Hydrogen made from biomass, with the CO₂ released during production captured and stored underground, can remove more greenhouse gases from the atmosphere than the whole supply chain emits. That is the central finding of a life cycle assessment by researchers at Jeonbuk National University in South Korea, published in Bioresource Technology. The size of the benefit, however, depends heavily on two things: where the plant gets its electricity, and how the biomass is sourced.

What the researchers looked at

The approach is known as bioenergy with carbon capture and storage (BECCS). Organic material – in this case wood pellets – is converted into hydrogen, and the CO₂ released in the process is captured and stored permanently. According to the university’s summary on Tech Xplore, the assessment covered the entire chain: biomass supply, transport, hydrogen production and carbon storage.

The team compared two configurations, each producing 4.2 tonnes of hydrogen per day from 100 tonnes of wood pellets: one drawing electricity from the power grid, and one self-sufficient plant that generates its own electricity from additional biomass and heat recovered from the process.

The results

  • Both configurations are net-negative: −17.19 kg CO₂-eq per kg of hydrogen for the grid-connected plant and −36.56 kg CO₂-eq per kg for the self-sufficient plant.
  • Better than renewable electrolysis in the carbon balance: in the authors’ comparison, the two BECCS systems come out 18.69 to 38.06 kg CO₂-eq per kg of hydrogen lower than the renewable-based hydrogen pathways they assessed – because electrolysis can approach zero, but cannot go below it.
  • Conversion efficiency matters most: the hydrogen conversion ratio was the dominant factor for the global warming potential.
  • Climate is not the only impact: the grid-connected plant showed significantly higher burdens in other categories, such as terrestrial acidification and freshwater eutrophication, mainly due to its electricity-intensive processes.

The study’s first author, doctoral researcher Ha Eun Lee, stresses that the electricity supply strategy has a decisive influence on the environmental performance, and that reliable carbon-negative results require efficient processes, clean energy and responsible biomass sourcing.

The caveats

This is a model-based life cycle assessment, not data from an operating plant, and the results hold under the study’s assumptions. The authors’ sensitivity analysis shows that net-negative feasibility is highly contingent on the biogenic emission factor – in other words, on how the biomass is grown, harvested and accounted for. The negative balance also only holds as long as the stored CO₂ stays stored. And the mass yield is modest: 100 tonnes of pellets for 4.2 tonnes of hydrogen. Sustainable biomass is a limited resource, so BECCS hydrogen will remain one building block among several, not a bulk solution.

Why it matters for Switzerland

The Federal Office for the Environment is clear that Switzerland can only reach net zero by 2050 with carbon capture and storage (CCS) and negative emission technologies (NETs) for hard-to-avoid emissions. According to the long-term climate strategy, around 12 million tonnes of CO₂ per year will have to be stored with CCS and NETs by 2050 – almost 30% of today’s Swiss greenhouse gas emissions. Plants that deliver negative emissions and a useful energy carrier at the same time are therefore of direct interest. The current revision of the CO₂ Ordinance already opens a route for BECCS as stand-alone offset projects, as we described in our post on the CO₂ Ordinance consultation.

The Power-to-X perspective: store or recycle?

A BECCS hydrogen plant produces exactly the two feedstocks that renewable fuels and chemicals are made of: hydrogen and a concentrated stream of biogenic CO₂. Storing that CO₂ creates negative emissions. Recycling it into eMethanol, eSAF or other renewable fuels instead displaces fossil carbon – that is defossilisation. Both are needed, and the choice should depend on the climate benefit per tonne, not on regulatory preference.

Biogenic CO₂ is only one of three sources of recycled CO₂, alongside atmospheric CO₂ from direct air capture and industrial CO₂ (CCU). Given how limited sustainable biomass is, Switzerland will need all three. What counts is that recycling displaces fossil carbon and does not create an incentive to extract more of it. Rules that reward CO₂ storage while ignoring CO₂ recycling miss half of the opportunity.

Get involved

Are you working on hydrogen, carbon capture or renewable fuels in Switzerland? Join the Swiss Power-to-X Collaborative Innovation Network – see our members or contact us at info@power-to-x.swiss.

Sources: Ha Eun Lee, Jester Lih Jie Ling, See Hoon Lee: Life cycle greenhouse gas reduction in bioenergy with carbon capture and storage processes for green hydrogen production, Bioresource Technology (2026); Tech Xplore (5 November 2026); Federal Office for the Environment: Roadmap carbon capture, removal and storage, CO₂-Entnahme und -Speicherung.

🤖 AI transparency: This text and its visual were created using AI, reviewed and approved by a human.