According to the estimation from Council of Agriculture, Executive Yuan, sweet potato is the most feasible feedstock in Taiwan. Based on the forecasting by this project, 30 thousand myrialiters fuel ethanol are produced from the sweet potatoes production by using 60 thousand hectares fallows. In addition, the capacity of agricultural residuals is around 21.9 hundred thousand tones. They will be produced the cellulosic ethanol about 72 thousand myrialiters. Through the summary of other countries’ researches, it is statement that the air pollution will be improved by using E10 and CO2 emission will be decreased 17.2 tones / myrialiter based on the environmental life cycle assessment. To consider the feasible of cars with adding ethanol, the first development phase is promoting 3% ethanol. The potential ethanol demand is 28 thousand myrialiters. When the aim is promoting E10, the ethanol demand is 103 thousand myrialiters. In the future, the short-term competition of fuels is ethanol fuel but the long-term competition is the hydrant engine and hydrant/ fuel cell. In this project, for emission test, there are 5 cars with 10 times with E3. The result states that the new cars have less effect for emission test but used cars with the emission of HC, NMHC and CO are increased obviously but CO2. We suggest holding the large scale emission test to more vehicles by using E3 or more than E3. When using E3 can not have the positive effect to prevent from air pollution, then we won’t suggest promoting fuel ethanol or without using subsidy of the air pollution fund. On the contrary, when the result is positive effect, government imposes energy tax and the fuel ethanol price is competition, air pollution fund will be not used, too. However, when the government does not impose energy tax and the fuel ethanol price is also not competition, air pollution fund is suggested to be used for subsidy. For the optima plan with promoting fuel ethanol, based on the objectives of using ethanol include diversifying energy supply, increasing rural economy, building the biomass industry, lowering the carbonic emission, we propose three important phases for ethanol development. Phase I is demonstration from year 2007 to year 2010. Phase II is supplying E3 fully in 2013 and the aim of supply is 10 thousand myrialiterss of ethanol. Domestic producers can produce the 30 thousand myrialiterss of ethanol in 2015. Phase III is promoting E10 and cars will be added coercively in 2025 For the instance of cost -effective evaluation, when producing the 30 thousand myrialiterss of ethanol, the accumulative cost will be NTD 193 millions from year 2007 to year 2015 and accumulative effective will be NTD 400 million.

Fuel Ethanol , How feasible for vehicles, cost-effective evaluation