Vapor pressures of alcohol-gasoline blends

Abstract

Reid vapor pressures (RVPs) were determined for alcohol-gasoline blends containing 5-85% by volume of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, i-butanol (2-methyl-1-propanol), and t-butanol (2-methyl-2-propanol). The results are compared to literature data. Most alcohols form near-azeotropic mixtures with hydrocarbons in gasoline that affect the vapor pressure of the blend in a non-ideal manner. In addition, vapor pressures of dual-alcohol blends with gasoline containing a range of ethanol and 1-butanol volume percentages were determined. We demonstrate a simple method to prepare dual-alcohol-gasoline blends with RVPs indistinguishable from that of the base gasoline. It may be advantageous to use alcohols in addition to ethanol in the form of dual- or multi-alcohol blends as these become available in larger scale in the future. © 2010 American Chemical Society.