Abstract
This work reports the synthesis and application of amphiphilic ionic liquid (IL) in the petroleum field. The ionic liquid was synthesized by etherification of octadecylamine with tetraethylene glycol followed by quaternization with p-toluene sulfonic acid. The chemical structure was confirmed by NMR spectroscopy. The surface activity, aggregation, adsorption, and the solubility of the ethoxylated octadecylammonium tosylate were investigated. The interfacial parameters between IL aqueous solution and crude oil emulsions were determined from interfacial tension measurement. The results showed the dependence of interfacial tension on the concentration, crude oil emulsion composition and chemical structure of the prepared amphiphiles. The mechanism of aggregation and adsorption ethoxylated octadecylammonium tosylate was proposed and confirmed at different interfaces. The demulsification and oil spill dispersion efficiencies were investigated at different amphiphile concentrations. The performance of amphiphilic ILs revealed that their demulsification efficiency reached 100% and the settling time required for efficient separation decreased with increment of water contents of crude oil emulsions. Moreover, the prepared amphiphilic ILs achieved oil spill dispersion efficiency more than 80% at surfactant oil ratio (1:25).