A method of processing the reaction mixture from the oxidation of cyclohexane

摘要

The reaction mixture containing cyclohexanone, cyclohexanol and adipic acid produced by the oxidation of cyclohexane in the liquid phase with oxygen containing gas is processed by separating the aqueous phase containing dicarboxylic acids from the cooled reaction mixture, washing the organic phase with dilute aqueous alkali hydroxide or carbonate, under conditions which are sufficiently gentle to neutralize only the dissolved organic acids without bringing about a saponificaton of the esters of cyclohexanol, separating this organic phase by distilation into cyclohexane, a mixture of cyclohexanol and cyclohexanone, and a distillation residue of high boiling cyclohexanol esters, saponifying this residue with aqueous alkali, separating the resultant cyclohexanol by azeotropic distillation and returning it into the process. Adipic acid is crystallized from the aqueous phase of the reaction product and recovered by further cooling. The alkali used for saponification may be separated from the residue and then used for the alkali wash.