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CN-121988334-A - Anti-carbon composite metal oxide catalyst and preparation method, regeneration method and application thereof

CN121988334ACN 121988334 ACN121988334 ACN 121988334ACN-121988334-A

Abstract

The invention provides an anti-carbon composite metal oxide catalyst, a preparation method, a regeneration method and application thereof. The catalyst comprises a carrier and a composite metal oxide loaded on the carrier, wherein the composite metal oxide comprises Fe 2 O 3 、K 2 O、MoO 3 、La 2 O 3 、MgO、Tm 2 O 3 、Cs 2 O and NiO. The carbon deposition resistant composite metal oxide catalyst provided by the invention has the characteristics of strong carbon deposition resistance, good dispersibility of active components and high catalytic activity, is simple in preparation process, is easy to regenerate after being deactivated, and is suitable for industrial production of styrene by ethylbenzene dehydrogenation.

Inventors

  • WANG CHENYU
  • MIAO CHANGXI
  • SONG LEI
  • ZENG TIEQIANG
  • ZHU MIN
  • ZHA KAIWEN

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 carbon deposition resistant composite metal oxide catalyst is characterized by comprising a carrier and a composite metal oxide loaded on the carrier, wherein the composite metal oxide comprises Fe 2 O 3 、K 2 O、MoO 3 、La 2 O 3 、MgO、Tm 2 O 3 、Cs 2 O and NiO.
  2. 2. The catalyst according to claim 1, wherein the contents of the components in the composite metal oxide based on the total mass of the composite metal oxide are as follows: a) 66.3% -83% of Fe 2 O 3 ; b) 8% -13% of K 2 O; c) 0.5% -5% of MoO 3 ; d) 0.5% -4.5% of La 2 O 3 ; e) 0.3% -3.2% MgO; f) 0.2% -3% Tm 2 O 3 ; g) 0.2% -3% of Cs 2 O; h) 0.1% -2% of NiO; and/or the number of the groups of groups, The carrier accounts for 49-83 wt% of the catalyst, and the composite metal oxide accounts for 17-51 wt% of the catalyst.
  3. 3. The catalyst according to claim 1 or 2, wherein the support comprises an acid-modified ceria support; Preferably, the specific surface area of the acid-modified cerium oxide support is >60m 2 /g, preferably >95m 2 /g, more preferably 98-110 m 2 /g.
  4. 4. A process for producing a catalyst according to any one of claims 1 to 3, which comprises supporting a composite metal oxide on a carrier by impregnation supporting to obtain the catalyst.
  5. 5. The preparation method according to claim 4, wherein the preparation method comprises the steps of performing a first impregnation treatment on the carrier by using a first impregnation liquid comprising a Fe source, a K source, a La source, a Mg source and a Ni source, drying, performing a second impregnation treatment on the carrier after the first impregnation treatment by using a second impregnation liquid comprising a Tm source, drying, performing a third impregnation treatment on the carrier after the second impregnation treatment by using a third impregnation liquid comprising a Mo source and a Cs source, drying, and roasting to obtain the catalyst.
  6. 6. The method of preparation according to claim 4 or 5, characterized in that the Fe source comprises Fe iron oxide, preferably red iron oxide and/or yellow iron oxide; and/or the K source comprises K salt and/or oxide of K, preferably at least one of potassium carbonate, potassium nitrate and potassium hydroxide; and/or the La source comprises a La salt and/or an oxide of La, preferably lanthanum nitrate; And/or the Mg source comprises Mg salts and/or oxides of Mg, preferably magnesium carbonate; and/or the Ni source comprises a Ni salt and/or an oxide of Ni, preferably nickel nitrate; and/or the Tm source comprises a Tm salt and/or an oxide of Tm, preferably thulium nitrate; and/or the Mo source comprises Mo salts and/or Mo oxides, preferably ammonium molybdate; And/or the source of Cs comprises a Cs salt and/or an oxide of Cs, preferably cesium nitrate.
  7. 7. The method according to any one of claims 4 to 6, wherein the carrier comprises an acid-modified cerium oxide carrier; Preferably, the preparation method of the acid-modified cerium oxide carrier comprises the steps of immersing cerium oxide in an acidic solution, and treating for 10-12 hours at 110-140 ℃; More preferably, the method further comprises the steps of, The mass volume ratio of the cerium oxide to the acidic solution is 0.01-0.02 g/mL; and/or the solute content in the acidic solution is 65-70 wt%; And/or the acidic solution comprises at least one of nitric acid, sulfuric acid, hydrochloric acid, ethylenediamine tetraacetic acid solution, citric acid solution, hydrofluoric acid, hydrogen peroxide and hypochlorous acid.
  8. 8. The preparation method according to any one of claims 4 to 7, wherein the roasting comprises heating to 400 to 450 ℃ at a heating rate of 10 to 15 ℃ per minute, roasting for 40 to 60 minutes, heating to 780 to 850 ℃ again, and roasting for 8 to 12 hours; and/or, the roasting atmosphere is air.
  9. 9. The method for regenerating the catalyst prepared by the catalyst according to any one of claims 1 to 3 or the preparation method according to any one of claims 4 to 8 after the reaction is deactivated, which is characterized by comprising the steps of treating the catalyst deactivated by the reaction in an atmosphere with an oxygen molar content of 3 to 8 percent at 450 to 500 ℃ for 6 to 8 hours, and heating the catalyst to 530 to 570 ℃ for 10 to 13 hours in an air atmosphere to obtain a regenerated catalyst; Preferably, the reactant conversion of the regenerated catalyst is not less than 98% of the reactant conversion of the fresh catalyst, and the product selectivity of the regenerated catalyst is not less than 98% of the product selectivity of the fresh catalyst.
  10. 10. Use of the catalyst of any one of claims 1-3 or the catalyst prepared by the method of any one of claims 4-8 or the regenerated catalyst prepared by the method of regeneration of claim 9 in the dehydrogenation of ethylbenzene to styrene; preferably, the reaction conditions for preparing styrene by ethylbenzene dehydrogenation include a reaction temperature of 590-640 ℃, The reaction pressure is 70-80 kPa, the ethylbenzene space velocity is 1.0-2.0 h -1 , The mass ratio of water to oil is 1.2-2.0.

