Patent ID: 6129875
Filing Date: 2000-10-10
Classification: C07C

Abstract:
A method of removing catalyst from a reaction mixture containing one or more dibasic acids, the reaction mixture having been formed after reaction of a hydrocarbon with an oxidant in the presence of the catalyst, water, and a monobasic acid solvent, in an oxidation zone, the method being characterized by steps of:(a) precipitating a major part of the catalyst from the reaction mixture by removing water at least partially and/or controlling temperature to be adequately high for causing catalyst precipitation;(b) removing the precipitated catalyst;(c) further precipitating and removing a major part of remaining catalyst by at least partially removing the monobasic acid solvent and melting the one or more dibasic acids until catalyst precipitates;(d) removing the catalyst which precipitates in step (c) leaving behind a filtrate containing a minor amount of catalyst; and(e) substantially removing from the filtrate the minor amount of catalyst.