Australian partnership breeds new algae harvesting system
After two years of research and development performed in part with Australia’s MBD Energy and James Cook University, OriginOil has designed and built a three part algae harvesting system that will be commercially available in early 2012. The system is trademarked the AlgaeAppliance and is a downsized version of the harvesting system employed at the MBD pilot scale plant in Australia. As Bill Charneski, OriginOil’s senior director of product engineering, told Biodiesel Magazine, this is a system the company believes rivals any off-the-shelf appliance, such as a refrigerator, which anyone can put in their house (or in this case, a production facility) to do a given job.
“What we realized,” he said, “is that in the algae marketplace there are very few people that have any amount of algae,” adding that when the company talks to various growers, most are growing between 10,000 and 20,000 gallons of algae. Because the systems developed for MBD are too large for most growers, Charneski explained that a smaller system was needed. The device they created can operate at a very low range, somewhere between two liters to 20 liters of algae slurry per minute to remove 90 to 95 percent of the water.
The AlgaeAppliance works in three ways. Because the algae cells in the water are negatively charged, every algae cell repels away from the other. “It’s kind of like a magnet,” Charneski explained. “If you put two negatives together, they won’t attract.” To alter the charge of the algae cells, the harvesting system employs an electromagnetic pulse that neutralizes the charge. After performing the EMP, the algae cells would naturally float to the bottom of whatever vessel the algae was housed in, but during the second stage of the harvesting system tiny air bubbles are injected into the water, floating the algae cells to the surface. “The water goes out the bottom,” Charneski said, “the algae cells become a mat at the top and you can rake out the algae cells from the top of the tank.” The final stage of the process, which may or may not be performed based on the user’s preference, is another EMP that will break open the algae cell membrane, releasing the lipid oil inside the cells.
The system runs as a continuous process and uses zero chemicals, can handle any type of algae strain and comes as a single unit that only needs the algae water input plugged in on one side, and the power source plugged into another. The initial work, including the basic engineering of the system, was all done in-house at the company’s Los Angeles facilities, but the final engineering of the systems were performed by Pace Engineering, a wastewater treatment specialist. Although the AlgaeAppliance is suited for lower inputs, systems in Australia have run as high as 300 gallons per minute.
Charneski said that the company hopes the harvesting system will help the marketplace develop a greater supply of wet biomass, something he also noted is a feedstock the U.S. DOE is looking at. According to Charneski, the DOE’s push to create uniform specifications for biomass like those seen in the petroleum industry for different products will help growers and manufacturers create processes for particular specifications. One of those specifications could be the algae uniform intermediate feedstock (UIF), which is what the AlgaeAppliance produces.