Corn Ethanol Production

Ethanol is one of the most popular types of biofuel. In the U.S. most biofuel is made of corn, thanks to official subsidies as well as blend mandates, even though corn biofuel production attracts controversy for its dubious environmental and ethical records.

The dry-grind process is the most common milling method used in corn ethanol production. In this case, the whole corn kernel is ground and turned into ethanol. It is considered more cost effective than wet-milling, which separates the fiber, germ and protein from the starch before being fermented into ethanol.

A study on corn ethanol production carried out by researchers at University of Nebraska-Lincoln found that corn ethanol directly emits 51 per cent less greenhouse gas per gallon produced than gasoline. The researchers concluded that improvement in the corn ethanol production process accounted for the difference. New, more efficient plants now represent about 75 percent of total corn ethanol production, researchers say. These newer biorefineries have increased energy efficiency and reduced emissions through the use of improved technologies.

On the downside, a report published the Environmental Science and Technology journal revealed that corn ethanol production uses a lot more water than previously thought. Depending on regional irrigation needs, the amount of water used for corn ethanol production ranges from 5 to a 2,138 liters of water per liter of ethanol. In places like Ohio, Iowa and Kentucky, corn can grow with little to no irrigation whereas in Nebraska, Colorado and California corn crops require a huge amount of irrigation.

Besides the water issue, corn ethanol production has also been criticized for its use of pesticides, soil erosion and competition for agricultural land with food crops, to name but a few.