Method for preparing glycol monoether from ethylene

Abstract

The invention discloses a method for preparing a glycol monoether from ethylene. The method comprises the following step that ethylene, hydrogen peroxide and a low-carbon alcohol directly undergo an epoxidation-ring-opening etherification single-step reaction to produce glycol ether in the presence of a titanium silicate molecular sieve composite catalyst, wherein the titanium silicate molecular sieve composite catalyst comprises a titanium silicate molecular sieve, one or more acidic molecular sieves and resin. The method provided by the invention adopts the titanium silicate molecular sieve composite catalyst, realizes direct fixed bed preparation of glycol ether from ethylene, solves the problems that the prior art utilizes an ethylene epoxidation-oxirane ring-opening etherification two-step reaction to realize glycol ether preparation and thus processes are complex and energy consumption is high, and improves reaction efficiency.

Description

technical field [0001] The invention belongs to a preparation method of ethylene glycol monoether, which is suitable for the catalytic reaction process in which ethylene, hydrogen peroxide and low-carbon alcohol are directly epoxidized and ring-opened etherified to prepare ethylene glycol monoether. Background technique [0002] Since the Italian Enichem company first synthesized the lattice oxygen-selective titania-silicon molecular sieve catalyst TS-1 in 1983, it has become a hot spot in the research of oxidation catalysts due to its excellent oxidation selectivity and mild reaction conditions, and this discovery is regarded as environmentally friendly. A major breakthrough in catalyst development. [0003] Titanium-silicon molecular sieve catalysts play a very important role in the epoxidation of olefins. For the epoxidation of low-carbon olefins, the liquid-phase epoxidation process uses titanium-silicon molecular sieves as catalysts and hydrogen peroxide as the oxidant;...

AI Technical Summary

Problems solved by technology

The conditions for the preparation of ethylene oxide are harsh and a large amount of by-product carbon dioxide is generated, which wastes ethylene resources. At the same time, the production of ethylene glycol and glycol ether requires another process

[0010] In the application of olefin epoxidation, titanium-silicon molecular sieve catalysts exhibit excellent shape-selective catalytic performance. Generally, the smaller the particle size, the higher the catalyst activity and the better the selectivity. In practical applications, the particle size of titanium-silicon molecular sieve catalysts is about 0.1-15.0μm, however, such a small particle size will bring great difficulties to the separation of the catalyst and the product, although various research results on filter materials have been applied in practice, but for the separation of titanium silicon molecular sieve catalysts and products Separation, the resistance generated during filtration does not lie in the size of the pores of the filter material, but comes from the extremely fine catalyst particles occupying and blocking the pores of the formed filter cake, especially the catalyst particles with a particle size of less than 2 μm are the most suitable for filtration. Unfavorable, this results in low production efficiency and also affects the process of industrial application of titanium silicon molecular sieves

The catalyst with small particle size will not only block the pores of the filter cake during filtration, but part of it will be lost from the pores of the filter medium. The general loss rate is about 5% to 8% of the input amount of the catalyst, which not only causes unnecessary consumption of the catalyst, but also enters the product. Further side reactions are caused in the material, leading to an increase in separation costs and affecting product quality

[0011] CN101190876A provides a method for preparing ethylene glycol monoether from ethylene oxide. The technical scheme adopted is to use ethylene oxide and low-carbon aliphatic alcohol as raw materials, and the reaction temperature is 100-300° C., and the reaction pressure is 0.1 ~3.0MPa, the molar ratio of low-carbon aliphatic alcohol and ethylene oxide is 1~5:1, and the reaction time is 30 minutes~8.0 hours, the conversion rate of ethylene oxide is >99%, and ethylene glycol monoether is selected It overcomes the shortcomings of low conversion rate of ethylene oxide and low selectivity of ethylene glycol monoether in the preparation process of ethylene glycol monoether in the past, but still does not fundamentally solve the problem of preparing ethylene oxide from ethylene oxide. Glycol monoether process is complicated (two-step reaction is required), and the problem of high energy consumption

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