Method for preparation of dimethyl ether

Abstract

The invention relates to a method for the preparation of dimethyl ether, which comprises the steps of: using the intermediate product of a copper-zinc-aluminum methanol synthesis catalyst, i.e. the carbonate mixture, as the component of the methanol synthesis catalyst, using rare earth modified gamma-alumina with low temperature activity as the component of the methanol synthesis catalyst, sufficiently mixing the two components according to the method based on colloidal sedimentation and mechanical mixing, and activating the mixture to obtain dimethyl ether. The method of the invention is simple in process and ensures the repeatability in catalyst preparation; the catalyst prepared according to the method has small particle size and high specific surface area; and the catalyst has high activity owing to tight contact and strong synergistic effect between the components.

Description

technical field [0001] The present invention relates to a kind of catalyst preparation method, more specifically, relate to a kind of preparation method of dimethyl ether catalyst. Background technique [0002] Dimethyl ether is a chemical product with a wide range of uses, and it has many unique functions in pharmaceuticals, pesticides, fuels, and daily chemical products. Traditional uses include replacing halogenated hydrocarbons in propellants, environmentally friendly refrigerants, and aerosols. Studies in recent years have shown that DME can also be directly used as fuel as a substitute for liquefied petroleum gas and diesel. With the development of the coal-to-olefins industry, DME can also be used as an important raw material for the production of low-carbon olefins. Therefore, the potential market of DME is very huge. [0003] The original process of methanol dehydration to dimethyl ether is mature. In recent years, a lot of research has been done on catalysts fo...

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Problems solved by technology

However, in the above patents, the reaction temperature is above 250°C

[0004] In the prior art, in the catalyst prepared by mechanical mixing, the contact between the two components is not close enough, the synergistic effect is poor, and the catalyst performance is low; the catalyst prepared by impregnation and co-deposition method, due to the influence of co-deposition method on temperature, acid-base, etc. There are strict requirements on the temperature and drop rate of the solution, and the particle size of the methanol dehydration catalyst also has strict requirements. After deposition, the catalyst needs to be fully washed, the preparation process is relatively complicated, and the repeatability of each batch of catalysts is relatively poor, which cannot meet the needs of industrial production. ; and the reaction temperature is high, the methanol synthesis catalyst component and the methanol dehydration catalyst component cannot be in the optimum condition at the same time