CN-121988339-A - Carbon-containing catalyst and preparation method and application thereof

Abstract

The invention provides a carbon-containing catalyst and a preparation method and application thereof, wherein the carbon-containing catalyst comprises, by weight, a) 20-50 parts of iron element or oxide thereof, b) 20-40 parts of at least one of transition elements or oxide thereof, c) 15-25 parts of at least one of IIA group elements or oxide thereof, d) 1-12 parts of at least one of lanthanoid elements or oxide thereof, and e) 2-6 parts of carbon element. The carbon-containing catalyst provided by the invention can be applied to the reaction of producing low-carbon olefin by using synthesis gas, has the advantage of small carbon deposition amount, and has higher low-carbon olefin selectivity.

Inventors

• LI JIANFENG
• PANG YINGCONG
• DAI YIMIN

Assignees

• 中石化（上海）石油化工研究院有限公司
• 中国石油化工股份有限公司

Dates

Publication Date

20260508

Application Date

20241108

Claims (10)

1. 1. The carbon-containing catalyst is characterized by comprising the following components in parts by weight: a) 20-50 parts of iron element or oxide thereof; b) 20-40 parts of at least one of transition elements or oxides thereof; c) 15-25 parts of at least one of group IIA elements or an oxide thereof; d) 1-12 parts of at least one of lanthanoid elements or an oxide thereof; e) 2-6 parts of carbon element.
2. 2. The carbonaceous catalyst according to claim 1, wherein the transition element comprises Mn and/or Mo.
3. 3. The carbonaceous catalyst according to claim 1 or 2, wherein the group IIA element comprises Mg and/or Ca.
4. 4. A carbon-containing catalyst according to any one of claims 1-3, characterized in that the lanthanoid comprises Yb and/or Eu.
5. 5. The method for preparing a carbon-containing catalyst according to any one of claims 1 to 4, comprising the steps of preparing a mixed solution comprising a precursor of a component a, a precursor of a component b, a precursor of a component c and a precursor of a component d, adding a precipitant to the mixed solution, stirring for precipitation, filtering to obtain a mixture, preparing a solution comprising a carbon source, adding the mixture, stirring, vacuum-drying, and calcining in an inert atmosphere to obtain the carbon-containing catalyst.
6. 6. The method of claim 5, wherein the carbon source comprises glucose and/or polyethylene glycol; And/or, the precipitant comprises aqueous ammonia; and/or the inert atmosphere comprises argon.
7. 7. The method of preparation of claim 5 or 6, wherein the component a precursor comprises a soluble salt of iron; and/or the component b precursor is selected from soluble salts of transition elements, preferably from soluble salts of Mn and/or soluble salts of Mo; And/or the component c precursor is selected from soluble salts of group IIA elements, preferably from soluble salts of Mg and/or soluble salts of Ca; And/or the component d precursor is selected from a soluble salt of a lanthanide, preferably from Yb and/or Eu.
8. 8. The production method according to any one of claims 5 to 7, wherein the baking temperature is 400 to 550 ℃ and the baking time is 2 to 6 hours; and/or the temperature of the vacuum drying is 100-120 ℃.
9. 9. Use of the carbonaceous catalyst according to any one of claims 1 to 4 or the carbonaceous catalyst prepared by the preparation method according to any one of claims 5 to 8 in a reaction for producing low carbon olefins from synthesis gas.
10. 10. A method for producing low-carbon olefin by using synthesis gas, which is characterized by comprising the steps of contacting and reacting a raw material comprising the synthesis gas with the carbon-containing catalyst prepared by the preparation method according to any one of claims 1-4 or the carbon-containing catalyst prepared by the preparation method according to any one of claims 5-8 to generate low-carbon olefin; Preferably, the method comprises the steps of, The molar ratio of H 2 to CO in the synthesis gas is 0.5-4; and/or the reaction temperature is 300-500 ℃; and/or the reaction pressure is 0.5-3.5 MPa; and/or the volume space velocity of the raw material gas is 1500-8000 h -1 .

