Supported Fe-based catalyst for Fischer-Tropsch synthesis reaction and preparation method thereof

Abstract

The invention discloses a supported Fe-based catalyst for Fischer-Tropsch synthesis reaction and a preparation method thereof. The catalyst comprises a carrier, an active component Fe, an additive Cu and an additive K; the mass ratio of the active component Fe to the carrier is 20-60%; the mass ratio of the active component Fe to the additive Cu to the additive K is 100 : (5-10) : (4-12); and the additive Cu and the additive K are uniformly distributed on the surface of the catalyst. The low-content additives Cu and K of the catalyst have modification effect much higher than those of the existing supported Fe-based catalyst. According to the preparation method, as one or multiple non-ionic surfactants are introduced, the non-ionic surfactants are mixed and dissolved with inorganic salt providing the active component to the catalyst, an ultrasonic or microwave method is introduced during impregnation, and both drying condition and roasting condition are improved, modification action of the additives Cu and K to the active component is improved, activity and stability of the catalyst are improved, and service life of the catalyst is prolonged.

Description

technical field [0001] The invention relates to Fischer-Tropsch synthesis technology, in particular to a supported iron-based catalyst for Fischer-Tropsch synthesis and a preparation method thereof. Background technique [0002] Fischer-Tropsch synthesis is the synthesis gas (CO and H 2 ) raw materials are converted into organic hydrocarbons under the action of catalysts, and the reaction products can be further processed to obtain high-quality gasoline, diesel, aviation kerosene and other liquid fuels and other chemicals. Fischer-Tropsch synthesis technology is an effective way to obtain alternative fuels and bulk chemical raw materials. The development of Fischer-Tropsch synthesis catalysts with high activity, high selectivity, and excellent engineering properties is one of the core contents of Fischer-Tropsch synthesis technology research. one. [0003] Fe and Co are ideal Fischer-Tropsch synthesis catalysts that have been verified by industry, and have been successfull...

AI Technical Summary

Problems solved by technology

The research of Anxia et al. showed that the influence of Cu on the catalyst activity and stability was different due to the different catalyst preparation conditions (Journal of Fuel Chemistry and Technology, Vol39, 2011, 212); the research results of Zhao et al. showed that The combination of K in the catalyst with the acidic sites in the "holes" or pores of the support directly weakens the contact between Fe and K, and inhibits the promotion of K in the catalyst (Journal of Molecular Catalysis A: Chemical, Vol286, 2008, 137) ; In the Chinese patent literature CN102649079A, a Fe-based catalyst supported by activated carbon has been reported, and the methane selectivity of the catalyst is greater than 20%, which is obviously high

[0004] In summary, the traditional supported Fe-based catalysts have the following problems in the Fischer-Tropsch synthesis reaction: 1) Cu, the auxiliary agent, is easy to segregate on the surface of the catalyst particles, covering the active sites, weakening the modulation effect on the active components, and reducing the reaction rate. Activity and stability; 2) The auxiliary agent K is easy to combine with the defect site of the support, resulting in the uneven distribution of K on the catalyst surface, the electron-donating effect on the active component is reduced, and the C in the product 5+ Selectivity decreased; 3) CH of the supported iron-based catalyst 4 The selectivity is obviously high; 4) The preparation of traditional supported Fe-based catalysts usually requires multiple impregnation and roasting, and the operation steps are complicated and time-consuming

These shortcomings greatly limit the application of supported iron-based catalysts in the field of industrial Fischer-Tropsch synthesis.