Method for producing phenol and acetone from cumene

A process to produce phenol and acetone which comprises concentrating the cumene oxidation products up to the point where a residual cumene content of not less than 21wt% is maintained, decomposing the cumene hydroperoxide with sulfuric acid in a homogeneous phenol-acetone-cumene medium in a mixing reactor while maintaining a phenol-acetone-cumene mole ration of 1:1:(0.38-0.61) and subsequently decomposing the dicumylperoxide formed in a plug flow reactor utilizing a phenol-acetone-cumene mole ration of 1: (1-0.77):(0.35-0.87) at a temperature above 150 DEG C with the addition of a cumene fraction and water. The additional cumene fraction contained in the cleavage product passes downstream through the phenol process and into the cleavage product neutralization step and rectification steps where the cumene fraction is recovered by distillation and partially returned to the dicumylperoxide decomposition step. The increased cumene content of the cleavage product stream gives an improved phase separation in the cleavage neutralization step resulting in less than 20 ppm salt and less than 3.5 wt% dissolved water passing downstream into the rectification steps. The overall steam consumption of the process is reduced 0.4-0.6 ton/ton phenol because of less steam requirements to concentrate oxidation products and to remove water from the neutralized cleavage product at the downstream rectification stages. The process is featured by high selectivity, low cumene consumption of 1302-1305 kg/t phenol as well as decreased hydroxyacetone and mesityl oxide by-product formation.