Emerging technologies for sustainable production of biohydrogen production from microalgae: A state-of-the-art review of upstream and downstream processes. (December 2021) - Kumar Sharma, Amit
Graphical abstract: Highlights: Microalgae-based BioH2 production is a novel, green and eco-friendly approach. Upstream and downstream pathways involved in microalgal BioH2 production are explored. Genetic and metabolic engineering is the most promising tool to boost BioH2 production. Technical and scientific obstacles of microalgae BioH2 systems are addressed. Abstract: Biohydrogen (BioH2 ) is considered as one of the most environmentally friendly fuels and a strong candidate to meet the future demand for a sustainable source of energy. Presently, the production of BioH2 from photosynthetic organisms has raised a lot of hopes in the fuel industry. Moreover, microalgal-based BioH2 synthesis not only helps to combat current global warming by capturing greenhouse gases but also plays a key role in wastewater treatment. Hence, this manuscript provides a state-of-the-art review of the upstream and downstream BioH2 production processes. Different metabolic routes such as direct and indirect photolysis, dark fermentation, photofermentation, and microbial electrolysis are covered in detail. Upstream processes (e.g. growth techniques, growth media) also have a great impact on BioH2 productivity and economics, which is also explored. Technical and scientific obstacles of microalgae BioH2 systems are finally addressed, allowing the technology to become more innovative and commercial.