Stability of W/O Emulsions Made from Aqueous Alcohol Solutions and Fuel Oil

The effect of alcohols in water phase on the breakage time of oil-in-water emulsions made from diesel fuel and fuel oil (A) was experimentally investigated. The presence of monohydric alcohols such as methanol and ethanol destabilizes water-in-fuel emulsions prepared using Span 80, although these emulsions have much longer breakage time than water-in-kerosene emulsions. The surface excess of the surfactant (Span 80) at the fuel/aqueous ethanol solution interface was measured. The presence of ethanol reduces the surface excess for the two fuel/water systems, as likely as the kerosene/water system. Such behavior of the surface excess corresponds to the reduction of the breakage time by the alcohols.