Method for continuous preparation of epoxypropane

Abstract

The invention discloses a method for continuously preparing epoxy-propane, which is characterized in that a reactant containing propylene and hydrogen peroxide is continuously injected into a reaction system from a feed inlet, the raw powder form titanium silicate molecular sieve as a catalyst and the reactant are mixed uniformly to form slurry for reacting, the molecular sieve and the liquid reactant perform solid-liquid separation in a separation system, the molecular sieve is continuously circulated in a circulation pipeline composed of the reactor and the separation system, and part of liquid product flows out of the reaction system to obtain the objective product. By coupling the reaction and the separation in the method, the liquid product can be effectively discharged from the reaction region in time, the side reaction is reduced, the conversion rate of hydrogen peroxide is higher than 95% and the selectivity of the epoxypropane is higher than 90%.

Description

technical field [0001] The invention relates to a method for producing propylene oxide, more specifically to a method for continuously producing propylene oxide by epoxidation of propylene and hydrogen peroxide in the presence of titanium-silicon molecular sieves. Background technique [0002] Propylene oxide is an important organic chemical raw material, second only to polypropylene and acrylonitrile among propylene derivatives. It is mainly used to produce polyurethane, propylene glycol, polyether polyol, oilfield demulsifier, surfactant, etc. At present, the industrial production of propylene oxide mainly adopts the chlorohydrin method and the co-oxygen method. The disadvantage of the chlorohydrin method is that a large amount of waste water is generated, which seriously pollutes the environment; while the co-oxygen method has a large investment and co-production of other low-cost The question of value-added products. [0003] The discovery of titanium-silicon molecular ...

AI Technical Summary

Problems solved by technology

At present, the industrial production of propylene oxide mainly adopts the chlorohydrin method and the co-oxygen method. The disadvantage of the chlorohydrin method is that a large amount of waste water is generated, which seriously pollutes the environment; while the co-oxygen method has a large investment and co-production of other low-cost The question of value-added products

[0005] Titanium-silicon molecular sieves must be formed when they are used in fixed-bed reactors. The binders added during the forming process have a certain negative impact on the catalytic performance of titanium-silicon molecular sieves. Moreover, the thermal effect of the propylene epoxidation reaction is relatively large, and the formed titanium-silicon Molecular sieve catalysts are not conducive to heat transfer and mass transfer, which is the main cause of catalyst deactivation

In actual production, in order to control the temperature of the catalyst bed, the method of increasing the space velocity is generally used, but this method has high energy consumption and poor economy

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