Using the GREET model to analyze algae as a feedstock for biodiesel production

There is a growing interest in renewable, carbon-neutral biofuels such as ethanol and biodiesel. A life-cycle analysis is conducted in this study to determine the viability of using algae as a feedstock for biodiesel. The method involves assessing energy use, fossil fuel use, greenhouse gas emissions, and criteria pollutant emissions using a simulation developed by Argonne National Laboratory. The energy and emissions of algae-derived biodiesel are compared to those of soybean biodiesel, corn ethanol, conventional gasoline, and low-sulfur diesel. Results show that there are sizeable greenhouse gas emission benefits attributed to the production of both types of biodiesel as compared to petroleum fuels. Energy expenditures are much larger when producing algae biodiesel than compared to the other four fuels. The alternative scenario of growing algae at a wastewater treatment plant is also evaluated and is proven to reduce fossil fuel consumption by 17%. The results suggest that producing biodiesel from algae, while not yet competitive regarding energy use, does have many benefits and is worthy of further research and development.