Esterification of Polyoxy-Based Surfactant Utilizing Azeotrope Technique for Chemical Flooding Application

Abstrak

The need of fossil fuel which tends to increase without the increasing of oil production has become the main factor for applying Enhanced Oil Recovery (EOR) methods in the mature oil field. Chemical injection using surfactant is one of EOR technologies that has been proved to be able to increase the oil recovery. In this study, surfactant was synthesized employing palm oil as a hydrophobic group and polyethylene-glycol as hydrophilic groups. The use of natural oil as the raw material is likely due to its abundance and environmentally friendly. Esterification of nonionic surfactant was performed by utilizing the azeotrope technique (EtOAc-H2O) between oleic acid and polyethylene glycol (PEG) 400. The Reaction was optimized by a various mole equivalent of oleic acid and PEG (1:1,1; 1:2,5; 1;3) as well as various time reaction. Product surfactant was characterized by thin-layer chromatography (TLC), acid value (AV), and ester value (ES) to determine the optimum condition and reaction conversion. The Molecular structure of surfactant was confirmed by 'H and 13C NMR as well as MS. Nonionic surfactant was then analyzed by measuring the interfacial tension (IFT) of oil and water. The results showed that the optimum condition to obtain the lowest IFT was achieved by reacting oleic acid and PEG at mole equivalent ratio of 1:3 and 5 hours reaction time, with conversion reaction of 93.7% mole. This nonionic surfactant was able to decrease the IFT of oil and water as low as 104 dyne/cm in brine salinity condition of 18000 ppm and oil 34,39°API.