Web exclusive posted Nov. 4, 2008 at 2:57 p.m. CST

A new lipid extraction technology for algae has been developed by Culturing Solutions Inc., according to company Chief Executive Officer Dean Tsoupeis. The process is called ultrasonic cavitation. "There are different varieties of reactors out there that utilize this technology, but ours passes the algae biomass through a chamber and what's called the horn," Tsoupeis said. "The tolerance between the chamber and the horn is very small and, as it passes over that, the cavitation occurs, which creates small bubbles that collapse on a high-pressure cycle."

The process is a violent reaction, essentially, which ruptures the algal cell wall to release the lipids. From there, the material goes to a "special centrifuge" to separate out the oil, water and biomass, Tsoupeis said. After separation, dehydration and evaporation can take place to remove any remaining water in the oil, which can proceed "straight to biodiesel production," he added.

The technology is bench-scale at this point. The company said the next phase is developing a pilot-scale version of the ultrasonic cavitation lipid extraction process.

According to Tsoupeis, there is a synergy between the company's algae harvesting method, called BioFence, and ultrasonic cavitation. "From our harvesting method we have about 20-percent to 30-percent water in the biomass after harvest," he told Biodiesel Magazine. "And we don't need to dewater it prior to cell rupturing. It's a wet process and we utilize the water that's in the slurry as a solvent pretty much – that's where the cavitation occurs, it's with the water – so that is what causes the rupturing of the algae cells."