Washington State University researchers have developed a biofilm reactor to grow algae more efficiently, and make the algae more viable for several industries, including biofuels. Their work was reported in the journal Algal Research.

Led by graduate student Sandra Rincon and her advisor, Haluk Beyenal, professor in the Gene and Linda Voiland School of Chemical Engineering and Bioengineering, the researchers developed a unique biofilm reactor that recycles gasses and uses less water and lower light than typical reactors.

The algae they produced was full of the fats that make it suitable for biodiesel production and “fatter” than other biofilm reactors have produced. Because of a removable membrane, it was also easier to harvest than typical systems.

The system is unique because it allows the algae to simultaneously do photosynthesis like a plant while also “eating” carbon and respiring like an animal, said Dr. Beyenal.

The researchers fed the algae glycerol, a cheap waste product of biodiesel production, and urea, another inexpensive chemical that serves as a nitrogen source for the algae. The system’s design means that carbon dioxide and oxygen are recycled in the system.

“The cell, in fact, becomes a very efficient factory in which the nutrients are supplied by the medium, but the cell metabolism meets its carbon dioxide requirements internally,” said Ms. Rincon.

Like many new research efforts, the project was challenging, said Dr. Beyenal. He credits Ms. Rincon with her sustained efforts in spite of several setbacks that might have led others to quit and give up on the work. “The idea is new,” he said. “Sandra demonstrated that it worked at the lab scale.”

The researchers have filed a patent application on the technology and are working to optimize the process. Funded through a Fulbright fellowship, the research is in keeping with WSU’s Grand Challenges, a suite of research initiatives aimed at large societal issues. It is particularly relevant to the challenge of meeting energy needs while protecting the environment. 

—by Tina Hilding, Voiland College of Engineering