Biohydrogen production from lignocellulosic feedstock: Abiotic and biotic methods

Bioenergy is known as green energy produced from organic biomass, such as food leftovers, non-edible agri-residues, and municipal wastes through biotic and abiotic methods. Globally, generation of the most common renewable fuels including biohydrogen (bioH₂), biogas, bioethanol, biofertilizers and bio plastics as fossil fuel substitutes by means of circular bioeconomy is gaining tremendous focus in support of environmental concerns. Carbon free bioH₂ is considered as deemed fuel due to its multifaceted applications and potent ecological features. As the present commercial energy manufacturing methods tap on non-renewable fuels and associated high cost, there is an immediate need for full scale sustainable bioH₂ production systems in accordance with regional demand through domestic innovations. Though, research on hydrogen production is not less common via conventional thermo chemical methods, it is essential to understand much regarding biological methods to achieve feasible transition from depleting fossil fuels to eco-friendly renewable energy. Thus, this review primarily focuses on different sustainable approaches for lignocellulosic biomass valorization towards bioH₂ production along with potential thermo chemical approaches. In particular, bioH₂ production from lignocellulosic biomass in the presence and absence of light by photo fermentation and dark fermentation, respectively, reactor configuration, importance of biocatalyst pretreatment and potential methods, and natural and mutant microalgal bioH₂ evolution have been discussed in detail to address their industrial level applicability.