Process for preparing bifunctional catalyst for preparing dimethyl ether directly with synthesis gas

Abstract

The invention discloses two methods for directly preparing a bifunctional catalyst of dimethyl ether by synthesis gas. The core principle is to add an active component for methanol synthesis to a methanol dehydration component in an oxalate precipitation mode, for example, the following steps are adopted: a. the active component which can be used as a methanol synthesis catalyst is dissolved into alcohol in a soluble salt mode to prepare a mixed solution A; b. an active component which can be used as a methanol dehydration catalyst is added into the mixed solution A to be stirred to prepare suspension B; and c. an alcoholic solution of oxalic acid is added into the suspension B during the stirring, and a generated oxalate coprecipitate is aged, filtered, dried and finally roasted at a temperature of between 250 and 550 DEG C to prepare the bifunctional catalyst. The methods have simple preparation process, and the prepared bifunctional catalyst has low reaction temperature, high transformation rate of carbon monoxide, and good selectivity of the dimethyl ether.

Description

technical field [0001] The present invention relates to a catalyst for the preparation of dimethyl ether, more specifically to the preparation of a dual-functional catalyst used in the direct preparation of dimethyl ether by a one-step method of synthesis gas, which is composed of a methanol synthesis catalyst and a methanol dehydration catalyst method. Background technique [0002] Dimethyl ether is an important raw material for the production of various chemical products. In the 1980s, many countries in the world developed dimethyl ether as a safe atomization propellant. Freon was banned in the early 1990s, and dimethyl ether was used as an ideal substitute. In recent years, it has been found that it also has extremely good combustion performance and can achieve clean combustion. It is known as the "clean fuel" of the 21st century at home and abroad, so DME has attracted increasing attention internationally. DME was first produced by distillation of by-products in high-p...

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Problems solved by technology

[0008] The technical problem to be solved by the present invention is to overcome the cumbersome and time-consuming preparation process of the dimethyl ether bifunctional catalyst in the prior art, and the high temperature and low carbon monoxide conversion rate when the catalyst is used in the synthesis gas one-step method to prepare dimethyl ether. High, low selectivity of dimethyl ether, etc., provide a catalyst preparation method with simple preparation process, and the catalyst prepared by this method has the advantages of low reaction temperature, high conversion rate of carbon monoxide and good selectivity of dimethyl ether

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