ABSTRACT
Sustainable bioenergy and biofuel production from microalgal biomass is an important subject due to the finite and dwindling petroleum fuel reserves. Microalgae produce various macromolecules with potential bioenergy and pharmaceutical applications. Therefore, it is mandatory to explore renewable energy from microalgal biomass. Biofuel production from microalgae suffers from challenges such as the small cell size of the microalgae and their occurrence in aqueous suspension, making cell harvesting and metabolite extraction technically difficult. For the process to succeed, it is mandatory to bioprospect for unique and robust indigenous microalgal strains that are adapted and acclimatized to local physical conditions. High-throughput screening for neutral lipid production is a major step towards the selection of desirable strains for sustainable biofuel production. In this chapter, biotechnical processes such as hydrothermal liquefaction, pyrolysis, gasification, transesterification, supercritical processing, thermal and catalytic cracking and fractionation for the conversion of microalgal biomass to biofuels are described in detail. They are generally used in the petrochemical industry, but these techniques can be adapted for the production of fuels from microalgae. These approaches are sustainable but still require more development to get to the point where bioenergy and biofuels from microalgae can effectively compete with the current fossil-based energy sources.
