GB939613A - Production of phenol - Google Patents

Abstract

A process for production of phenol comprises contacting cyclohexane with molecular oxygen in the presence of a heavy metal oxidation catalyst, e.g. a cerium, manganese and/or cobalt naphthenate at a temperature in the range of 125-180 DEG C. to produce a mixture comprising cyclo-hexanone, cyclo-hexanol and other oxygenated products, separating unreacted cyclohexane and returning the same to the oxidation step, separating a cyclohexanone-cyclo-hexanol fraction from the mixture, and contacting the fraction in the vapour phase with a dehydrogenation catalyst, e.g. platinum on carbon at a temperature in the range of from 225-375 DEG C. to produce hydrogen and a mixture comprising phenol, cyclohexanone and cyclohexanol, separating phenol from the second-mentioned mixture and recycling the residue to the dehydrogenation step. In a modification benzene is hydrogenated, e.g. using a copper catalyst in the presence of a copper activating material such as nickel in the absence of impurities such as lead, bismuth and cadmium, or utilizing traces of chrome oxide or the oxides of cerium, aluminium, thorium and chromium as well as oxides or uranium, manganese, zinc and iron as the copper activator, preferably from 100 DEG C. to 400 DEG C. to produce the cyclohexane and in this case after the dehydrogenation step, hydrogen and a mixture comprising phenol, benzene, cyclohexanone and cyclohexanol is produced, the hydrogen being withdrawn and recycled to the hydrogenation step, the phenol being separated, the benzene being separated and recycled to the hydrogenation step and the residue being recycled to the dehydrogenation step.