Pond scum holds huge potential for capturing carbon dioxide and creating alternatives to petroleum-based fuels. But the nascent algae industry has to solve a three-part puzzle if it’s going to give oil a run for its money, according to Michael Weaver, co-founder and CEO of algae startup Bionavitas: Identify the (one) algae strains, (two) growing conditions and (three) extraction processes that yield large enough quantities of biofuels or other products at a cost competitive with oil extraction and refining.
One of the hurdles for high-yield, large-scale growth is a phenomenon called “self-shading.” Basically algae can’t grow beyond a certain density because it blocks out light — which algae needs for photosynthesis. We knew three-year-old Bionavitas was working on this natural limitation, and yesterday the company opened up about its technology. According to Weaver, Bionavitas has developed a system of pencil-shaped “light rods” that allow more light to filter through the pond scum. That means the algae can grow thicker and up to a meter deep, says Weaver, rather than the 3 to 5 centimeters where algae would typically max out as a result of self-shading.
Bionavitas is calling this system Light Immersion Technology, or LIT. In open ponds — where algae can be grown for biofuels production — the rods distribute sunlight below the surface. For closed bioreactors, used for food-grade algae, Bionavitas fits the rods with LED bulbs that distribute red- and blue-spectrum light. (Weaver says the company has developed the bioreactors using software to control temperature, nutrients, carbon dioxide, airflow and other environmental factors.)
At this point, Bionavitas needs capital for a large-scale demonstration of its technology. Backed by angel investors so far, the company is now negotiating a Series A round to finance an algae-to-biofuel pilot plant within 16 months. Of course, financing for this kind of facility is scarce these days, so that timeline may be ambitious. But Bionavitas has other pots brewing: In addition to building its own biorefineries (likely with partners who specialize in extraction) Bionavitas plans to sell its equipment for biofuels and food-grade algae production, water remediation and carbon capture at power plants or heavy industrial sites.
Interest in the carbon capture side of Bionavitas’s business has shot up recently, largely due to looming carbon pricing legislation and programs in the stimulus package. “If you’re making algae this dense,” Weaver said, “you have to have a CO2 source.” It might as well come from a power plant willing to pay to get rid of it.
Photo credit Bionavitas