Development of algae for the production of bioethanol, biomethane, biohydrogen and biodiesel

Microalgal biofuels are a viable alternative for clean, economical and sustainable sources of energy. The research and development of micro-algae needs a massive boost to ease the technical difficulties to overcome the large cost advantage of other biofuel feed stocks. It is a large source of biomass on non-arable lands and capture of CO2. Lipids produced from algae contain saturated and polar lipids, which are suitable for use as a fuel feedstock and it exceeds the best producing oil crops. It has been found that representatives of green and diatom microalgae are the most promising producers of TAGs, the highest content of which (40–60%) has been found in diatom microalgae. This paper discusses current knowledge on different techniques for microalgal biomass production, harvesting and lipid extraction methods. The paper also discusses biodiesel production via transesterification of the lipids and other biofuels like biomethane, biodiesel, bioethanol and biohydrogen depending on the species as well as the biorefinery approach. Besides lipid extraction, the byproducts of processed algae can be utilized for many other purposes.