Direct Injection Ethanol Boosted Gasoline Engines: Biofuel Leveraging For Cost Effective Reduction of Oil Dependence and CO2 Emissions

Direct Injection Ethanol Boosted Gasoline Engines: Biofuel Leveraging For Cost Effective Reduction of Oil Dependence and CO2 Emissions:
by D.R. Cohn, L. Bromberg, J.B. Heywood -- MIT
"This ethanol boosted engine concept uses a small amount ethanol to increase the efficiency of use of a much larger amount of gasoline by approximately 30%. Gasoline consumption and the corresponding CO2 emissions would thereby be reduced by approximately 25%. In combination with the additional reduction that results from the substitution of ethanol for gasoline as a fuel, the overall reduction in gasoline consumption and CO2 emissions is greater than 30%. The concept uses appropriately controlled direct injection of ethanol into the engine cylinders. The direct injection provides suppression of engine knock at high pressure. This allows high pressure operation of a much smaller, highly turbocharged engine with the same performance as a larger engine. The engine can also use a higher compression ratio. "