Catalytic synthesis method for polyoxymethylene dimethyl ethers (PODE) by molecular sieves

Abstract

The invention relates to a catalytic synthesis method for polyoxymethylene dimethyl ethers (PODE) by molecular sieves, mainly solving the problem of relatively high cost in the conventional method which adopts trioxymethylene as a raw material. In the method, methanol, methylal and paraformaldehyde are adopted as raw materials based on the mass ratio of (0-10): (0-10):1, the raw materials contactwith a catalyst to react and generate PODE, wherein the dosages of the methanol and the methylal can not be zero at the same time; the reaction temperature is 70-200 DEG C; the reaction pressure is 0.1-6MPa; and the adopted catalyst is selected from at least one of beta zeolite, X zeolite, Y zeolite, ZSM-5 molecular sieve, MCM-22, MCM-56, UZM-8 or SAPO-34 molecular sieve. The technical scheme adopted by the invention solves the above problem preferably, thus being applicable to industrialized production of the PODE.

Description

technical field [0001] The invention relates to a method for synthesizing polyoxymethylene dimethyl ether by molecular sieve catalysis. Background technique [0002] In recent years, with the deepening influence of the industrial revolution and my country's unique resource pattern of "more coal, less oil, and gas", my country's oil resources have become increasingly tense, and the pressure on oil supply has increased unprecedentedly. It is estimated that in the next 10 to 20 years, my country's oil supply rate will only be ~50%. How to use our country's rich coal resources to solve our country's energy crisis has become an urgent problem for scientific researchers. Therefore, the development of new oil substitutes from coal-based methanol has attracted increasing attention. [0003] DME was first proposed as a diesel additive. However, due to its poor cold start performance, high vapor pressure at room temperature, and easy air resistance, the cost of DME as an alternative...

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is that in the process of synthesizing polyoxymethylene dimethyl ether with methanol and paraformaldehyde as raw materials in the prior art, there is a problem of high production cost due to the high price of raw material paraformaldehyde, and a new molecular sieve is provided Method for catalytically synthesizing polyoxymethylene dimethyl ether