Lubricating oil fraction prepn. for high quality engine base oil - by distilling oil, sepg. vacuum distilling in base for naphthenic acid neutralisation, collecting fraction, extracting prod. contg. furfurol and dewaxing

摘要

The prepn. is from a crude oil a) contg. paraffin solid under ambient conditions and small amts. of naphthenic acid, b) yielding at 369-509 deg.C under vacuum distn., as recalculated to atmospheric press, a LO having a neutralisation No. (DIN51,558, part 1) of 0.1-0.5 mg KOH/g and c) having a viscosity at least 40, (at least 50) (DIN ISO 2,909) after cold deparaffination in presence of a solvent to a pour pt. of -15 deg.C (DIN ISO 3,016). The LO fraction is obtd. by A) distilling the oil under atmospheric pressure with sepn. of a fractoin boiling below 350 deg.C, B) vacuum distilling the distn. residue from A) in presence of bases to neutralise 1-5C and 1-4 OH alkanols to esterify acid components comprising naphthenic acids and collecting the fraction or part fractions contg. LO at 350-550 deg.C, as calculated for atmospheric press, C) extracting the prod. from B) with furfurol conventionally and D) opt. deparaffinating the prod. from C) conventionally. Naphthenic acids are pref. neutralised by addn. of bases esp. aq. lyes to the distn. charge. USE/ADVANTAGE - A furfurol extn. may be without decomposition of the furfurol.