IISc develop tech to generate green hydrogen

Researchers at the Indian Institute of Science (IISc) have developed an innovative technology that can produce hydrogen from biomass. An IISc statement points out that most of the hydrogen currently use comes from fossil fuels through a process called the steam methane reforming route. Now, the IISc team has found a way to extract green hydrogen from biomass, a renewable energy source.

The team was led by S Dasappa, Professor at the Centre for Sustainable Technologies, and Chair of the Interdisciplinary Centre for Energy Research at the IISc. In the statement, Dasappa says that India uses nearly 5 million tonnes of hydrogen for various processes in different sectors, and the hydrogen market is expected to grow substantially in the coming years.

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 … 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, Dasappa adds in the statement. He believes that green hydrogen could be used in several other industries as well — in the steel industry to decarbonize steel, in agriculture to manufacture green fertilizers, and in many sectors currently using hydrogen produced from fossil fuels.  “Moreover, the same platform can be used for methanol and ethanol production,” he pointed out.

The project was supported by the Ministry of New and Renewable Energy and the Department of Science and Technology of the Government of India. The team also acknowledges the support of the Indian Oil Corporation Limited in scaling up the technology to produce 0.25 tonnes of hydrogen per day for use in hydrogen-powered fuel cell buses.

According to a World Bank blog, green hydrogen holds significant promise to help meet global energy demand while contributing to climate action goals. It is produced by using renewably generated electricity that splits water molecules into hydrogen and oxygen. The demand for hydrogen reached an estimated 87 million metric tons (MT) in 2020, and is expected to grow to 500–680 million MT by 2050. From 2020 to 2021, the hydrogen production market was valued at $130 billion and is estimated to grow up to 9.2% per year through 2030. But there’s a catch: over 95% of current hydrogen production is fossil-fuel based, very little of it is “green”. Today, 6% of global natural gas and 2% of global coal go into hydrogen production.

Nevertheless, green hydrogen production technologies are seeing a renewed wave of interest. This is because the possible uses for hydrogen are expanding across multiple sectors including power generation, manufacturing processes in industries such as steelmaking and cement production, fuel cells for electric vehicles, heavy transport such as shipping, green ammonia production for fertilizers, cleaning products, refrigeration, and electricity grid stabilization. Moreover, falling renewable energy prices — coupled with the dwindling cost of electrolyzers and increased efficiency due to technology improvements — have increased the commercial viability of green hydrogen production.

The World Bank blog adds that according to Bloomberg New Energy Finance, if these costs continue to fall, green hydrogen could be produced for $0.70 — $1.60 per kg in most parts of the world by 2050, a price competitive with natural gas. Given this significant growth, the scale of input energy required (22,000 TWh of green electricity to produce 500 million tons of green hydrogen per year), the green hydrogen industry should attract investments. Yet, to date, only a few green hydrogen projects have been successfully brought to market.