ABSTRACT
The recovery of microalgal biomass from low concentration suspensions is essential for processing into biomass and value-added products. The processes for biomass harvesting, separation and drying are mostly classical unit operations. The common operations for cell separation are solid–liquid separations: filtration, sedimentation, flotation and centrifugation. Filtration is the process where the particles are mechanically retained by a porous barrier while the fluid passes. Tangential filtration is a process where the liquid flow is parallel to separation medium. Centrifugation is the use of centrifugal force to promote insoluble particles settling in a solid–liquid mixture. Drying is an energy-intensive operation. Therefore, prior dewatering is important for an economic process. Drying is the removal of water by means of thermal energy. The process is relatively straightforward but depends on laboratory experimentation to define adequate processing temperatures and drying kinetics. There are several types of drying, ranging from sophisticated processes where the biomass can be freeze or spray dried, to relatively simple solar drying.