Description

Carbon-containing catalyst and preparation method and application thereof Technical Field The invention belongs to the technical field of catalysts, and particularly relates to a carbon-containing catalyst, and a preparation method and application thereof. Background The process flow for directly producing the low-carbon olefin from the synthesis gas through Fischer-Tropsch synthesis is simple, and the excessive dependence on petroleum resources can be reduced, so that the raw material source is widened for producing the low-carbon olefin. The active component of the catalyst for producing the low-carbon olefin by high-temperature Fischer-Tropsch synthesis is mainly iron, and the addition of additives such as transition metal, alkaline earth metal and the like is beneficial to improving the selectivity of the low-carbon olefin. Fischer-Tropsch synthesis is carried out at high temperature, and side reactions such as CO disproportionation, long-chain hydrocarbon coking and the like are more likely to occur in the reaction process, so that carbon is deposited on the surface of the catalyst. As the reaction time is prolonged, the active sites are gradually covered with carbon deposition, thereby causing a great decrease in catalyst activity and low-carbon olefin selectivity. Disclosure of Invention In view of the above analysis, the present invention aims to provide a carbon-containing catalyst, and a preparation method and application thereof, so as to solve the technical problem that the carbon deposition phenomenon is serious in the use process of the catalyst for the high-temperature fischer-tropsch synthesis reaction in the prior art. The aim of the invention is mainly achieved by the following technical scheme. In a first aspect, the invention provides a carbonaceous catalyst comprising the following components in parts by weight: a) 20-50 parts of iron element or oxide thereof; b) 20-40 parts of at least one of transition elements or oxides thereof; c) 15-25 parts of at least one of group IIA elements or an oxide thereof; d) 1-12 parts of at least one of lanthanoid elements or an oxide thereof; e) 2-6 parts of carbon element. According to some embodiments of the invention, the iron oxide is Fe 3O4. According to some embodiments of the invention, the transition element comprises Mn and/or Mo. According to some embodiments of the invention, the group IIA element comprises Mg and/or Ca. According to some embodiments of the invention, the lanthanoid comprises Yb and/or Eu. In a second aspect, the invention provides a preparation method of the carbon-containing catalyst in the first aspect, which comprises the steps of preparing a mixed solution comprising a component a precursor, a component b precursor, a component c precursor and a component d precursor, adding a precipitant into the mixed solution, stirring, precipitating and filtering to obtain a mixture, preparing a solution comprising a carbon source, adding the mixture, stirring, vacuum drying and roasting in an inert atmosphere to obtain the carbon-containing catalyst. In the invention, by roasting in inert atmosphere, the volatilization of C element caused by oxidation into CO or CO 2 can be avoided, so that the C element can be reserved in the prepared catalyst. According to some embodiments of the invention, the carbon source comprises glucose and/or polyethylene glycol (PEG). In the invention, glucose and polyethylene glycol are used as carbon sources, and compared with other types of carbon sources, the catalyst has better effect on improving the carbon deposition phenomenon of the catalyst. In the invention, the molecular weight of polyethylene glycol does not have obvious influence on the performance of the prepared catalyst, and various common types of polyethylene glycol can be selected as a carbon source. According to some embodiments of the invention, the precipitant comprises aqueous ammonia. According to some embodiments of the invention, the inert atmosphere comprises argon. In the invention, the inert atmosphere is argon, which is more favorable for the formation of active crystalline phases of the catalyst and enhances the interaction between the active components and the auxiliary agent compared with other inert atmospheres, thereby being favorable for improving the catalytic performance of the catalyst. According to some embodiments of the invention, the component a precursor comprises a soluble salt of iron, such as ferric nitrate. According to some embodiments of the invention, the component b precursor is selected from soluble salts of transition elements, preferably from soluble salts of Mn and/or soluble salts of Mo, such as manganese nitrate, ammonium heptamolybdate. According to some embodiments of the invention, the component c precursor is selected from soluble salts of group IIA elements, preferably from soluble salts of Mg and/or soluble salts of Ca, for example magnesium nitrate, calcium nitrate. According to some embodi