Patent ID: 6239309
Filing Date: 2001-05-29
Classification: C07G,C10M

Abstract:
A process for using sludge formed in the preparation of a high BN overbased alkylaryl sulfonate, wherein said sludge is separated from said high BN overbased alkylaryl sulfonate, and wherein said sludge comprises high BN overbased alkylaryl sulfonate, alkaline earth metal salt, alkaline earth metal base, and other impurities, said process comprising:(a) passing said sludge through a phase separation system to form a lower density fraction of high BN overbased alkylaryl sulfonate and reduced levels of alkaline earth metal salt, alkaline earth metal base, and other impurities, and a higher density fraction having increased levels of said alkaline earth metal salt, alkaline earth metal base, and other impurities;(b) treating said lower density fraction with an acidic reactant to reduce the average particle size of the alkaline earth metal salt in the lower density fraction, wherein at least one equivalent of acidic reactant is used for each equivalent of alkaline earth metal salt of the lower density fraction; and(c) reacting said treated lower density fraction with an excess of alkaline earth base to produce a reaction product containing additional high BN overbased alkylaryl sulfonate and additional sludge.