Method for preparing epoxypropane

Abstract

The invention relates to a method for preparing epoxypropane. The method comprises the following steps: adding raw materials propylene and oxydol, a solvent methanol and a titanium silicon molecular sieve catalyst into a reaction kettle according to the mole ratio, and regulating the temperature and pressure in the reaction kettle to establish circulation; continuously adding the raw materials and solvent into the pipeline reactor from the outside of the reaction kettle to react, mixing with a static mixer, and sending into the reaction kettle; discharging the reaction mixture from the bottom of the reaction kettle, delivering to a primary heat exchanger through a circulating pump to perform cooling, separating the product epoxypropane and catalyst in a cross-flow filter membrane separator to obtain the product epoxypropane, and returning the trapped catalyst into the reaction kettle via the pipeline reactor, heat exchanger, static mixer and other apparatuses to form the circulation and continue entering into the reaction; and carrying out backflush every other 3-5 hours. The raw materials sufficiently contact the catalyst, the conversion rate of oxydol is at least 96%, and the epoxypropane selectivity is at least 95%. The epoxypropane has stable membrane flux, thereby lowering the membrane pollution, enhancing the product purity and lowering the production cost.

Description

technical field [0001] The invention relates to a method for preparing organic matter, in particular to a method for preparing propylene oxide. Background technique [0002] Propylene oxide (PO) is the third largest propylene derivative except polypropylene and acrylonitrile. It is an important basic organic chemical raw material, mainly used in the production of polyether, propylene glycol, etc., and it is also the fourth generation of detergent non-ionic surface The main raw material of active agent, oilfield demulsifier, pesticide emulsifier, etc. In the prior art, the preparation methods of propylene oxide mainly include chlorohydrin method, co-oxidation method and hydrogen peroxide method. The chlorohydrin method consumes a large amount of chlorine gas, causing serious equipment corrosion and environmental pollution. The co-oxidation method uses the alkyl hydroperoxide produced by the automatic oxidation of ethylbenzene or isobutane as the oxygen source to catalyze th...

AI Technical Summary

Problems solved by technology

The fixed bed reactor is used, the effective contact area between the reaction raw material and the catalyst is small, and the conversion rate of the raw material is low; the catalytic reaction is concentrated on the fixed bed, and the partial temperature is easily generated, causing damage to the reactor, and the reaction risk is high; the catalyst is in operation. It cannot be replaced, and the catalytic efficiency is poor after a long time

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