Extractive distillation of phenol-containing mixtures

Claim 1

A CONTINUOUS PROCESS FOR THE PURIFICATION OF PHENOL IN A MIXTURE CONTAINING PHENOL AND A COMPOUND SELECTED FROM THE CLASS CONSISTING OF CYCLOHEXANOL AND CYCLOHEXANONE WHICH COMPRISES INTRODUCING SAID MIXTURE TO DISTILLATION INTO THE LOWER SECTION OF A FRACTIONATION COLUMN, INTRODUCING WATER INTO SAID COLUMN AT A POINT IN THE UPPER SECTION THEREOF SO THAT SAID WATER FLOWS COUNTERCURRENTLY TO THE RISING VAPORS OF SAID MIXTURE, SAID WATER BEING PRESENT IN AN AMOUNT SUCH THAT THE CONCENTRATION OF WATER IN THE LIQUID BELOW THE POINT OF ADDITION OF THE WATER IS AT LEAST 50 VOLUME PER CENT, WITHDRAWING OVERHEAD FROM THE COLUMN AN AZEOTROPE OF SAID COMPOUND WITH WATER, CONDENSING SAID AZEOTROPE TO FORM A WATER PHASE AND AN ORGANIC PHASE, RETURNING THE WATER PHASE TO THE COLUMN FOR RE-USE AS AN EXTRACTANT, RECOVERING THE ORGANIC PHASE, AND REMOVING FROM THE BOTTOM PORTION OF THE COLUMN A WATER SOLUTION OF SUBSTANTIALLY PURE PHENOL.