Due to the steady depletion of fossil energy sources and associated environmental damage, transport companies and individuals are looking for alternative fuels. One of such alternatives is ethanol, which has been utilized diversely for thousands of years. Currently, ethanol is one of the most promising biofuels that are likely to substitute the traditional energy sources. Recent trends show a significant ethanol production and consumption growth, along with biodiesel and some other renewables. According to Gupta and Demirbas (2010), ethanol fuels production doubles every four years: “The global ethanol production has increased from 10.7 billion gallons in 2004 to 20.4 billion gallons in 2008” (p. 75). This paper covers pros and cons of the ethanol fuel, as well as relevant government’s policies that regulate its use.
Combustive properties of ethanol differ significantly from those of traditional fuels: “When compared with gasoline, ethanol has a higher octane number, broader flammability limits, higher flame speeds, and higher heats of vaporization” (Gupta & Demirbas, 2010, p. 73). These characteristics are essential in the use of ethanol as a transportation fuel. High octane number allows for the compression increase in the internal combustion engines, resulting in a higher performance. Safety considerations also favor the use of high-octane fuels, as the probability of uncontrolled ignition (detonation) is low due to the required high compression level. Additionally, the high octane number makes ethanol fuel suitable for both atmospheric and turbocharged engines.
High flame speeds of ethanol result in a very short burn time in comparison with traditional fuels. This feature allows constructing engines with higher rotational velocity, which in turn leads to the performance increase. High rotational velocity also facilitates the mechanical power transmission through the multi-level gears, increasing the engine efficiency. Ethanol contains 35 percent of the oxygen, which makes it a highly oxygenated fuel in contrast with fossil fuels. Consequently, the combustion process does not require as much additional oxygen as in the case with traditional fuels. On top of this environment-friendly feature, ethanol combustion produces extremely small amount of harmful particles and nitrogen oxides.
There are certain disadvantages, associated with the ethanol use as a transportation fuel. Ethanol can be easily mixed with the water, which will reduce its usability dramatically. Low vapor pressure makes the cold engine start problematic, limiting the ethanol use in the traditionally cold regions. Although the ethanol toxicity is much lower in comparison with fossil fuels, massive spills can cause certain environmental damage as well.
Generally, government regulations tend to promote the ethanol production and consumption as a transportation fuel. In early days of this new application of ethanol, state and local authorities were rather cautious: “Their concern relates … to the potential for evasion and abuse of the … tax structure that exists for the manufacture of distilled spirits for human consumption” (Freudenberger, 2009, p. 27). However, the advantages of the new approach soon became apparent, and now it is enough to obtain an Alcohol Fuel Producer Permit to start the ethanol production. According to Freudenberger (2009), “Today, any questions tend to be more related to environmental issues, fire and safety codes, and insurance liability” (p. 37). Close governmental control does not prevent the rapid growth of ethanol fuel industry as long as producers abide by the state laws.
Current trends demonstrate that the share of traditional fuels in transportations will continue to decrease. Growing complexity of the fossil fuels extraction, subsequent prices rise and the environmental damage will encourage the use of alternative energy sources, especially the renewable ones. Ethanol fuel is likely to play one of the major roles in the approaching fuel markets’ restructuring.