Mechanical Engineering Ph.D. student finds microalgal-biofuel has a lower water footprint than conventional biofuels

Casual outdoor portrait of researcher David Quiroz
David Quiroz is a mechanical engineering Ph.D. student working in the Sustainability Research Laboratory.

Algae takes less water than other alternative materials used to make sustainable biofuels, according to new research by David Quiroz, a fourth year Ph.D. student in the Department of Mechanical Engineering, published in the journal Environmental Science & Technology.

Quiroz conducts his research out of the Sustainability Research Laboratory with lab director and mechanical engineering Associate Professor Jason Quinn. Quinn uses computer modeling to determine whether emerging technologies are truly sustainable – meaning they are economically viable and reduce environmental impacts compared to the “business as usual” alternative.

Quinn’s recent research has focused on algae’s usefulness as a biofuel source. Algae has become a hot topic in sustainability not only because it can be used as a fuel source, but it can pull carbon from the air and filter out harmful algae in bodies of water. One major concern of algal-sourced biofuel is the amount of water it requires to produce.

“In the past we’ve constructed models looking into algae farms and biorefineries, but one thing that was missing from those models was accurate water accounting for the whole process of producing biofuel from algae,” Quiroz said. “We felt well equipped to tackle this specific question, not only with our modeling capabilities but also being located in Colorado where we really see the impacts of drought.”

Quiroz’s model quantifies the water stress of microalgal-biofuels across the United States compared with other biofuels, such as corn ethanol or soybean diesel.

“Water stress is extremely important to consider because consuming one liter of water in Tampa, Florida is not the same as consuming a liter of water in Phoenix, Arizona. The scarcity of water varies across the country,” he said.

The study concludes that the “water footprint,” or the amount of water it takes to produce microalgal-biofuel from start to finish, is smaller than the water footprint of alternative biofuels.

Quiroz plans to explore the relationship between algae and water further by focusing on water in the West and how algae can reduce water scarcity through more efficient biofuel production.

“I’m excited,” he said. “This work is impactful, not only for the algae community, but also in terms of biofuels. Algae has the potential to not only lower carbon emissions but lower water consumption, too.”