of example 14 show that the product contains monoethylamine, diethyl amine and triethylamine, the proportion of diethyl amine is up to more than 50%, and the proportion of monoethylamine is only 16-17%. CN114315593 discloses a method for producing ethylamine with randomly adjustable product proportion, which uses diethylamine produced in the product to further react with ethanol, ammonia and the like to prepare triethylamine, thereby realizing adjustable ethylamine product proportion. However, the method for recycling the diethylamine product in a large quantity greatly improves the whole energy consumption of the device, reduces the production efficiency of the device, and simultaneously generates more byproducts, so that the subsequent separation is difficult, and the economic and environmental protection pressures are increased. Acetonitrile (chemical formula CH 3 CN or C 2H3 N) is a fine chemical product with wide application, and can be used as extractant, solvent and raw material for synthesizing pesticide. At present, acetonitrile on the global scale is mainly recovered from crude byproducts of acrylonitrile production by ammoxidation of propylene, and the yield is 2-3% of the acrylonitrile yield, and the yield has instability and is relatively high in the yield of an acrylonitrile device. The new production process of acetonitrile is of great interest. At present, the main production technology of acetonitrile comprises acrylonitrile byproduct recovery, acetic acid ammonification dehydration, ethanol dehydrogenation ammonification, monoethylamine dehydrogenation and the like. The recovery of acrylonitrile by