Cyclohexanone production process with modified post-distillation

A process for continuously preparing cyclohexanone from phenol comprising the steps of:

• (a) hydrogenating phenol in the presence of a catalyst comprising at least one of platinum and palladium as a catalytically active metal to form a product stream comprising cyclohexanone and unreacted phenol;
• (b) separating at least part of the product stream, or at least part of the product stream from which one or more components having a lower boiling point than cyclohexanone have been removed, into a first fraction comprising cyclohexanone and a second fraction comprising phenol and cyclohexanol, using distillation;
• (c) separating the second fraction into a third fraction, rich in cyclohexanol, and a fourth fraction, rich in phenol and, using distillation;
• and
• (d) subjecting at least part of the fourth fraction to a further distillation step, thereby forming a fifth fraction and a sixth fraction, wherein the fifth fraction is enriched in phenol compared to the sixth fraction, and wherein the sixth fraction comprises phenol and side-products having a higher boiling point than phenol, and wherein
• step (d) is practiced by carrying out the further distillation step in a vacuum distillation column equipped with trays in a lower part of the further distillation column, and wherein
• the further distillation column includes packing material instead of trays in at least part of an upper part of the further distillation column above a feed inlet thereof, and wherein
• the packing material in at least part of the upper part of the further distillation column has at least a comparable separating efficiency, and provides a reduction of pressure drop by at least 30%, as compared to use of trays in the upper part thereof, under otherwise similar distillation conditions.