Cost-Effective Downstream Processing of Algal Biomass for Industrial-Scale Biofuels Production

Presently, the availability of limited fossil fuel resources and environmental pollution are significant international concerns. Algae have entertained a lot of attention in modern times because they are the source of many biomolecules that have various industrial applications from pharmaceuticals to fuels. However, a considerable amount of research must be conducted in order to leverage these bioresources for large-scale production of algal biomass. Furthermore, research on the downstream processing perspectives of these algae metabolites is limited. The structure and composition of the cell wall of both micro and macro algae make the extraction and purification of these products difficult. Downstream processing (DSP) is a series of cascading unit operations performed after upstream processes to improve the final product's concentration and purity. The nature of the product (intracellular or extracellular, physicochemical characteristics), choice of biomass resources, fermentation procedures (solid state or submerged), and types of catalysts (types of microorganisms, enzymes) used all have a major influence on the specific and cost-effective downstream processes. This chapter provides a comprehensive review of techniques for biometabolite extraction, separation, and purification from algae for commercial-scale biofuel production employing a biorefinery approach.