Patent ID: 8618334

Claim:
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.