Macroalgae-derived biohydrogen production: biorefinery and circular bioeconomy

Algae is considered as a promising third-generation biofuel feedstock. Macroalgae is an efficient source of biomass for biohydrogen production. Biohydrogen (H 2 ) is believed as a sustainable and clean energy carrier with high-energy yield. The pretreatment is essential to enhance the hydrolytic process during dark fermentation. During pretreatment, some inhibitory substances are formed and are controlled by detoxification techniques. This review briefly covers the marine macroalgal species, pretreatment methods for biohydrogen production, and inhibitory components formed during the pretreatment. Lastly, this review suggests the techno economic assessment about life cycle, energy, and economic feasibility in biohydrogen production from macroalgae.