Removal of Oil from SZ36-1 Simulated Oil Sands Using Sophorolipid Biosurfactant

Abstract

Abstract The sophorolipid biosurfactant was used to remove the oil from the SZ36-1 simulated oil sands. The effects of the sophorolipid concentration, the mass ratio of sophorolipid solution to oil sands (liquid/solid ratio), and the extraction time on the oil extraction efficiency were investigated. Based on the single-factor tests, the optimum results were obtained under the conditions of sophorolipid solution concentration to be 100 mg·L−1, the liquid/solid ratio to be 50:1 and the extraction time to be 2 h. The corresponding oil extraction rate from oil sands reached up to 42%, which was comparable to the result from 2.5 g·L−1 chemical surfactant of sodium dodecyl sulfate (the value of 2.5 g·L−1 was higher than its critical micelle concentration). The oil extraction rate of crude oil with sophorolipid solution was almost not affected by the existence of sodium chloride. The sophorolipid biosurfactant has high surface activity and good oil removing capacity, and is expected to replace the synthetic surfactants to be used in petroleum exploitation and crude oil pollution treatment.