Washington State University researchers develop a way to grow algae more efficiently -- in days instead of weeks -- and make the algae more viable for several industries, including biofuels. Their work is reported in the journal Algal Research.
Researchers would like to produce algae efficiently because of its potential environmental benefits. Oil from the algae can be used as a petroleum alternative and algae also can be used as food, feed, fiber, fertilizer, pigments and pharmaceuticals. Growing and harvesting it in wastewater streams could also reduce the environmental footprint of many manufacturing processes, according to the university.
It’s use in industry reportedly hasn't caught on primarily because it requires a lot of time and water to grow. Generally, large ponds are required, and harvesting is labor intensive. Researchers have begun developing biofilm reactors to grow the algae, but the reactors aren't efficient because of pH or temperature variations or a limited supply of carbon dioxide gas.
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 biofilm reactor that recycles gasses and uses less water and lower light than typical reactors, according to WSU.
The algae 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 reportedly 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, says 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 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.
For more information, visit: www.wsu.edu