Adipic Acid

Abstract

Cyclohexane is oxidised by air in a series of three reactors, endothermically at l650C and 10.5 bar in the presence of boiler acid to produce a mixture of cyclohexanone and cyclohexanol, called ketone-alcohol (KA) oil. Overhead gases are condensed to remove most of the contained cyclohexane from N2, CO and CO2. KA oil is oxidised to adipic acid using nitric acid in a two stage reaction system operating at 700C and lOOC respectively. Total residence time is one and a half hours. Crude product is crystallised producing 95 percent adipic acid after centrifuging. This is recrystallised, dried and bagged.