Algae has the potential to become a sustainable raw material, but will be impractical until researchers can find a way to cut costs, according to a recent University of Minnesota analysis.
Research submitted last month by the University’s Department of Bioproducts and Biosystems Engineering found the main barrier preventing algae from being used in a variety of applications is its high price tag. Algae-produced items like biodiesel, pharmaceuticals and food sources were found to be energy efficient but expensive.
“What we concluded is algae in general is an expensive feedstock … economically, the cost of algae per ton is pretty high,” said research author Shri Ramaswamy, a professor within the department. “So as a result, in the past, people have thought of making biodiesel from algae, but it may not be feasible.”
Researchers say finding more applications for algae would spur a higher supply of the plants and would drive the creation of cheaper methods of producing them, making algae-based biodiesel more economically feasible.
“If you are really trying to get the cost to make algae-produced biodiesel down, then you need to add these other products potentially, because right now if you try to produce just the algae, it doesn't really compete with things like methane,” said Brett Barney, a University professor and biofuel researcher.
Barney said algae may be useful as a sustainable food source in future space travel endeavors. Additional applications range from pharmaceuticals to fish feed, and could potentially include replacing sugarcane as a sugar source.
“If you could sit there and potentially replace even some of those crops with sugar-producing algae, you could potentially create whole new food sources that you could produce much more sugar much faster,” Barney said. “You can grow algae in a lot of different places that you can't grow these crops in, and that's where it has a benefit.”
Wastewater treatment is another industry which can benefit from algae, Ramaswamy said.
Bo Hu, University professor and algae cultivation researcher, said combining biodiesel production with wastewater treatment may help lower costs.
“[By] having the microalgae ... grow in the wastewater, and by stimulating all the nutrients for the algae cell biomass, when we harvest the algae cell biomass for biodiesel production we actually remove the nutrient pollutants from the wastewater,” Hu said.
Ramaswamy said this is the first study to look at year-round algae production costs throughout four different locations: Minnesota, California, New Mexico and Arizona. The researchers found the climate of southern states more fitting for growing algae for biodiesel, while climates like that of Minnesota are better suited for using algae for other types of production.
Due to its single-celled nature, algae can grow much faster and more efficiently compared to other plants.
“For example, carbon emissions ... can be taken and fed to this reactor as a carbon source for algae to grow,” said Ramaswamy. “So that sounds very attractive, because you are reducing the ... air pollution as well as growing a biomass species.”