Harvesting and Downstream Processing—and Their Economics

Harvesting of dilute cultures of algae from large volumes of culture needed for production of biofuels and bioproducts is a substantial hurdle to the economic viability of algal biofuels. While centrifugation and sedimentation are already scaled to volumes that would allow direct application to algal biofuel production, their economics to the production of biofuel are not favorable. The industry has reevaluated the existing technologies and continues to innovate around the harvesting of microalgae for biofuels and bioproducts. This review discusses the historical approaches and recent advances while comparing and contrasting the different methods. An engineering estimate of comparative costs is also provided.