Propane-Fueled Biodigester Wins EPA Award

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Washington, D.C. (April 25, 2007) – The ninth annual Environmental Protection Agency (EPA) Region 9 Environmental Awards recently recognized Dr. Ruihong Zhang and the Biogas Energy Project for developing an innovative waste-to-energy technology that is fueled by propane. The Biogas Energy Project is a joint endeavor by the University of California Davis (UC Davis), Onsite Power Systems, Inc., the Propane Education & Research Council (PERC), and other industry partners. The EPA Region 9 awards program acknowledges individuals and organizations in the Pacific Southwest that have made a significant commitment and effort to protect and improve the environment.

Dr. Zhang conceived the “anaerobic phased solids digester” for the Biogas Energy Project after eight years of university lab tests by her and students in the biological and agricultural engineering department of UC Davis. The anaerobic digester uses bacteria to break down and convert animal waste, plant waste, and food waste into biogas, a form of methane. It converts up to eight tons of food and yard waste per day, producing enough energy to power approximately 80 homes while reducing solid waste in landfills and greenhouse gas emissions that contribute to global warming.

“Dr. Zhang’s anaerobic digester is an innovative solution to the problems of waste buildup and pollution, and PERC congratulates her on a well-deserved award,” said PERC Director of Agriculture Programs Mark Leitman. “PERC is honored to be part of the development of this groundbreaking technology.  We are encouraged by Dr. Zhang’s advancements in waste to energy systems and proud that it is supported by clean, reliable propane.”

Propane serves as supplemental power for start-up, shutdown, and temperature control for the anaerobic digester to ensure stable, uninterrupted operation. To meet this need, PERC funded the purchase of two propane-fueled boilers; a low-emission, California Air Resources Board-certified propane engine; and a generator for the project.

The Biogas Energy project's digester uses the propane-fueled boilers to maintain internal heat at the temperature required to promote optimal bacteria growth to produce the most efficient natural breakdown of wastes. Propane can also serve as a reliable backup energy source for other digester operations when it cannot run off its own energy production.

“We made propane the sole fuel source for starting up and shutting down the system," said Dave Konwinski, CEO of Onsite Power Systems, Inc. "We installed a propane system because of its portability and ease of use in remote locations, making it a great fuel source for our anaerobic digester. And its environmentally friendly nature fits our goal of protecting our environment."

PERC's vision in agriculture is that by 2010, the agricultural industry will recognize propane as a preferred energy source offering exceptional value. This value is achieved through a unique combination of product benefits, including cost-effectiveness, efficiency and productivity, reliability, portability, and environmental friendliness.

For more information on PERC and its programs to promote the safe and efficient use of propane
in agriculture, call (202) 452-8975 or visit