San Diego-based Global Algae Innovations is reporting an innovative new harvesting technique designed to solve one of the most persistent challenges in turning algae into a sustainable biofuel.
The new technique revolves around a membrane system that could cut the cost of separating water from the feedstock by 99%, once the initial design is scaled up.
“One of the more perplexing problems of the advanced bio-economy is getting algae out of the water or water out of the algae,” Biofuels Digest explains. For algae to become a viable feedstock for food, feed, chemicals, or fuels, production costs will have to fall to US$2,000, and eventually US$500, per ton. But when centrifuges have to remove 50 to 100 tons of water to get one ton of product, “the energy costs are murderous.”
The new technique brings algae concentrations up to 15 to 20%, GAI founder and CEO David Hazlebeck told Digest.
“Membrane technology offers several advantages over competing dewatering strategies, including high reliability, direct scalability, and simple thermal, mechanical, and chemical management demands,” the U.S. National Renewable Energy Laboratory wrote in an assessment of the GAI system. Membrane technology also “produces a filtrate product suitable for recycle, and does not add chemicals to the algal biomass that must be removed later or may negatively impact the value of coproducts.”
Past arguments against membrane-based dewatering systems “have been based on fouling and maintenance/reliability issues that have been observed for other membrane types,” NREL noted. “However, GAI indicated that maintenance and fouling are not typically problematic or costly issues for their process, based on a daily cleaning protocol for the membrane modules.”
While financing for the new system is a “known-unknown,” writes Biofuels Digest Editor Jim Lane, there’s “ample evidence” that the company “has made a substantial breakthrough on harvesting and dewatering. And that’s been a bottleneck for algae development.”