Technical Paper
Volatility Characteristics of Blends of Gasoline with Ethyl Tertiary-Butyl Ether (ETBE)
1990-05-01
901114
Ethyl tertiary-butyl ether (ETBE), a reaction product of ethanol and isobutylene, has been proposed as a high-octane blending component for gasoline. Laboratory studies have been conducted to determine how the addition of ETBE to gasoline affects the volatility characteristics of the fuel, and how the effects of ETBE compare with those of the commonly used oxygenates, ethanol and MTBE. The amount of vapor generated in bench-scale simulated evaporative emissions tests with each of those three oxygenates was also determined. The vapor pressures of gasoline-ETBE blends decreased linearly as the concentration of ETBE was increased. In contrast, ethanol addition raises the vapor pressure of gasoline, although in a nonlinear fashion. ETBE increased the mid-range volatility of the fuel, in the same way as a pure hydrocarbon of similar vapor pressure and boiling point.