Abstract: A process is disclosed for oxidation of pseudocumene to trimellitic acid wherein process residue and bottoms from stripping procedures to recover process solvent are recycled and incorporated in filtrate mother liquor and reinjected into the oxidation reactor at a point in time at least after the first methyl group in the pseudocumene molecule has been oxidized to a carboxy group. Recovery of trimellitic acid is increased, catalyst recovery is increased in a form suitable for immediate recycle to the oxidation reaction, and waste products from the oxidation process are substantially reduced.

Abstract: A lubricant composition is disclosed comprising a major amount of a lubricating oil composition and a minor amount of an overbased detergent-dispersant lubricant additive comprising a reaction product of an alkaline earth metal phenate and an ammonium alkylbenzene sulfonate wherein the phenate and the sulfonate are reacted in the presence of an alcohol of 1 to 4 carbon atoms and said reaction product is stripped to remove ammonia, water and said alcohol.

Abstract: Instead of total base number of about 30 for an alkaline earth metal sulfonate prepared by reacting up to 200 molar excess of alkaline earth metal compound at a temperature above 104.degree. C. with an alkylbenzene sulfonic acid in the presence of from 0.5 to 10 weight parts of water per 1.0 weight part of alkaline earth metal compound under a pressure of from 2 to 10 atmospheres an oil-soluble magnesium-alkylbenzene sulfonate of total base number of 400 and higher is obtained by reacting at least on 8.5 to 1.0 molar ratios of magnesium oxide to ammonium alkylbenzene sulfonate at a temperature of from 100.degree. C. to 130.degree. C. under autogeneous pressure in the presence of at least 1.1 weight parts of water and 0.3 to 0.5 of methanol per weight part of magnesium oxide. After decompressing and removing water and methanol, the product high base number magnesium alkylbenzene sulfonate is obtained.

Abstract: Terephthalic acid (TA) or isophthalic acid (IA) of fiber-grade quality is recovered under oxidation temperature and pressure conditions from fluid oxidation effluent from catalytic liquid phase oxidation of the respective xylene isomer in acetic acid with molecular oxygen by crystal size classification and acetic acid mother liquor displacement with hot, fresh acetic acid followed by quenching the new suspension of phthalic acid crystals in said hot solvent with colder fresh acetic acid solvent and separating the product crystals. Such technique eliminates the need for separately purifying crude TA or IA or converting TA or IA to the respective dimethyl ester and purifying the ester.

Abstract: A process is disclosed for separating the isomers of xylene from a mixture of C.sub.8 aromatic isomers by the steps of:1. cooling the C.sub.8 aromatic isomers to a temperature of about -65.degree.C to about -90.degree.C to form a slurry of xylene isomer crystals,2. separating the crystals from the crystallization mother-liquor and washing the xylene isomer crystals with an immiscible liquid,3. forming a slurry of the washed xylene crystals with the immiscible liquid,4. warming the slurry to a temperature of about -50.degree.C to about -25.degree.C whereby meta-xylene crystals are melted selectively and the melt is drawn off,5. further warming the slurry to a temperature of about -25.degree.C to about 13.degree.C whereby ortho-xylene crystals are melted selectively and the melt is drawn off, and6. separating the remaining para-xylene from the immiscible liquid.For effective separation of the xylene isomers, the immiscible liquid has a freezing point below about -75.degree.C and a specific gravity at -50.