Liquid - phase hydrogenation of phenol operates at temperatures below the
atmospheric boiling point, around 140 – 150 ° C. High selectivity is claimed, over
99% at 90% conversion. In addition, the process needs less catalyst inventory
and is inherently safe .
Today the main route for cyclohexanone manufacturing is liquid - phase
oxidation of cyclohexane. The synthesis involves the formation of cyclohexyl -
hydroperoxide, further converted to cyclohexanone, cyclohexanol and byproducts,
as illustrated by the following scheme: