Conventional drying methods to algal biomass: Their applications and recent advances

In the extraction of intracellular metabolites from algae for nutrition or biofuel production, two crucial processes are microalgae drying and membrane cell disruption. However, drying microalgal biomass is a significant economic constraint, accounting for up to 75% of the overall cost. This chapter provides an overview of the physical principles governing the drying process of algae and also discusses the latest advances in mechanical, chemical, and biological cell-disruption methods, which can be carried out on either dry or wet laboratory settings. In this chapter, various conventional and advanced drying methods, such as vacuum shelf drying, spray drying, microwave drying, convective drying, freeze-drying, and solar drying, are examined. The chapter also outlines nonmechanical membrane cell disruption methods as disruptive technologies and compares them with mechanical drying methods. The advantages and limitations of technological advancements are highlighted, with a particular focus on their cost-effectiveness and energy efficiency.