Biosurfactant surfactin with pH-regulated emulsification activity for efficient oil separation when used as emulsifier. (October 2017)

• Record Type: Journal Article
• Authors: Long, Xuwei; He, Ni; He, Yukun; Jiang, Jingjing; Wu, Tingyu
• Is Part Of: Bioresource technology. Volume 241(2017)
• Page Start: 200
• Page End: 206
• Publication Date: 2017-10
• Subjects: pH-Regulated -- Biosurfactant -- Surfactin -- EOR; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2017.05.120
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Surfactin has a pH-regulated emulsification activity. Surfactin precipitated and lost emulsification activity under acidic pH. Surfactin can be readily reused after oil separation. Surfactin has great application feasibility in EOR. Abstract: In the present study, the pH-regulated emulsification activity of surfactin was studied and its potential application in oil separation towards enhanced oil recovery (EOR) was investigated. As demonstrated, surfactin can stabilize emulsions quite well beyond pH 7.4. An oil emulsification ratio of about 98% was obtained at pH 11.0; while this emulsification activity was rapidly and completely lost when pH decreased to below 3.0, having an oil separation ratio of over 98%. This pH-sensitive property is probably due to surfactin dissolution-precipitation induced by the ionization-protonation of a carboxyl group in its structure under alkaline or acidic conditions. This property allows oil emulsification or oil separation to be readily achieved via simple pH adjustments when surfactin is used as an emulsifier. Furthermore, surfactin sustained its activity after demulsification and can be readily reused many times. The above obtained results indicated surfactin-based EOR processes have great application feasibility.