An Organic Solvent-Flocculant Based System for Chemical Dewatering of Algae

Abstract

The concentration of algal water in a raceway pond is around 0.5-1 gram of whole cell biomass per unit of volume (liter) of liquid. Because of its dilute nature, dewatering microalgae suspensions can account for a significant portion of downstream processing costs - and thus is a significant challenge for the sustainability of industrial scale algal processes. The Solvent Phase Algal Migration (SPAM) process presented here is a technique designed to separate suspended algal cells from their aqueous phase to a solvent while simultaneously displacing water. This investigation evaluates the dewatering performance of five factors pertinent to the SPAM process: algal surface modifier type, algal surface modifier concentration, solvent fraction, migration time, and initial algal broth concentration. The investigation revealed that the initial algal broth concentration, type of surface modifier and solvent fraction significantly affected the level of algal migration during the SPAM process.