METHOD FOR ADIPIC ACID PREPARATION FROM WASTES OF CAPROLACTAM PRODUCTION BY CYCLOHEXANE OXIDATION Russian patent published in 2009 - IPC C07C27/00 C07C55/14 C07C51/16 

FIELD: chemistry.

SUBSTANCE: invention refers to the method of adipic acid production by caprolactam oxidation whereat the row materials are caproloctam-containing waste (pot residue from caproloctam production by cyclohexane hydration) with caproloctam content not less than 90% at temperature 75-100^oC in liquid media. The reaction is carried out with oxidiser being the mixture of 30% hydrogen peroxide taken in amount H₂O₂/caproloctam (1-1.1)/1 mole/mole and concentrated sulphuric acid (96%) taken in amount 0.2-0.36 mole per 1 kg of reaction mass whereof the oxidate is acidified with concentrated sulphuric acid for adipic acid separation.

EFFECT: usage of industrial waste, yield enhancing, absence of difficult-to-separate admixtures in commercial adipic acid.

3 cl, 7 ex, 1 tbl