Web exclusive posted Dec. 3, 2008 at 11:25 a.m. CST

Researchers at the Center for Renewable and Alternative Fuel Technologies at Eastern Kentucky University in Richmond, Ky., are partnering with San Diego-based General Atomics to study the potential for converting cellulosic biomass into biodiesel and ultimately jet fuel.

General Atomics is best known for its affiliated company, General Atomics Aeronautical Systems Inc., the manufacturer of the U.S. military's Predator unmanned aircraft system.

According to Dr. Bruce Pratt, chairman of the Department of Agriculture at EKU, researchers will look at using commercially available cellulase enzymes to convert cellulosic biomass to sugars, which will then be fed to heterotrophic algae that can convert sugars to oils without photosynthesis. "These are not the phototrophic types (of algae) that use sunlight," Pratt said. "These are membranous-type algae and they are heterotrophic, because we need to feed them the nutrients rather than getting the nutrients from the sun. These strains of algae have very high oil content." The oils are then extracted from the algae and converted to biodiesel.

Pratt said the process is similar to how cellulosic ethanol is produced, but the end product is biodiesel. "The similarity is that we're using biomass and we're going to be digesting it to release the sugars," he said. "To get ethanol, you take those sugars and ferment them to make alcohol. Our difference is taking the sugars and feeding them to algae and having the algae produce the oils."

The researchers are choosing to produce biodiesel instead of ethanol because biodiesel is a key fuel for heavy industry, Pratt said. "With biodiesel, you have a product that is going to have more industrial applications," he added. "Diesel runs industry: our trucks on the road, our trains, our freighters out on the ocean, our jets – jet fuel is not too far from diesel fuel – whereas ethanol is primarily just a gas additive for the auto industry. Both of them are very important and have a place."

EKU scientists will analyze multiple non-food feedstocks for the program – including corn stover, woody biomass, switchgrass, and sorghum – to determine potential crop yields and the best feedstock for the conversion process. EKU will also identify which land in Kentucky might be cultivated for energy crop production without negatively impacting existing agricultural businesses. One of the project's goals is to provide Kentucky's tobacco farmers with cash crop alternatives, according to Doug Whitlock, president of the university. Pratt said tobacco stalks, a crop residue, might also be considered as a feedstock.

EKU will also examine the logistics for transporting feedstocks to regional processing facilities and determine the economic impact of energy crop production in the region. The researchers will also examine uses for byproducts.

As a partner, General Atomics will provide input on the cost of converting various feedstocks to biodiesel and will design the processing system that will be used to derive biodiesel from cellulosic biomass.

According to the university, the project is being funded through a $4 million federal appropriation contained in the Consolidated Security, Disaster Assistance, and Continuing Appropriations Act of 2009.