Critical analysis of current microalgae dewatering techniques

Oil-accumulating microalgae have the potential to enable large-scale biodiesel production without competing for arable land or biodiverse natural landscapes. However, microalgae harvesting/dewatering is a major obstruction to industrial-scale processing for biofuel production. The dilute nature of microalgae in cultivation creates high operational costs for harvesting, thus making microalgal fuel less economical. Within the last decade, significant advances have been made to develop new technologies for dewatering or harvesting of microalgae. The choice of which harvesting technique to apply depends on the microalgae cell size and the desired product. Microalgae dewatering processes can broadly be classified as primary and secondary dewatering. This article provides an overview of current dewatering techniques along with a critical analysis of costs and efficiencies, and provides recommendations towards cost-effective dewatering.