Combination treatment of active water washing and solvent extraction for oily sludge
Baiji oil refineries produce 3000–3500 m3 /year of oily sludge. This sludge is hard to be biodegraded, contains large quantities of crude oil, and hard to be transported into landfill sites. The aim of the present work is to treat this oily sludge by solvent extraction in order to separate this sludge to many components that are easy to deal with and recover the valuable crude oil. Different solvents types are used in this work: light naphtha, heavy naphtha, kerosene, gasoline, and methyle ethyle keton. The results show that methyle ethyle ketone gives crude oil extraction efficiency of 95%, solid separation of 24%, and water separation of 94% under 60 oC.