Feasibility of stabilizing water-methanol-gasoline mixtures by emulsification

Abstract Co-solvents are used in methanol-gasoline blends to minimize the phase separation problem caused by contact with water. As an alternative, we evaluated the feasibility of emulsifying water and methanol in gasoline. The study included determination of the phase equilibrium composition for water, methanol, and a surrogate gasoline (30 wt% toluene and 70 wt% isooctane) and measurement of interfacial tensions between the equilibrium phases at 20 °C. Results showed that ethoxylated fatty acid emulsifiers formed stable emulsions, but at concentrations greater than 1 wt%. Microcrystalline particles failed to form emulsions or to enhance emulsion stability.