Trends in dark biohydrogen production strategy and linkages with transition towards low carbon economy: An outlook, cost-effectiveness, bottlenecks and future scope

The conventional fossil fuel showed a persistent and intense decline steadily over the past two decades have led to global deterioration of limited sustainable energy supplies. Furthermore, price fluctuations and its serious ecological consequences had piqued the interest of researchers mostly in domain of alternative renewable energy. Among all existing fuels, biohydrogen is documented because of its carbon-neutral, simple and sustainable output, low carbon emissions, and large energy density. Hydrogen (H2) generation from dark fermentation of biowaste is an enticing sustainable method which promotes in the creation of low carbon economy. This review details the overview of hydrogen yield form renewable feedstock through dark fermentation. It also detailed the recent trends such as pretreatment, addition of various additives, integrated options, etc., employed towards the enhancement of fermentation process to enrich the hydrogen production. Discussion about the inhibitory substances that affects the performance of fermentation process was incorporated. In addition, it elaborates the economic feasibility, challenges and limitation of the process along with future scope for the development of sustainable hydrogen economy.