The Iowa Power Fund board agreed Wednesday to entered funding negotiations for the state's first algae-to-biodiesel project, offering the promise of a new feedstock for Iowa's renewable fuels industry.
A pilot plant proposed by Green Plains Renewable Energy would use three byproducts from the company's Shenandoah plant - waste water, waste carbon dioxide, and waste heat from dryers - as feedstock to grow algae. The algae would then be harvested and processed into biodiesel
Green Plains' partner in the project, Cambridge, Mass.-based GreenFuel Technologies, worked with Arizona Public Service Co. to develop a algae-based bioreactor that produces ethanol biodiesel from power plant gases and ethanol in Arlington, Ariz.
GreenFuel has also led other projects including development of an algae farm at the Sunflower Integrated Bioenergy Center in Holcomb, Kans., using emissions from a coal-burning power plant.
Connell said Iowa's temperate climate has advantages for algae-based systems because it requires less energy to heat water to the temperature needed by growing algae than to cool it in hot southern climates. Carbon dioxide emissions from natural gas-fueled ethanol plants are more suitable for growing algae than carbon dioxide emissions from coal-burning plants because the emissions contain fewer impurities, Connell added.
Harvested algae would be run through a centrifuge to remove water and then oils would be pressed from the algae, Connell said. The oils will be processed into biodiesel, and the remaining solids would be converted into animal feed that is a better source of protein for swine than the distillers dried grains produced by corn-based ethanol plants, Connell indicated.