| 摘要 |
The present invention relates to a method for continuously preparing cyclohexanone from phenol making use of a catalyst comprising at least one catalytically active metal selected from platinum and palladium comprising hydrogenating phenol to form a product stream comprising cyclohexanone and unreacted phenol; 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; separating the second fraction into a third fraction, rich in cyclohexanol, and a fourth fraction, rich in phenol, using distillation; -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 side-products having a higher boiling point than phenol, and phenol; and which method is characterized in the additional step of continuously or intermittently separating at least part of the sixth fraction to yet a further distillation step, thereby forming a seventh fraction and an eight fraction, wherein the seventh fraction is enriched in phenol compared to the eight fraction, and wherein the eight fraction comprises side-products having a higher boiling point than phenol.
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