Method for preparing azodicarbonamide by hydrogen peroxide oxidization method

Abstract

The invention discloses a method for preparing azodicarbonamide by a hydrogen peroxide oxidization method. The method adopts hydrogen peroxide (with the content of more than 50%) as an oxidant, takes industrial bromine as a main catalyst and takes an iron base substance as an auxiliary catalyst to oxidize biurea to prepare the azodicarbonamide. The method disclosed by the invention is simple in process operation; a reaction mother solution can be circularly used; the discharging of three wastes is reduced and the clean and civilized production effect is achieved; and the problems that the environmental pollution, high environment-friendly cost and the like are caused by the fact that chlorine gas is escaped and a lot of byproduct hydrochloric acid is generated in a process of a conventional chlorine introduction method process can be overcome. An azodicarbonamide product produced by the technology is a polygon-prism-shaped strip crystal and is easy to machine and crush; the product gas content is improved by 2-3% when being compared with that of a chlorine introduction method and the product additional value is high; and meanwhile, the process yield is improved by 1-3%.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a method for preparing azodicarbonamide through hydrogen peroxide oxidation. Background technique [0002] Azodicarbonamide (trade name: blowing agent ADC) is the most important hydrazine derivative, which can be used for foaming products such as polyvinyl chloride, polyethylene, polypropylene, neoprene, styrene-butadiene rubber and silicone rubber. The most widely used general-purpose high-efficiency blowing agent. my country is the country with the largest production capacity of blowing agent ADC in the world, and the chlorine oxidation method is generally used in production at present. [0003] Using chlorine gas to oxidize biurea to prepare azodicarbonamide has the advantage of low cost, but the reaction end point is difficult to control, and the amount of chlorine flowing exceeds the standard or the temperature of the feed liquid is too high when passing chlorin...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a hydrogen peroxide oxidation method to prepare azodicarbonamide for the problems of chlorine gas escape and a large amount of by-product hydrochloric acid causing environmental pollution and high environmental protection costs when the existing chlorine gas oxidizes biurea to prepare azodicarbonamide. The method of diformamide, the process of the present invention is simple to operate, and the reaction mother liquor is recycled, reducing the discharge of three wastes, and achieving the effect of clean and civilized production