Abstract: “Vegetable oils are of interest as a bio-based feedstock in the production of environmentally friendly alternative fuel. Microemulsification is an emerging technology to formulate mixtures of thermodynamically stable, isotropic liquid fuels, containing two or more immiscible phases stabilized by surfactant. In this study, three components including oil (vegetable oil/diesel blends), ethanol, and surfactant were conducted to formulate bio-based microemulsion fuels. The mixture of oils contain vegetable oil (palm oil or used palm oil or soybean oil) blended with regular diesel or biodiesel at a ratio of 50:50% (v/v), representing the non-polar phase. Ethanol facilitates the viscosity reducer, which is used as the polar phase. Mixed nonionic alcohol ethoxylate surfactant (C12-14-(EO)1-OH) and cosurfactants (octanol and ethylene glycol butyl ether) at a 1:8 molar ratio were selected to formulate reverse micelle microemulsion. The effects of vegetable oil types and cosurfactant structures on”

Keywords: Biofuel, Microemulsion fuel, Vegetable oil, Nonionic surfactant, Ternary phase diagram