Method for reducing ammoximation COD

Abstract

The invention relates to a method for reducing ammoximation COD. The method has main characteristics that ammoximation waste water is pretreated with added alkali in a stripping column process, wherein alkali is subjected to a reaction with waste water in a waste water stripping column, such that the pH value of the waste water delivered into a waste water column is controlled at 10-13; organic matters in waste water are decomposed; and COD and ammonia nitrogen in waste water are reduced, wherein COD content is reduced from approximately 5000 to below 3000, and ammonia nitrogen is reduced from more than 100 to below 100. According to the invention, no other reaction device is needed, and original devices are not updated. With the method provided by the invention, treatment is carried out at the source, such that indexes of the waste water are reduced to a treatment range, and no secondary pollution is caused.

Description

Technical field [0001] The invention relates to a method for reducing COD of ammoximation. In particular, it is a method for partially reducing the COD and ammonia nitrogen of the ammoximation device itself. Background technique [0002] Caprolactam is a monomer of synthetic fibers and engineering plastics, and has always been an important chemical raw material in short supply in my country. At present, the production of caprolactam mostly adopts the process route of converting cyclohexanone into cyclohexanone oxime and rearranging into caprolactam. Among them, the conversion from cyclohexanone to cyclohexanone oxime is the traditional hydroxylamine salt oximation method. There are many intermediate steps, the process is complicated, and a large number of corrosive and polluting raw materials are used, which causes great harm to the environment. Therefore, in addition to improving the existing processes, the major caprolactam producing countries in the world are actively develo...

AI Technical Summary

Problems solved by technology

[0003] With the increasing demand of the caprolactam market, the ammoximation unit has attracted more and more attention, but the environmental protection of the ammoximation unit is a focus of everyone’s attention. The COD and ammonia nitrogen of the ammoximation unit have been at a high level for a long time Within the control range of the system, there is a great pressure on the wastewater treatment sent to the back. Although the wastewater of the ammonia oximation unit is not much, it has a high destructive effect on the microorganisms in the biochemical system and can cause a large number of microorganisms to die. ; Therefore, it is imperative to reduce the COD and ammonia nitrogen of the ammoximation unit itself