A USDA chemist checks the color and quality of a corn fiber oil sample.
Keith Weller/USDA
In the world of ethanol, corn is king. Turning sugar-rich corn into ethanol is much like brewing beer. Workers first grind the golden kernels and mix them with warm water, and next add yeast. The yeast causes the slurry to ferment, or turn into energy-producing alcohol. Refineries blend ethanol with gasoline for use in existing car engines. Ethanol, whether it is made from corn, wheat or sugarcane, releases less carbon monoxide, nitrogen oxide and sulfur into the atmosphere than gasoline. Ethanol also reduces smog, which can minimize health problems for people, especially those living in cities.
Using corn kernels in the fermentation process is cheaper than using the entire corn plant. The sugar in the stalks and leaves of corn plants play hide and seek in a substance known as cellulose. Cellulose is difficult and expensive to break down. However, researchers are trying to make that process more cost effective. In addition, scientists at Michigan State University have developed a strain of corn that contains special enzymes that turn the stubborn cellulose into sugar, which engineers can ferment into ethanol. Scientists at Michigan State say their new strain of corn, Spartan Corn, will make the production of ethanol from plant waste cheaper and less time consuming [source: Science Daily].
No So Green?
Growing and processing corn into a biofuel actually uses a huge amount of fossil fuel. Once the refineries complete the distillation process, only about 20 percent of each gallon of corn ethanol is "new" energy [source: Tillman and Hill].
