A kind of silica gel carrier and its preparation method and application

Abstract

The invention discloses a silica gel carrier. The silica gel carrier comprises, by weight, 0.1 to 0.5% of titanium, and 0.5 to 2% of iron; pore volume of the silica gel carrier ranges from 0.5 to 3cm<3> / g, average pore diameter ranges from 8 to 15.0nm, and specific surface area ranges from 200.0 to 350.0m<2> / g. The invention also discloses a preparation method of the silica gel carrier. The preparation method comprises following steps: (1) an inorganic acid and a titanium-containing compound solution are added into a silicate solution in a manner of parallel flow until pH value of an obtained reaction system reaches 10.5 to 12, and the reaction system is kept at a constant temperature for 1 to 3h; (2) an iron-containing compound solution and an inorganic acid are added into a material obtained via step (1) until pH value of an obtained mixture reaches 8.5 to 9.5, and the mixture is kept at a constant temperature for 1 to 6h, and then is heated to 70 to 120 DEG C for 3 to 10 hours of aging; and (3) a product obtained via step (2) is washed, dried and roasted so as to obtain the silica gel carrier. The silica gel carrier is suitable to be used as a catalyst carrier used for direct low-carbon olefin production from synthetic gas; and a prepared catalyst possesses high activity, stability and selectivity.

Description

technical field [0001] The invention relates to a silica gel carrier and its preparation method and application, in particular to a modified silica gel carrier suitable for direct production of low-carbon olefins from synthesis gas, its preparation method and application. 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 of ethylene and propylene te...

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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, the above method adopts immersion treatment methods such as ammonium salt-containing buffer solution, sugar solution, nitrogen-containing organic compound solution, etc., which not only increases the cost of the catalyst, but also easily causes the environment and changes the physical properties of the silica gel carrier, affecting the stability.