Preparation method and applications of catalyst used for preparing light olefin from synthesis gas

Abstract

The invention relates to a preparation method and applications of a catalyst which is used for preparing light olefin from synthesis gas directly and co-preparing gasoline. The preparation method comprises following steps: a molysite is taken as a precursor, and then the catalyst is obtained by pre-treatment with a carbon source, dispersion-mixing and modified vapor deposition which are all simple and easy to operate, wherein an iron-containing compound is taken as the active center of the catalyst, and the catalyst can be used for direct conversion of synthesis gas to light olefin and co-preparing of gasoline. Catalytic activity and economic cost of the catalyst enable that the catalyst can be applied in industrial production.

Description

technical field [0001] The invention belongs to the fields of energy and chemical industry, and relates to a preparation method and application of a catalyst for directly producing low-carbon olefins and co-producing gasoline by using synthesis gas as a raw material. Specifically, the present invention relates to the preparation of a supported solid iron-based catalyst for a gas-solid phase catalytic reaction system, and the application of the catalyst in the direct production of light olefins and co-production of gasoline with syngas as raw material. Background technique [0002] Low-carbon olefins such as ethylene and propylene are important basic organic chemical raw materials. With the development of the chemical industry, their demand is increasing. At present, the production of light olefins mainly adopts the petrochemical route of naphtha or light oil cracking. With the increasing depletion of oil resources around the world, the future energy structure is bound to sh...

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Problems solved by technology

[0003] CN1065026A discloses a method for producing ethylene from synthesis gas. The catalyst is prepared by chemical precipitation and mechanical mixing, using precious or rare metals, such as niobium, gallium, praseodymium, scandium, indium, cerium, lanthanum, ytterbium, etc. Elements, the selectivity of ethylene is 65%-94%, but the conversion rate of CO is low, only about 10%, 12% and 15%, the recycling of CO increases energy consumption, and the catalyst cost is high

The combined technique of laser pyrolysis combined with solid-state reaction prepared Fe m C n The main Fe-based nanocatalyst has high catalytic activity, CO conversion rate greater than 96%, high content of ethylene and propylene in the gas phase product, low methane content, and no high-carbon hydrocarbon generation, but the preparation process of the catalyst is cumbersome and the preparation cost is high

[0005] CN1083415A discloses a K + or Cs + Iron-manganese catalyst is an improved Fischer-Tropsch synthesis catalyst, which can obtain low-carbon olefins in a higher yield, but the preparation of the catalyst is complicated, the reaction temperature is high, and the selectivity of methane in the product is high

However, the catalyst has poor mechanical strength and is difficult to form, which affects the service life and stability of the catalyst and does not make use of industrial applications.

[0007] The above catalytic systems have made good progress in the direct production of light olefins from syngas, but there are still the following problems: low conversion rate of syngas; poor product selectivity, which reduces the utilization efficiency of syngas; high catalyst preparation cost, Complicated preparation or poor reproducibility

The problem to be solved by the catalyst is to control the selectivity of light olefins and the conversion rate of CO

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