Chapter 15 - Biohydrogen from microalgae

Abstract

The exponential rise in global energy demand, rapid exhaustion of fossil fuel reserves, and environmental damage have necessitated the introduction of sustainable and renewable energy sources. Hydrogen has garnered considerable interest as a propitious energy alternative due to its high calorific value and generation of clean oxidation products. Compared to thermochemical technologies, the biological method is a more practical approach for hydrogen production because it is environmentally benign, less energy-intensive, and can be performed under ambient conditions. Recently, biohydrogen production from microalgae has emerged as a promising method of green energy generation. This is due to the inherent attributes of microalgae, particularly higher cell growth rate, superior CO2 fixation capacity, and lower space requirement. Despite all these advantages, the feasibility of microalgal-based hydrogen production processes remains to be commercially certified. This chapter describes methods of hydrogen production from microalgae including photolysis and dark fermentation. The key enzymes involved and different parameters affecting biohydrogen production are discussed, and a compendium of pretreatment techniques used in biohydrogen production process from microalgal feedstock is included. The current challenges and future research areas are critically examined to realize the application of microalgae for biohydrogen production at an economic and industrial scale.