Separation of adipic acid from water-acidic waste of caprolactam production

Abstract

The organic waste generated in the caprolactam production contains a complex mixture of mono- and dicarboxylic acids. It is shown that using two-step oxidation by aqueous hydrogen peroxide allows to isolate adipic acid of high quality. In case if the yield of acids is up to 95% of the nominal value the production of chemicals with high added value can be up to 10 kilotons per year. Retrieving adipic acid from industrial waste will help to solve both economic and environmental issues.

Keywords

• adipic acid, water-acidic waste, concentrate of dicarboxylic acids, oxidation, hydrogen peroxide