METHOD OF PREPARING DEMULSIFIER FOR DEHYDRATION AND DESALTING OF WATER-OIL EMULSIONS Russian patent published in 2000 - IPC

FIELD: crude oil treatment. SUBSTANCE: urethane-type demulsifier for high-extent dehydration and desalting of high-viscosity tar oil emulsions. Demulsifier is prepared by interaction of a branched polyether and p-tolylenediisocyanate on heating in presence of starch simultaneously or successively added to reaction mixture. Molar ratio polyether : p-tolylenediisocyanate : starch is 1:(1-2):1. Interaction product is then combined with a straight-chain polyether at weight ratio from 1:4 to 4:1. Resulting mixtures are preferably dissolved in organic solvent. EFFECT: increased dehydration and desalting efficiency with respect to persistent emulsions under low-temperature conditions with simultaneous protection of equipment against corrosion. 2 cl, 3 tbl, 49 ex