Optimization of vegetable oil detachment from oilseed by minimizing interfacial tension

Abstract

N-hexane has been widely used in vegetable oil extraction industry since it yields high extraction efficiency. However, n-hexane is categorized as a hazardous pollutant due to safety, health, and environmental concerns. Thus an alternative approach for oil extraction method that is free from n-hexane would be worthwhile to develop. In this work, mixed commercial anionic and nonionic surfactants in brine solution were purposed to be used for oil extraction. The results showed a good potential to use as extraction medium in aqueous surfactant-assisted extraction method (ASE). The oil detachment efficiency was exceed 70% for both jatropha and canola oil extraction. In case of canola, the ASE conditions were further modified for maximizing the oil yield. The surfactant concentration, stirring and ultrasonication time, and oilseed to extraction medium ratio significantly impacted the oil detachment and oil extraction efficiency. The effect of extraction temperature was not statistically significant. The triple extraction with three-states reduced the use of extraction medium. The highest oil detachment and oil extraction efficiency were 80% and 60%, respectively. In addition the canola oil from ASE method was found to have a superior oil quality to that of Soxhlet extraction in term of lower acid value and phospholipids content which are the important parameters for the quality of biodiesel feedstock.