The Pros & Cons of Ethanol Biofuel

Ethanol biofuel is manufactured from living organisms and biological substances such as plants, algae and manure. Though corn is the best known source of ethanol, other important sources include soybeans, switchgrass and farm wastes. Ethanol is a small alcohol molecule that burns cleanly. Debate continues about the relative importance of its pros and cons as a biofuel.

Despite being a net exporter of crude oil, the United States imported 1.65 billion barrels of oil during the first seven months of 2013, of which 757 million barrels came from the members of the Organization of Petroleum Exporting Countries. Ethanol can be manufactured using domestically grown crops, allowing the United States to reduce its dependence on foreign oil. Consumers can benefit because domestic ethanol buffers against foreign petroleum price spikes. The military benefits because it has access to a secure source of energy that isn’t subject to international political pressures.

Ethanol burns more cleanly than does gasoline and creates fewer greenhouse emissions. A study by the Argonne National Laboratory shows that ethanol from corn has 20 percent lower emissions, while cellulosic ethanol, from sources such as prairie grasses and farm wastes, reduces emissions by 85 percent compared to gasoline. An E85 blend of 85 percent cellulosic ethanol and 15 percent gasoline cuts greenhouse gases by 64 percent. Ethanol added to gasoline also reduces the output of carbon monoxide, nitrogen oxide, sulfates and particulate matter.

Ethanol has a lower energy content than does gasoline and diesel fuel. Gallon for gallon, ethanol in your vehicle's fuel tank will produce fewer miles, less power and faster consumption. It’s difficult to find E85 fuel in the United States, but if you could buy it, you’d see your vehicle's mileage drop by 25 percent to 30 percent. Gasoline containing 15 percent ethanol -- known as E15 -- isn’t approved for cars built before 2001 because of damage it might do to rubber seals. Some automakers advise against the use of E15 fuel. So do some makers of gasoline-powered chainsaws, lawn mowers and watercraft.

Corn channeled into ethanol production is not available as food for humans and livestock. In 2012, ethanol production required 30 percent of the U.S. corn crop, after accounting for byproducts of ethanol production, such as corn oil. The World Bank lists biofuels such as ethanol as one of the causes of a 104.5 percent increase in food prices in the years from 2000 and 2012. Land and water diverted to ethanol-producing crops impacts the availability and price of food. For poor nations, this tension might lead to a terrible dilemma: whether scarce resources should be allocated toward ethanol crops or food.