Biohydrogen from agricultural waste
A biological route to clean hydrogen that also solves one of India’s biggest waste problems.
Let nature’s microbes make the fuel
Biohydrogen is hydrogen produced from organic material, such as agricultural waste, through a biological process. Unlike electrolysis, which splits water into hydrogen and oxygen using large amounts of electricity (often from non-renewable sources), biohydrogen relies on microorganisms that break down plant matter and release hydrogen.
The result is a lower-energy route to clean hydrogen that also manages agricultural waste, so every tonne of residue used is a tonne kept out of the fire.
What goes in, what comes out
- In: paddy straw, wheat straw and other crop residue
- Process: pre-treatment, hydrolysis, dark fermentation, purification
- Out: clean hydrogen gas
- Also out: by-products that can be used further, so little is wasted
Inside the process, step by step
Select a step, or use the arrow keys, to explore.
Collecting crop residue
Paddy straw, wheat straw and other agricultural waste are gathered after harvest — material that would otherwise be burnt in the field.
81% of paddy straw is burnt in fields in India (ICAR)Opening up the fibre
Straw is cleaned and size-reduced, then pre-treated to loosen its tough lignin layer so the cellulose inside can be reached. This step decides how much of the residue can later become hydrogen.
Lignocellulose: cellulose + hemicellulose + ligninReleasing natural sugars
Cellulose and hemicellulose are broken down into simple sugars. These sugars are the food for the microbes in the next step.
Plant fibre → fermentable sugarsMicrobes make hydrogen
In a sealed, oxygen-free bioreactor, hydrogen-producing bacteria digest the sugars at moderate temperatures, releasing hydrogen gas. It is called “dark” fermentation because no light is needed.
A biological process — no water-splitting electricitySeparating clean hydrogen
The gas from the reactor is a mix, mainly hydrogen and carbon dioxide. It is cleaned and dried to separate usable hydrogen.
Biogas mixture → purified H₂Using hydrogen and by-products
Hydrogen can serve as a clean fuel for industry, power and mobility. The remaining liquid and solids can be treated further, for example for biogas or as organic soil input, so little is wasted.
Hydrogen from biomass is recognised under India’s Green Hydrogen StandardBiohydrogen and electrolysis
Both make hydrogen. They start from very different places.
| Biohydrogen (dark fermentation) | Water electrolysis | |
|---|---|---|
| Raw material | Agricultural and organic waste | Purified water |
| Main energy input | Energy stored in the biomass; microbes do the conversion | Large amounts of electricity |
| Operating conditions | Moderate temperature and pressure | Depends on electrolyser type |
| Waste management | Uses residue that would otherwise be burnt | None |
| Rural value | Creates value around farm residue | Limited |
Green Hydrogen Mission
Approved in January 2023 with an outlay of ₹19,744 crore, the mission targets 5 million tonnes of green hydrogen production a year by 2030.
Biomass is recognised
India’s Green Hydrogen Standard covers hydrogen made from biomass, with a limit of 2 kg CO₂ per kg of hydrogen, averaged over 12 months.
Abundant residue
Around 81% of paddy straw and 48% of wheat straw in India is burnt in fields, according to ICAR. That is feedstock waiting to be used.
Common questions
What is biohydrogen?
Hydrogen gas produced by living microorganisms from organic material. In Kalon Energy’s case, that material is agricultural waste such as paddy straw.
Why is it called “dark” fermentation?
Because the bacteria that produce hydrogen in this process work without light, in a sealed, oxygen-free reactor. Some other biological routes, such as photo-fermentation, need light.
Is biohydrogen “green” hydrogen?
India’s Green Hydrogen Standard includes hydrogen produced through biomass conversion, provided the total emissions stay within the limit set by the standard.
What happens to the leftover material?
The liquid and solids left after fermentation can be treated further, for example to produce biogas or to return organic matter to the soil, so that as little as possible is wasted.
Where is Kalon Energy’s work based?
Our registered office is in New Delhi and our project office is in Lucknow, Uttar Pradesh — close to the farming regions where crop residue is produced.
Be part of the clean hydrogen revolution.
Farmers, students, researchers, industry and investors — there is a place for you in this work.