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CN-121988372-A - Catalyst for preparing propylene and butene by ethylene conversion and preparation method and application thereof

CN121988372ACN 121988372 ACN121988372 ACN 121988372ACN-121988372-A

Abstract

The invention discloses a catalyst for preparing propylene and butene by converting ethylene, a preparation method and application thereof. The catalyst for preparing propylene and butene by converting ethylene is a boron modified binderless high-silicon molecular sieve catalyst. The preparation method of the catalyst comprises the following steps of impregnating a non-binder high-silicon molecular sieve catalyst with impregnating solution containing a boron compound, and then optionally drying and roasting to obtain the boron modified non-binder high-silicon molecular sieve catalyst. The catalyst provided by the invention is used in the reaction of preparing propylene and butene by ethylene conversion, has the advantages of high catalytic activity, high propylene butene selectivity, long service life and good stability.

Inventors

  • JIN WENQING
  • TENG JIAWEI
  • ZHAO GUOLIANG
  • REN LIPING
  • LI BIN

Assignees

  • 中国石油化工股份有限公司
  • 中石化（上海）石油化工研究院有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (10)

  1. 1. The catalyst for preparing propylene and butene by converting ethylene is characterized in that the catalyst is a boron modified binderless high-silicon molecular sieve catalyst.
  2. 2. The catalyst according to claim 1, characterized in that the catalyst has a silicon to aluminum atomic ratio of 50 to 1000, preferably 80 to 600; And/or, in the catalyst, the high-silicon molecular sieve is preferably at least one of ZSM-5, ZSM-11, ZSM-23, ZSM-35, beta zeolite and MCM-22, and more preferably ZSM-5.
  3. 3. Catalyst according to claim 1, characterized in that the boron content of the catalyst is 0.1-5.0%, preferably 0.2-1.5%, more preferably 0.3-1.5% by weight of boron oxide.
  4. 4. The catalyst according to claim 1, characterized in that the specific surface area of the catalyst is 200-400 m 2 /g, preferably 280-360 m 2 /g; And/or the pore volume of the catalyst is 0.15-0.3 cm 3 /g, preferably 0.2-0.25 cm 3 /g; and/or the strong acid density of the catalyst is 0.01-0.3 mmol/g, preferably 0.02-0.2 mmol/g; and/or the catalyst has a crystal grain of 0.05-3 μm, preferably 0.1-1 μm.
  5. 5. The method for preparing the catalyst according to any one of claims 1 to 4, comprising the steps of: Impregnating the binderless high-silicon molecular sieve catalyst with the impregnating solution containing the boron compound, and then optionally drying and roasting to obtain the boron modified binderless high-silicon molecular sieve catalyst.
  6. 6. The method according to claim 5, wherein the boron-containing compound is at least one selected from the group consisting of boric acid, ammonium borate and boron trifluoride; and/or the impregnation is carried out by an equivalent impregnation or a solution overdose impregnation method, preferably by overdose impregnation.
  7. 7. The method according to claim 5, wherein the drying conditions comprise a temperature of 80-200 ℃, preferably 100-150 ℃, for a period of 4-48 hours, preferably 8-24 hours; And/or the roasting condition comprises the temperature of 450-650 ℃, preferably 500-600 ℃, and the time of 1-10 hours, preferably 2-8 hours.
  8. 8. Use of a catalyst according to any one of claims 1 to 4 or a catalyst obtainable by a process according to any one of claims 5 to 7 in the conversion of ethylene to propylene and butene.
  9. 9. The use of claim 8 wherein the reaction comprises contacting an ethylene-containing feedstock with the boron-modified binderless high silicon molecular sieve catalyst to produce a product comprising a propylene and butene stream.
  10. 10. The use according to claim 8, wherein the reaction is operated at a temperature of 400-650 ℃, at a pressure of-0.05-1.0 mpa, at a volume space velocity of 500-20000 h -1 , preferably at a temperature of 450-600 ℃, at a pressure of-0.05-0.3 mpa, at a volume space velocity of 1000-10000 h -1 .

