METHOD OF PREPARING ELECTROINSULATING OIL Russian patent published in 1998 - IPC

FIELD: petroleum refining. SUBSTANCE: petroleum stock is subjected to hydrorefining, catalytic deparaffination and hydrogenation, catalytic deparaffination and hydrogenation being carried out in two reactors consecutively charged with unique system of circulation of water-containing gas which contains hydrogen content within 75-95 vol % at system inlet, and base oil includes 0.2-0.5% antioxidative additive. In order to stabilize quality of transformer oil, base oil is recycled to catalytic deparaffination and hydrogenation stage. Petroleum stock includes petroleum fractions or rafinates of selective refining of sulfur petroleums which evaporate at temperatures from 275-430 C and contain sulfur form 0.1 to 1.0 wt % and aromatic hydrocarbons from 15 to 30 wt %. The method makes it possible to increase yield of quality product and widen raw material basis for preparation thereof. EFFECT: more efficient preparation method. 3 cl, 6 ex, 1 tbl