Combustion and Emission Characteristics of Gasoline Blended with Alcohols

Methanol and ethanol are known as potential alcohol alternative fuels for spark ignition Engines, which can be blended with gasoline to increase oxygen content and to decrease emissions. Six kinds of fuels were prepared, they are commercial 93#gasoline, M10, M20, M30, E10 and E20. With a constant volume bomb, flame propagation speeds were studied under different temperatures, exhaust dilution and air fuel ratios. The flame radiuses were used to calculate the flame speed. The results indicate that methanol can increase flame speed no matter with or without exhaust dilution. At the ambient temperature of 5 ℃ and 15℃, engine cold start tests prove that methanol can improve engine combustion and lower HC and CO emissions during the first 200 seconds, while ethanol has little effects at the same conditions