Preparation method of catalyst for directly synthesizing dimethyl ether from synthesis gas

Abstract

The present invention relates to a preparation method of a catalyst for directly synthesizing dimethyl ether from synthesis gas, wherein the problems of high catalyst synthesis cost and low dimethyl ether selectivity in the prior art are mainly solved through the preparation method of the present invention. According to the preparation method of the present invention, inorganic salts of Cu, Zn and Al are adopted as a methanol synthesis active component raw material, an HY molecular sieve, alpha-Al2O3, or an H-ZSM-5 molecular sieve is adopted as a methanol dehydration active component, a low carbon alcohol is adopted as a solvent, a silica sol, an alumina sol or white carbon black is adopted as a binder, a method selected from rotary evaporation, spray drying method and flash evaporation is adopted to dry, the obtained powder is calcined, then is added with graphite or cellulose ether and other processing aids, and is subjected to extrusion forming to prepare catalyst particles, and calcination is performed again so as to prepare the catalyst. According to the present invention, the catalyst production process is simple, the catalyst has characteristics of high activity, good selectivity, excellent activity at high space velocity, and high dimethyl ether time space yield, and the preparation method can be used for the industrial production of direct preparation of the dimethyl ether from the synthesis gas.

Description

technical field [0001] The invention relates to a preparation method of a catalyst for directly synthesizing dimethyl ether from synthesis gas. Background technique [0002] DME is a simple organic ether compound. It is a colorless gas with a slight fragrance under normal temperature and pressure. Currently, it is mainly used as spray paint, hair spray, air freshener and vehicle atomizer. In addition, DME is also a clean energy, which can be used as automobile and domestic fuel. DME fuel has the advantages of high efficiency, environmental friendliness, safe use and wide application, and has broad industrial prospects. [0003] At present, there are two-step and one-step methods for the production of dimethyl ether. The two-step process is to convert the syngas to methanol and then dehydrate the methanol to dimethyl ether. The one-step synthesis of dimethyl ether is a new technology developed in recent years, that is, a bifunctional catalyst is used, which includes methan...

AI Technical Summary

Problems solved by technology

However, the catalyst activity of mechanical mixing is poor, and the coprecipitation method introduces Na + ions, need multiple washes, complex preparation process, poor reproducibility

Gel impregnation method, using anhydrous ethanol, n-propanol or isopropanol as solvent, the solubility of oxalic acid in ethanol or propanol is low, the amount of alcohol is high, the precipitate needs to be filtered and washed with alcohol, and then dried, the process is complicated and costly high