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Biodiesel explained

By Staff | Oct 28, 2008

Biodiesel, how it is made, how it is marketed and how it is used were the topics of a presentation by Alicia Clancy of Renewable Energy Group of Ames. Clancy spoke at the annual Ag for Reporters seminar last Thursday in Newton.

Started in Ames in 1996, REG now markets 20 percent of all biodiesel in the U.S. The company both owns and manages or has in planning biodiesel plants in Iowa, Texas, Illinois, Louisiana, Kansas, California and Edmonton, Alberta.

Biodiesel is made from soybean oil and other oils and uses a transesterfication process which used methanol as a catalyst. When it goes into a diesel engine, biodiesel actually acts as a solvent and cleans out the fuel system, increasing engine life. Biodiesel, which is sulphur-free, reduces overall emissions from diesel engines.

While some people may argue about the energy inefficiency of producing biodiesel, Clancy said biodiesel returns 3.5 energy units for every unit used in its manufacture. Petroleum diesel, by contrast, has a net energy loss in its manufacture.

In addition to use in blending with regular diesel, biodiesel has applications in underground mines. Over-the-road trucks use about two-thirds of all diesel in the U.S., making it the primary market for biodiesel.

Biodiesel blends vary according to application. A 5 percent biodiesel/diesel blend, or B-5, can be used in designated Volkswagen diesel engines while B-20 is used in Cummins, Case IH, Daimler/Chrysler/Jeep and John Deere engines. Some Case models can use B-100, said Clancy.

Oils other than soy oil that can be used in biodiesel manufacture include corn oil, canola oil, camelina oil, recycled kitchen grease, algae and even the moringa tree, an application in India.

The group later toured the Central Iowa Energy-managed biodiesel plant near Newton. General manager Derek Winkel said the plant produces 500,000 gallons of biodiesel every six days. The plant has a yearly overall annual production capacity of 30 million gallons.