STEP@USF

In most countries alternative fuels, such as ethanol, are actually a mixture of ethanol and gasoline. These ethanol fuel mixtures have “E” numbers which describe the percentage of ethanol in the mixture by volume. For example, in the US many ethanol fuel mixtures are designated E10, which means 10% of the fuel is composed of Ethanol and the remaining 90% is composed of gasoline. Determine how efficient, in terms of gallons of gasoline consumed per mile, E10 is when compared to gasoline. As the ratio of ethanol to gasoline in an ethanol fuel mixture is increased determine how the efficiency of the fuel changes.

Theory:

• Derivative as an instantaneous rate of change (Neuhauser, Claudia. Calculus for Biology and Medicine. New Jersey: Prentice Hall, 2000. 95)

References:

• Shapouri, H., J.A. Duffield, and M. Wang. 2002. The energy balance of corn ethanol: an update. USDA Agricultural Economic Report Number 814.
• Pimentel, D. 2003. Ethanol Fuels: Energy Balance, Economics, and Environmental Impacts are Negative. Natural Resources Research. 12(2): 127-134.
• De-gang, L., H. Zhen, L. Xingcai, Z. Wu-gao, and Y. Jian-guang. 2005. Physico-chemical properties of ethanol–diesel blend fuel and its effect on performance and emissions of diesel engines. Renewable Energy. 30: 967–976.
• Niven, R.K. 2005. Ethanol in gasoline: environmental impacts and sustainability review article. Renewable and Sustainable Energy Reviews. 9: 535–555.