6:vila - Chavez M A, Eustaquio - Rinc6n R, Reza J, et al. Extrac- tion of hydrocarbons from crude oil tank bottom sludges using su- percritical ethane[ J]. Separation Science and Technology,2007, 42(1 ) :2327 -2345.
7Taiwo E A, Otolorin J A. Oil recovery from petroleum sludge by solvent extraction[ J ]. Petroleum Science and Technology, 2009, 27(2) :836 -844.
8Steven R, Heuer, Arvade C. Process for the recovery of oil from waste oil sludges : US ,4990237 [ P ]. 1991 - 02 - 05.
9Humbert H, Chu. Decontamination extraction process for treatment of oily solids : US, 5279747 [ P ]. 1994 - 01 - 18.