Ethanol as an alternative motor vehicle fuel is not a new concept. In fact, before gasoline became so readily available, early automobile makers such as Henry Ford had suspected that ethanol would be the world's main fuel. Furthermore, many researchers agree that ethanol could substantially offset the worldwide use of traditional petroleum fuels.

In the United States, the use of ethanol is widespread, utilizing approximately one billion gallons each year. According to the United States Department of Energy, approximately 95% of U.S. gasoline contains a low-level blend of ethanol known as gasohol.

Production of ethanol from corn is limited by competition for farm land, as well as competition with markets for its co-products, such as distiller’s dry grain. The production of ethanol from corn is limited to around 16 billion gallons thus; the United States needs to derive new sources of ethanol to satisfy their demand. At present, the United States is considering importing ethanol from Brazil, as well as exploring the use of cellulosic ethanol. It has been argued that although ethanol derived from corn can reduce the United States use of petroleum, it only marginally reduces their greenhouse gas emissions. In contrast, the use of both cellulosic ethanol and sugarcane ethanol could result in the reduction of the United States’ petroleum dependence, as well as have significant impacts on their carbon dioxide emissions.

What is Ethanol?

Ethanol (CH3CH2OH) or grain alcohol, is a clear, colorless liquid. It is the same alcohol found in alcoholic beverages and it also functions as an excellent renewable fuel, when made from plant biomass.

The Ethanol Fuel Market

Ethanol as an alternative motor vehicle fuel is available in two forms.The first form is near 100 percent ethanol or E100 and the second form is a mixture with up to 15 percent gasoline or E85. To promote and encourage the use of ethanol as an alternative fuel, the United States government has subsidized ethanol use by partly exempting gasohol from gasoline taxes.

Advantages of Ethanol as an Alternative Fuel

There are many reasons why ethanol fuel is more HSE-friendly including:

  • It is a familiar liquid form

  • E85 reduces carbon dioxide emissions

  • E100 reduces the reactivity of organic emissions

  • Organic emissions such as ozone precursors would have a lower reactivity than gasoline, but higher than that of methanol

  • Lower emissions of toxic pollutants

  • Greater engine efficiency

  • It can be produced from domestic sources

  • The presence of alcohol causes the engine to run effectively lean since the air-fuel mixture would contain more oxygen atoms

  • The availability of oxygen facilitates the combustion of carbon monoxide into carbon dioxide

Disadvantages of Switching to Ethanol Fuel

As with any fuel source, there are downsides to using ethanol:

  • It is much more costly than gasoline

  • If produced from corn, supply would be limited

  • It covers a distance of less than one third of that of gasoline

  • It increases engine out emissions of nitrogen oxides

  • Engine cold starts problems are associated with E100; most gasoline’s carbon monoxide emissions are associated with cold starts therefore, cold starts associated with E100 can increase E100’s carbon monoxide emissions

  • E85 has a higher volatility than gasoline; this results in a net increase in VOCs emission, which then negatively impacts upon ozone levels

The Economics of Ethanol Compared to Gasoline

As mentioned above, producing ethanol is much more costly than producing traditional petroleum fuels. As such, many governments have given tax incentives to make ethanol more competitive in the transportation industry.

  • Ethanol Facts: Environment

    • Ethanol is considered to be one of the most effective tools in the fight against motor vehicle air pollution

    • According to the Renewable Fuels Association: Ethanol contains 35% oxygen and, since adding oxygen to fuel results in more complete fuel combustion, harmful tailpipe emissions are reduced

    • Ethanol displaces the use of BTEX toxins found in gasoline, which are carcinogenic

    • Ethanol is non-toxic, water soluble and quickly biodegradable

    • Ethanol is a renewable fuel produced from plants, thus its supply is essentially unlimited

  • Ethanol Facts: Health and Safety

    • While ethanol is a much cleaner fuel than pure gasoline, most health experts are concerned with the practice of mixing ethanol with gasoline, as in the case of E85

    • Studies have shown that ethanol mixed with gasoline releases other components, such as peroxyacetyl nitrate, formaldehyde, and acetaldehyde into the air

    • Ethanol mixtures have been found to cause eye, nose and skin irritations, as well as internal irritation of the respiratory system

    • Additionally, exposure to vapours released during the mixing process can cause depression, dizziness, nausea, sleepiness, vomiting, unconsciousness and even death

    • Therefore, when working with ethanol fuel in terms of manufacturing, as well as distribution and sales, the appropriate PPE must be worn. For information on selecting the right PPE, check out 6 Personal Protective Equipment (PPE) Guidelines Every Employee Should Know

The Verdict?

While there have been various social, economic, environmental and technical controversies with ethanol fuel production and use, such as the food vs fuel debate, carbon emissions levels, sustainable biofuel production and impacts on water resources; no one can dispute the fact that ethanol fuel is more HSE-friendly than traditional petroleum fuels.

Still not convinced? Well... Using ethanol in place of gasoline helps to reduce carbon dioxide emissions by an average of 34% compared to gasoline. 13.3 billion gallons of ethanol produced reduced greenhouse gas emissions from on-road vehicles by 38 million metric tons in 2013. That is equivalent to removing 8 million cars from the road! New technologies are increasing ethanol yields. Therefore, efficiencies are also being improved, allowing ethanol biorefineries to make better use of natural resources.