Method for continuous production of propylene oxide by direct oxidation of propylene with hydrogen peroxide through tubular reactors

Abstract

The invention relates to the field of petrochemical industry, in particular to a method for continuous production of propylene oxide by direct oxidation of propylene with hydrogen peroxide through tubular reactors. The method comprises the steps: a catalyst, namely phosphotungstic acid quaternary ammonium salt is mixed with the hydrogen peroxide and an organic solvent, and the mixture is subjectedto azeotropic dehydration and then sequentially reacts through the multi-stage tubular reactors which are connected in series; and a raw material, namely the liquid propylene is divided into multiplestrands to be parallelly added into all the stages of tubular reactors, reacting mixed liquid flowing out from the tubular reactor of the last stage enters a tower reactor, and after reacting of thereacting mixed liquid in the tower reactor is completed, the reacting mixed liquid enters a separating system. The design is ingenious, through combination of the tubular reactors and the tower reactor and reasonable control over the reacting temperature and the reacting pressure, the atmosphere needing to be protected by N2 in the reactors in a laboratory process is omitted, and condensation filter tower devices which are additionally arranged in the reactors because of protection of the N2 and control over the oxygen content are omitted; the equipment investment and the tail gas treatment cost are saved greatly, tail gas emission of the reactors is less, and thus pollution to the environment is less; and the method has potential market value.

Description

technical field [0001] The invention relates to the field of petrochemical industry, in particular to a method for continuously producing propylene oxide by using a tubular reactor to directly oxidize propylene with hydrogen peroxide. Background technique [0002] Propylene oxide (PO) is an important basic chemical raw material. The traditional production methods in industry are mainly chlorohydrin method and co-oxidation method. The chlorohydrin method will produce a large amount of calcium chloride and chlorine-containing wastewater, which will cause great environmental pollution; Although the oxidation method has less environmental pollution, it has a large investment and a large amount of co-products, and the co-product market will affect the production of propylene oxide. At present, the production of propylene oxide by oxidizing propylene with hydrogen peroxide has gradually become the main direction of the production method of propylene oxide due to less environmental...

AI Technical Summary

Problems solved by technology

[0002] Propylene oxide (PO) is an important basic chemical raw material. The traditional production methods in industry are mainly chlorohydrin method and co-oxidation method. The chlorohydrin method will produce a large amount of calcium chloride and chlorine-containing wastewater, which will cause great environmental pollution; Although the oxidation method has less environmental pollution, it has a large investment and a large amount of co-products. The co-product market will affect the production of propylene oxide

At present, the production of propylene oxide by oxidizing propylene with hydrogen peroxide has gradually become the main direction of the production method of propylene oxide due to less environmental pollution, less co-products, and recyclable catalysts and solvents. However, this method has only completed the laboratory stage now. Research on intermittent production, pilot scale and normal practical continuous production methods and device configurations are still in the development stage

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