Valorization of microalgal biomass for biofuels

In recent years, environmental, health, and social challenges have caused a shift toward novel energy sources and biofuels. Under this scope, microalgae have received significant attention as promising substrates for third-generation biofuels, effectively deviating from fossil-based sources. Microalgal biofuels, including biodiesel, biogas, biohydrogen, bioalcohols and biocrude oil, can be derived through biochemical and thermochemical conversion. However, several constraints have to be addressed to reduce production costs and make industrial applications feasible. In this chapter the various types of microalgal biofuels are described, emphasizing the commonly used species and applied conditions, along with the downstream processes commonly followed. Furthermore, life cycle analysis and techno-economic aspects of microalgal biofuels are discussed, while the prospects for cost-effective biofuels are also highlighted. Lastly, directions for future work are provided to establish advanced processes with multiple environmental and bioenergy outcomes.