PURPOSE: To enhance low-temp. fluidity of a lubricating oil to a large extent, by bringing a paraffinic lubricating oil which has been subjected to dewaxing by means of a physicochemical dewaxing process into contact with a microorganism.
CONSTITUTION: A paraffinic lubricating oil which has been subjected to dewaxing by means of a physicochemical process such as solvent or urea dewaxing is added in an amt. of 5W30% V/V to an inorg. salt nitritious culture ground contg. (NH4)SO4, KH2PO4, K2HPO4, MgSO4, etc. and, after the ground is inoculated with a microorganism such as Pseudomonas aeruginosa HT-L-1 (FERM- P No-6165) utilizing and a main carbon source normal paraffin and biologically treated at pH 4W8 and 20W60°C, a lubricating oil is recovered by a method such as centrifugal separation or filtration.
EFFECT: It is possible to lower the pour point of the lubricating oil to about -40°C.
SUZUKI TOMOO
FUKUOKA SEIICHI
NOGAMI SHIYUUJI
HARA SHINICHI
ZENKOKU SEKIYU KOGYO KIYOUDOUK