Description

Anti-carbon composite metal oxide catalyst and preparation method, regeneration method and application thereof Technical Field The invention belongs to the technical field of catalysts, and particularly relates to an anti-carbon-deposition composite metal oxide catalyst, a preparation method, a regeneration method and application thereof. Background Styrene is an organic compound of the formula C 8H8, a colorless, oily liquid with a special aromatic smell, but usually with a weak yellow colour in industrial applications. Styrene is mainly used for the production of polymers and copolymers such as Polystyrene (PS), acrylonitrile-butadiene-styrene (ABS) plastic, styrene-butadiene rubber (SBR), etc. These materials are widely used in consumer products, packaging, construction materials, automotive parts, electrical housings and other industrial products. The production of styrene can be traced back to the early 20 th century. With the development of modern industry, the production technology of styrene has undergone many innovations and improvements. The most widely used process for producing styrene at present is the ethylbenzene direct dehydrogenation process. The ethylbenzene is directly dehydrogenated by converting ethylbenzene to styrene by dehydrogenation, which is typically carried out at elevated temperatures (about 600-650 ℃) in the presence of a catalyst. This process generally has higher selectivity and yield and lower production costs. At present, ethylbenzene conversion can be effectively achieved by using high-performance catalysts, and the conversion rate, styrene selectivity and other indexes are excellent, but challenges and problems still face. For example, as the operating cycle of a styrene unit increases, the catalyst activity will gradually decrease until deactivation, mainly due to carbon build-up and basic nitrogen poisoning. Therefore, the anti-carbon deposition capability of the catalyst for preparing styrene by ethylbenzene dehydrogenation is particularly important. At present, some improved methods can improve the carbon deposition resistance of ethylbenzene dehydrogenation catalysts to a certain extent, but cannot fully meet the requirements of practical application of ethylbenzene dehydrogenation to prepare styrene catalysts. Disclosure of Invention In view of the above analysis, the present invention aims to provide an anti-carbon deposition composite metal oxide catalyst, a preparation method, a regeneration method and an application thereof, which are used for solving the technical problem that a catalyst for preparing styrene by ethylbenzene dehydrogenation in the prior art is easy to deactivate in use. The aim of the invention is mainly achieved by the following technical scheme. In a first aspect, the invention provides an anti-carbon composite metal oxide catalyst, which comprises a carrier and a composite metal oxide supported on the carrier, wherein the composite metal oxide comprises Fe2O3、K2O、MoO3、La2O3、MgO、Tm2O3、Cs2O and NiO. The carbon deposition resistant composite metal oxide catalyst provided by the invention takes the composite metal oxide comprising Fe2O3、K2O、MoO3、La2O3、MgO、Tm2O3、Cs2O、NiO as an active component, wherein a multielement synergistic effect can be formed among potassium ferrate formed by Fe 2O3 and K 2 O, laNiO 3 with a perovskite structure formed by La 2 O and NiO and a solid solution formed by MgO and NiO, so that the uniform dispersion of the active component can be promoted, the induction temperature of the reaction can be reduced, and the activity and the carbon deposition resistance of the catalyst can be effectively improved. According to some embodiments of the present invention, the contents of the components in the composite metal oxide based on the total mass of the composite metal oxide are as follows: a) 66.3% -83% of Fe 2O3; b) 8% -13% of K 2 O; c) 0.5% -5% of MoO 3; d) 0.5% -4.5% of La 2O3; e) 0.3% -3.2% MgO; f) 0.2% -3% Tm 2O3; g) 0.2% -3% of Cs 2 O; h) 0.1% -2% of NiO. According to some embodiments of the invention, the carrier accounts for 49-83 wt% of the catalyst, and the composite metal oxide accounts for 17-51 wt% of the catalyst. According to some embodiments of the invention, the support comprises an acid modified cerium oxide support. In the invention, the acid modified cerium oxide is used as a carrier to form a CeO X structure and oxygen vacancies, so that the concentration of oxygen species on the surface of the catalyst is increased, and the surface carbon species can be oxidized in time, thereby improving the carbon deposition resistance of the catalyst. On the other hand, the acid modification process is favorable for improving the specific surface area of cerium oxide and changing the surface pore structure state of cerium oxide, and is more favorable for uniformly dispersing active components, so that the activity of the catalyst is improved. According to some embodiments of the invention, the specific surface area of