Electrolytic Methods as a Cost and Energy Effective Alternative of Harvesting Algae for Biofuel

Process variables of electrolytic technology to reduce the energy consumption of harvesting Nonnocloropsis salina were investigated including electro-coagulation, electro-floatation, and electro-flocculation. Electro-coagulation and electro-flocculation showed significant cost savings, however electro-floatation did not. The objectives were to determine the effects of electrode material, pH adjustment and electro-polymer addition for electro-coagulation and determine the performance characteristics for electro-coagulation and electro-flocculation. Both treatments proved to be competitive with the energy consumption of a centrifuge. The best electrolytic treatments were electro-coagulation with aluminum and nickel electrodes. Energy requirements at optimum conditions were 239 and 344 kWh/ton. The best treatment combination using electro-flocculation was 432 kWh/ton with no electrode consumption, which could lead to potential cost savings.