Ethanol - the miracle fuel?

World demand for oil products seems to know no bounds. According to recently released data from the International Energy Agency (IEA), the world's demand for oil products grew to 83.6 million barrels per day in 2005, up from 79.3 million barrels per day in 2003! If present trends continue, the IEA estimates that by 2007, demand will be 86.4 million barrels per day.

Although the greatest growth in demand for oil products over the past few years has occurred in China, other regions of the world are also experiencing growth, including Asia (excluding China), the Middle East, and Africa. In fact, demand continues to rise in the United States, despite the price of gasoline being over three dollars a gallon.

On the supply side, the number of net exporting countries continues to decline, in part because of rising local demand, but also because of declining crude oil reserves. Production in countries such as Norway and the United Kingdom peaked around the turn of the century and is now in decline. As crude oil production falls in various countries, other countries must produce more to ensure that the growing demand continues to be met.

Since the transportation of goods and people is responsible for over half of the world's demand for oil production, it is necessary to have an ever increasing supply of gasoline and diesel fuel.

The production of gasoline is becoming an issue, especially in North America, as the supply of light and medium crudes (ideal for refining into gasoline) is in decline. This, coupled with the concern in the United States over security of oil supply, has prompted individuals, companies, and politicians to push for alternatives to gasoline.

Perhaps the most talked about of these alternatives is ethanol, an alcohol that can be mixed with gasoline; the resulting product can be used, with some technical restrictions, in place of gasoline. Most gasoline-powered vehicles in North America can run on gasohol or E10, a fuel consisting of 90 percent gasoline and 10 percent ethanol (the 'E' denotes ethanol and the number indicates the percentage of ethanol). The new flex-fuel engines are designed to operate on a range of ethanol mixtures, from gasoline with no ethanol added, to 85 percent ethanol, or E85.

The principal argument for ethanol made by politicians such as President Bush and Prime Minister Harper is that it reduces oil imports since ethanol can be produced from corn grown in North America. Other arguments for corn-derived ethanol include its lower carbon dioxide emissions and that it ensures farmers an income. Although there is validity in all of these arguments, ethanol should not be considered a miracle fuel.

The energy available in a litre of ethanol is about two-thirds that of a litre of gasoline; this means a litre of a gasoline-ethanol mixture has less available energy than does a litre of gasoline. In the case of E10, the difference is negligible, about three or four percent; however, E85 is a different matter altogether.

A litre of E85 has less than three-quarters the energy content of a litre of gasoline. This fact becomes apparent when the fuel economy of flex-fuel vehicles is determined using different fuel mixtures. The following table from the U.S. Department of Energy's 2006 Fuel Economy Guide highlights these differences (the fuel costs assumed 15,000 miles traveled per year and E85 and unleaded gasoline to cost $2.00 and $2.20 per gallon, respectively):

Annual fuel cost
(U.S. dollars)
Stratus 4-doorE851520$1,764

Ram 1500 PickupE85911$3,000

Yukon XL 4WDE851114$2,499


Since ethanol is a biofuel derived from corn, it is necessary to devote cropland to its production. According to the U.S. Department of Energy, a ton of dry corn produces about 124.4 gallons of ethanol (about 427 litres of ethanol per tonne). Corn crop yields vary by moisture, length of growing season, and soil fertility. In Canada, yields are between 5 and 10 tonnes per hectare, giving an ethanol production volume between 2,135 and 4,270 litres per hectare.

On one hand, this seems like a lot of ethanol, on the other, it seems like a considerable amount of cropland. For example, replacing Atlantic Canada's 3.12 billion litres of gasoline with E85 would require between 900,000 and 1.8 million hectares of cropland. Something not easily attainable, since presently Atlantic Canada has about 1 million hectares devoted to agriculture, about forty percent of which is used in the production of food.

Proponents of ethanol point to new technologies that will use the cellulose of the plant rather than the seed and the use of dedicated energy crops to produce ethanol. However, even these technologies will ultimately be limited by the availability of cropland.

It is not only the world's demand for oil products that seems to know no bounds; the world's population is also increasing. With more mouths to feed (and fuel tanks to fill), it is becoming apparent that using a less-efficient fuel derived from agricultural products is not sustainable.

It is clearly time to reconsider how we move goods and people.

Published: Atlantic Construction and Transportation Journal - August 2006