Process for the purification of cyclohexanone/cyclohexanol mixtures

摘要

In the industrial production of cyclohexanone from cyclohexane by oxidation with gas mixtures containing oxygen, impurities arise which fall in a boiling range between the boiling points of cyclohexanone and cyclohexanol and additionally have a neutral reaction, so that they are very difficult to remove from this cyclohexanol/cyclohexanone mixture in the course of the work-up to give pure cyclohexanone. The subject of the invention relates to separation of such impurities by multi-stage extraction of cyclohexanone and cyclohexanol with water (these impurities being concentrated in the refined product) and the reuse of this aqueous solution in the process without distillation. Very pure cyclohexanone is thus obtained with a very low expenditure on energy and equipment and without additional pollution of the environment by emissions or by high fresh water consumption.