Ethanol-Gasoline Mixing and Vaporization Thermodynamics: The Influence of the Hydrocarbon Type and Content

One of the most important thermodynamic properties of ethanol–gasoline system – enthalpy of vaporization – was studied. Values of partial molar enthalpy of vaporization were reported for the first time. They were found to be constant. These values can help normalize alcohol–gasoline blended fuel volatility and make this fuel more competitive than ordinary gasoline. The dispersed structure of ethanol–gasoline mixture was shown. The most important parameter of any colloid structure, i.e., the radius of the dispersed particles, was reported. Its value was hundreds of nanometres and it dramatically depends on the concentration of ethanol. These data can help prevent phase-separation in ethanol–gasoline fuel caused mainly by the coalescence of alcohol–water drops and precipitation. Changing the colloid structure of ethanol–gasoline systems can be an effective way to put in order the quality coefficients of the fuel. The influence of the hydrocarbon type (normal or branched alkanes, aromatics – BTX, naphthenes, etc.) and content on vaporization thermodynamics of ethanol-gasoline biofuel was discussed. General trends were found; they can be used to minimize the vapor pressure of ethanol-gasoline mixture.