Generating green hydrogen from biomass!

A team of researchers at the Indian Institute of Science (IISc) in Bengaluru has developed a technology to produce hydrogen from biomass. India uses nearly 50 lakh tonnes of hydrogen for various processes in different sectors, and the hydrogen market is expected to grow substantially in the coming years, according to S Dasappa, Professor at the Centre for Sustainable Technologies, and Chair of the Interdisciplinary Centre for Energy Research at IISc., who led the research efforts.

The process consists of two steps. In the first step, biomass is converted into syngas – a hydrogen-rich fuel gas mixture – in a novel reactor using oxygen and steam. In the second step, pure hydrogen is generated from syngas using an indigenously developed low-pressure gas separation unit.

Both these technologies, developed in Dasappa’s lab, ensure that this process is a highly efficient method of generating green hydrogen – it produces 100 g of hydrogen from 1 kg of biomass even though only 60 g of hydrogen are present in 1 kg of biomass. This is because in this process, steam, which also contains hydrogen, participates in both homogeneous and heterogeneous reactions (in homogeneous reactions, reactants are in a single phase whereas in heterogeneous reactions, the reactants are in two or more phases).

The production of green hydrogen using this process is environmentally friendly for another reason – it is carbon negative. The two carbon-based by-products are solid carbon, which serves as a carbon sink, and carbon dioxide, which can be used in other value-added products.

This indigenous technology is a step towards achieving the goal of Atmanirbhar Bharat, Dasappa said. The technology also dovetails nicely with the National Hydrogen Energy Roadmap, an initiative of the Government of India that aims to promote the use of hydrogen as a fuel and reduce dependence on fossil fuels, he added.