Thermochemical and biological routes for biohydrogen production: A review

One essential energy vector for building a sustainable bioeconomy is hydrogen, which may be obtained from renewable biomass sources. This study discusses many biological routes used in the conversion of biomass to hydrogen, as well as a variety of thermochemical routes such as pyrolysis and gasification. Thermochemical routes include fast pyrolysis, steam and supercritical water gasification, and related processes; biological routes include photo, dark, and mixed fermentation techniques in addition to bio-photolysis processes. Notwithstanding its promise, improving the reliability and selectivity of hydrogen processing is necessary for economically viable industrial uses in the hydrogen economy. The importance of operating conditions, process parameters, variables influencing hydrogen production, parameters of storage methods, hydrogen transportation, separation, and difficulties in producing hydrogen through thermochemical and biological routes are all covered in this paper. It looks at the problems that come with these procedures, highlighting important knowledge gaps that need for more investigation. Combining biological processes with thermochemical pathways can ensure economic sustainability. Both thermochemical and biological routes can help fulfilling future demand for a hydrogen based society.