Catalyst for preparing light olefins from synthetic gas and preparation method thereof

Abstract

The invention discloses a preparation method of a catalyst for preparing light olefins from a synthesis gas, and the preparation method comprises the following steps: (1) preparing a mixed solution containing divalent metal cations and trivalent metal cations; (2) dipping silica as a carrier in the mixed solution of the step (1), drying, roasting at 700 DEG C ~ 1000 DEG C for 1h-10h, preferably roasting at 800 DEG C ~ 900 DEG C for 2h-8h; and (3) loading active component iron and metal additives onto the roasted carrier of the step (2), and drying and roasting to prepare the final catalyst for preparing the light olefins from the synthesis gas. The catalyst has the advantages of long-cycle operation activity and high stability, and is conducive to industrial popularization and application.

Description

technical field [0001] The invention relates to a catalyst for producing low-carbon olefins from synthesis gas and a preparation method thereof, in particular to a high-activity and stable loaded iron-based catalyst for producing low-carbon olefins from synthesis gas and a preparation method thereof. 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. So far, the way to produce low-carbon olefins such as ethylene and propylene is mainly through the cracking process of light oil. With the increasing depletion of petroleum resources worldwide, the future energy structure will inevitably shift. Compared with oil resources, coal and natural gas resources are relatively abundant, and it is of great significance to develop low-carbon olefin production processes based on coal and natural gas. The development of direct production...

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Problems solved by technology

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

However, activated carbon as a catalyst carrier not only has poor mechanical strength but also is difficult to shape the catalyst, which affects the service life and stability of the catalyst and is not conducive to industrial applications.

[0004] CN102441383A, CN101940958A, CN102441400A, and CN102441384A respectively use nitrogen-containing organic compound solution, sugar acidic solution, ammonium salt-containing buffer solution, hydrothermal treatment, etc. to impregnate the silica gel carrier to prepare Fe-based silica gel-loaded synthesis gas. Carboolefin Catalysts, Solved Fe and SiO 2 It is easy to produce strong interactions between carriers, which makes it difficult for some Fe to be reduced, and it is difficult to achieve a more ideal reactivity.

However, through further research, it has been found that the above-mentioned Fe-based silica gel-supported synthesis gas directly prepares low-carbon olefins. The activity stability of the long-term operation of the catalyst is not ideal, which seriously affects the application and application of the Fe-based silica gel-supported synthesis gas directly to prepare low-carbon olefins catalysts. to promote

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