Recent trends and technological advances in sustainable microbial biohydrogen production: a review

The growing demand for sustainable energy resources today has significantly enhanced the need for the green energy economy. It is anticipated that this demand will rise to about 212 Mt due to the world’s energy shift by 2030. Advancement in the field of biohydrogen is emerging as a promising substitute for energy carrier due to its higher energy content, low environmental impact, lower energy input and various functions under mild conditions. Further, as a study towards the suitability in production of microbial biohydrogen, variety of feedstocks, including food wastes, crop residues, lignocellulosic biomass and industrial waste products are utilized. Conversion of diverse waste materials into biohydrogen is a promising approach in renewable energy research. Though many researchers have focussed on the area of microbial biohydrogen production technologies via dark and photo fermentation, certain challenges such as low hydrogen yield, system instability and challenges are still unaddressed towards large scale production. Thus, the present review focuses on the recent advancement in integrated technologies like dark and photo fermentation, microbial electrolysis and nanotechnology to improve biohydrogen yield process efficiency as well. The review supports biological hydrogen production routes, reactor designs, purification methods with few impacts of inhibitory compounds on yield and the role of engineering and enhancing process performance using engineered microbial strain combined with economic feasibility for large scale applications. Moving towards the path of sustainability, the article highlights further research and policies for the commercial and viable applications of biohydrogen.