Vn. Chistyakov et al., PRODUCTION OF TRANSFORMER OIL FROM THE SOLAR OIL FRACTION OF YAREGA CRUDE-OIL, Russian journal of applied chemistry, 70(5), 1997, pp. 808-811
A study is made of selective refining of the solar fraction of Yarega
crude oil with N-methyl-pyrrolidone, hydrorefining, and a combination
of selective refining with hydrorefining of the raffinate.