“…Harvesting and dewatering algal biomass is challenging due to the small size of algal cells, density similar to water, and dilute initial concentration (typically around 0.5 g/L from open pond systems). As a result, for some dewatering options the energy input required to harvest algal biomass can approach or exceed the energy content of the biomass [77], and can account for 20% to 30% of the overall cost of renewable fuel production [78] when considering standard approaches taken today, such as centrifugation by itself. Many harvesting and dewatering strategies have been investigated and are currently under development, including settling and gravity sedimentation, screen filtration, membrane filtration, flocculation, centrifugation, dissolved air flotation, filter presses, electrocoagulation, magnetic separation, and ultrasonic separation.…”