Process for producing phenol and cyclohexanone

A process for making phenol and cyclohexanone, the process comprising:

• (A) contacting benzene and hydrogen with a catalyst under hydroalkylation conditions to produce a first effluent comprising cyclohexylbenzene;
• (B) oxidizing at least part of the cyclohexylbenzene in the first effluent to produce a second effluent comprising cyclohexylbenzene hydroperoxide;
• (C) cleaving at least part of the cyclohexylbenzene hydroperoxide in the second effluent stream to obtain a product mixture comprising phenol and cyclohexanone;
• and
• (D) separating the product mixture by
• (a) feeding to a distillation column a charge comprising (i) at least a portion of the mixture, (ii) a solvent including at least two alcoholic hydroxyl groups attached to non-adjacent saturated carbon atoms, and (iii) at least one hemiketal defined by one the formulae (I), (II), and/or at least one enol-ether derived from the hemiketal defined by the formula (I) or the formula (II):
• wherein R1, the same or different at each occurrence, is independently a branched or straight-chain alkylene group having from 2 to 10 carbon atoms, R2 is a branched or straight-chain alkylene group having from 4 to 10 carbon atoms, and R3 is hydrogen or the following group:
• and
• (b) distilling at least a portion of the charge in the distillation column.