Description

Catalyst for preparing propylene and butene by ethylene conversion and preparation method and application thereof Technical Field The invention belongs to the field of petrochemical industry, and particularly relates to a catalyst for preparing propylene and butene by ethylene conversion, and a preparation method and application thereof. Background Propylene is a basic organic chemical raw material, and in recent years, the demand for propylene derivatives such as polypropylene, acrylonitrile, isopropylbenzene, propylene oxide and the like is growing, and particularly, the demand for polypropylene is rapidly growing, so that the propylene consumption is greatly increased in recent years. At present, the main sources of propylene are byproducts of a steam cracking device and byproducts of a catalytic cracking device of a petroleum refinery, but the heavy market demands cannot be met, and the novel propylene production technology at present is continuously emerging, such as continuous construction and production of a large number of propane dehydrogenation and MTO devices. But butene is an important basic chemical raw material, contains four isomers, has very wide application, such as isobutene is used for producing high-octane gasoline additives MTBE and butyl rubber, butene-1 is used as a comonomer for producing polyethylene with different properties and the like, butene-2 is used for producing synthetic rubber raw material butadiene and the like, and the main source of butene is a byproduct of a catalytic cracking device of an ethylene production device and an oil refinery at present. The catalytic cracking dry gas is the byproduct tail gas of the refinery, and contains about 20% of ethylene. Researches show that ethylene can be subjected to oligomerization, cyclization, aromatization, dehydrogenation, hydrogen transfer, cracking and other reactions to generate various products, such as propylene, C4-C8 olefins, alpha-olefins, high-octane gasoline, liquefied gas and other products. At present, the existing dry gas resource utilization technology mainly focuses on the alkylation of dry gas and benzene to produce ethylbenzene and gasoline components and liquefied gas from the dry gas. For example Wang Dianzhong et al (Wang Dianzhong, he Ming Yuan. Petroleum refining and chemical, 26 (1995) 59-63) disclose that the oligomerization of dilute ethylene diluted with nitrogen on ZSM-5 molecular sieves, under the conditions of 0.7MPa pressure, 1h -1 ethylene space velocity and 350 ℃ reaction temperature, gasoline is mostly produced, and when the reaction temperature is lower than 300 ℃, isobutene is mostly produced. CN105985801B discloses a method for promoting catalysis of dry gas to prepare gasoline and liquefied gas, which adopts rare earth modified ZSM-5/ZSM-11 co-crystallized zeolite catalyst to react, so that the conversion rate of ethylene is higher than 90%, the yield of liquefied gas and gasoline is more than 80%, but the yield of propylene is low, and a large amount of process water is needed for the reaction to participate, resulting in high energy consumption. CN105728017a discloses a preparation method of a binder-free ZSM-11 molecular sieve catalyst and is used for catalyzing dry gas ethylene aromatization reaction, the yield of reaction gasoline and liquefied gas is more than 90%, and the reactivity is reduced in 50 hours. The method almost has no propylene generation, and the produced gasoline has high aromatic hydrocarbon content, can only be used as a gasoline blending component, and has poor economical efficiency. The method for preparing propylene and butylene by using ethylene conversion, in particular to high-added-value chemical products of propylene, butylene and other olefins produced by using ethylene conversion in dry gas, not only meets the continuously growing propylene market demand, but also is a good utilization method with maximized resource value, and has good economic and social significance. The method not only can achieve the purpose of high-value utilization of limited resources and alleviate the problem of shortage of chemical raw materials, but also accords with the policy of energy conservation and carbon emission reduction, and has remarkable economic and social benefits. The existing technology for preparing propylene and butylene by ethylene conversion is less, such as: CN102070389a discloses a process for preparing propylene by using refinery carbon four and dry gas as raw materials, by using metal element modified ZSM-5 as a catalyst to react, the propylene yield is about 40%, but the ethylene circulation proportion reaches 70-100%, the carbon four circulation proportion is 67-80%, and the problems of low single conversion rate of raw material ethylene, low reaction efficiency and additional consumption of carbon four products exist. CN101270025A discloses a fluidized bed process, which converts ethylene into propylene by using a molecular sieve as a catalyst under the