Challenges and opportunities in the production of sustainable hydrogen from lignocellulosic biomass using microwave-assisted pyrolysis: A review

Hydrogen is the potential future resource to cater the energy and chemical requirements. Microwave-assisted pyrolysis (MAP) could be the potential technology to obtain green hydrogen from lignocellulosic biomass waste. The proximate and elemental composition varies with the type of lignocellulosic biomass, which influences the yield of hydrogen. In MAP, the operating parameters including microwave power, heating rate, temperature, and susceptor play an important role in hydrogen production. Cellulose, hemicellulose, and lignin present in the lignocellulosic biomass undergo decomposition when they are subjected to MAP. Most importantly, the susceptor material added to the feedstock induces the plasma, which would help the cleavage of the bonds to form hydrogen gas. When the microwave power intensity is high, then the generation of hydrogen would be high. During the MAP, the formed char from the biomass would act as susceptor cum catalyst, hence it further speeds up the hydrogen generation pathways. The energy and time required for the MAP are very less compared to conventional pyrolysis. The present review manuscript would help the research community to understand the possible applications of MAP for hydrogen production.