Preparation of surfactants for enhanced oil recovery from alkali lignin pretreated with hydrogen peroxide.

The method for synthesis of surfactants for enhanced oil recovery,including pretreatment with H2O2,sulfonation, amination and alkylation,was studied with alkali lignin as feedstock. Firstly,the effects of pretreatment conditions on surface tension were investigated. The suitable pretreatment conditions were that mass ratio of H2O2to alkali lignin was 1 ∶ 10 at 70 ℃ for 30 min. Under the pretreatment conditions,the surface tension of 0. 9 % surfactant solution could be reduced to 24 mN / m. The effects of surfactant and alkali concentration on oil-water interfacial tension of Gudao crude oil were also studied. The results showed that when both the surfactant concentration and NaOH concentration was 0. 4 %,the oil-water interfacial tension was decreased to 0. 07 mN / m. It was more stable than the control surfactants synthesized without H2O2pretreatment. Finally,Fourier Transform Infrared( FT-IR) analysis indicated the structural characterization of lignin before and after modification.