Production of Hydrogen as a Potential Source of Renewable Energy from Green Algae – A Review

Abstract. Today, as the world is facing a crisis in terms of energy economization, different studies are being carried out to promote different sources renewable energy in future. The objective of this study is to promote one such extremely efficient and clean source of renewable energy – the green algae. The basic principle is – the green algae, e.g. Chlamydomonas reinhardtii can photosynthetically produce molecular hydrogen under sulphur deprived conditions. They offer a biological route to decarbonized hydrogen production via a renewable source, hence strengthening hydrogen’s claim to become the sustainable fuel of the future. Molecular hydrogen is an energy carrier that has the potential to provide the clean energy required for transport, heating and electricity. The hydrogen production is initiated under anaerobic conditions when the hydrogenase enzyme is released. During normal photosynthesis the production of oxygen and hence the presence of oxygen during respiration around the microorganism inhibits the release of hydrogenase enzyme. When the anaerobic conditions prevail, the oxygen release during photosynthesis is consumed by algae itself and hence, hydrogenase is released. Experiments have shown that if the enzyme is added externally, hydrogen production increases 400%. Algal hydrogen production does not generate any toxic or polluting by-products and could potentially offer value-added products derived from algal biomass. We conclude that as this microorganism is abundantly found on the earth (approximately 50,000 microalgae can be caught on an average human finger easily), this non-polluting and clean source of renewable energy is very much capable of meeting with the ever increasing world’s energy requirements in the future