Analysis of Design of Pure Ethanol Engines

Ethanol, unlike petroleum, is a renewable resource that can be produced from agricultural feed stocks. Ethanol fuel is widely used by flex-fuel light vehicles in Brazil and as oxygenate to gasoline in the United States. Ethanol can be blended with gasoline in varying quantities up to pure ethanol (E100), and most modern gasoline engines well operate with mixtures of 10% ethanol (E10). E100 consumption in an engine is higher than for gasoline since the energy per unit volume of ethanol is lower than for gasoline. The higher octane number of ethanol may possibly allow increased power output and better fuel economy of pure ethanol engines vs. flexi-fuel engines. High compression ratio ethanol only vehicles possibly will have fuel efficiency equal to or greater than current gasoline engines. The paper explores the impact some advanced technologies, namely downsizing, turbo charging, liquid charge cooling, high pressure direct injection, variable valve actuation may have on performance and emission of a pure ethanol engine. Results of simulations are described in details providing guidelines for development of new dedicated engines.