Green synthesis method for preparing alcohol ether by using olefin in one step

Abstract

The invention belongs to the field of organic chemical industry, and provides a green synthesis method for preparing alcohol ether by using olefin in one step. The green synthesis method is characterized in that a jet type reactor is used for continuously jetting alcohol, hydrogen peroxide and a cyclization-alcoholysis catalyst into a pressured reaction kettle filled with olefin gas, so that continuous epoxidation and alcoholysis reaction is carried out; after being separated by a ceramic membrane, reaction liquid enters to an olefin and alcohol removal tower; after olefin and alcohol are removed, the reaction liquid directly and continuously enters to a rectifying tower, and the alcohol ether product is obtained by rectifying; the effective utilization rate of the hydrogen peroxide is more than or equal to 98%, the alcohol ether selectively is greater than or equal to 99%, and the product purity is higher than or equal to 99.5%. The green synthesis method can be used for preparing the alcohol ether in one step and is suitable for industrial large-scale production.

Description

technical field [0001] A green synthesis method for one-step production of alcohol ethers from olefins. The invention provides a green synthesis method for one-step production of alcohol ethers from olefins, and specifically relates to epoxidation and alcoholysis reactions. Background technique [0002] Alcohol ethers currently mainly have two synthesis methods, the first is the direct alcoholysis of alkylene oxide, and the second is the direct epoxidative alcoholysis of olefins. Alcohol ether synthesis At present, more studies mainly focus on the synthesis of propylene glycol methyl ether. [0003] The first direct alcoholysis method of alkylene oxide is that alkylene oxide is subjected to alcoholysis with alcohol at high temperature and high pressure under the action of a catalyst to obtain alcohol ether. In CN92113418.5, modified alumina is used as a catalyst, propylene oxide and methanol are subjected to alcoholysis under the conditions of 90-140°C and 0.7-1.5MPa, the ...

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Problems solved by technology

In CN100556880C, under the conditions of temperature 0-200°C and pressure 0.5-8.5MPa, double fixed-bed reactors are used. In the first fixed bed, propylene and hydrogen peroxide are used as raw materials, methanol is used as a solvent, and titanium-silicon molecular sieve is used as a catalyst to synthesize epoxy Propane, in the second fixed bed, using modified titanium silicon molecular sieve or sodium alkoxide, potassium alkoxide, alkali, etc. as a catalyst, propylene oxide and methanol react, the selectivity of alcohol ether is over 93%, and the conversion rate of hydrogen peroxide is over 98%. This method requires two fixed beds to react in two steps, with many reaction steps, cumbersome operation, high reaction temperature and high pressure.

In CN103012078, TS-1 and metal oxo acid salts / polymetal oxo acid salts are used as catalysts to directly synthesize alcohol ethers from propylene, hydrogen peroxide, and methanol at a temperature of 50 ° C and a pressure of 1.5 MPa. The selectivity of alcohol ethers is over 90%, but The reaction pressure is high, and the conversion rate of propylene is low, only 85%

Chen, Jizhong used toluene as solvent, 1,2-hexene, hydrogen peroxide, and methanol were directly etherified under the catalysis of silicon-containing and tungsten-containing organic catalysts, and reacted at 60°C for 24 hours to obtain alcohol ethers. The catalytic system was complicated and not conducive to industrialization (ChemPlusChem, 80(6), 1029-1037, 2015)

It can be seen that there are generally problems such as high reaction pressure, low conversion rate and low selectivity in the research of one-step synthesis of alcohol ethers from olefins, which is not conducive to industrialization.

[0005] To sum up, the traditional direct alcoholysis of alkylene oxide has the problems of high temperature and high pressure, complex catalyst, and high requirement for alcohol water content, and more than 95% of the raw material alkylene oxide is produced by the chlorohydrin method, which is expensive and seriously pollutes the environment

The one-step synthesis of olefins is the focus of current research on the synthesis of alcohol ethers, but there are generally problems such as two-stage reactions, low conversion rate and selectivity, and olefins, alcohols, hydrogen peroxide, etc. are easily separated in fixed-bed reactors, and the operation is complicated. problems, limiting the further promotion of its industrialization

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