A review of bioreactor configurations for hydrogen production by cyanobacteria and microalgae

The need for cleaner energy as a sustainable alternative instead of fossil fuels has led to a plethora of research on biological H2 production by microalgae and cyanobacteria. These species have a great potential to produce hydrogen in photobioreactors acting as a closed system that provides suitable conditions for algal cultivation. This review provides an overview of the requirements for green algae and cyanobacteria growth and focuses on the conditions required for hydrogen production. Also, the common types of bioreactors used for hydrogen production were critically assessed in terms of microbial growth and hydrogen production. Culturing these microorganisms within an electrochemical unit is a promising approach to increase biohydrogen production. The inclusion of nanoparticles is also an emerging technique to improve light scattering in photobioreactors.