The energy transition requires new solutions for storing renewable energy. The technology start-up Cairos has developed a groundbreaking methanation technology that converts biogenic CO2 into renewable synthetic natural gas (BioSNG) using green hydrogen. This efficient process was researched over ten years at the University of Leoben and a patent has been filed. Thanks to their high power density, the compact and modularly scalable methanation reactors enable the economical production of green gas.
A milestone in the energy transition
“Our vision is to replace fossil natural gas with economically produced, renewable gas,” explains Dr. Andreas Krammer, co-founder of Cairos and research associate at the Chair. “Our innovative methanation process makes it possible to connect biogas plants directly to the existing gas grid without complex CO2 separation – with twice the bio-methane yield compared to conventional membrane processes.”
By combining biogas plants with the processes of electrolysis and methanation technology from Cairos, biogenic residues and renewable electricity can be efficiently converted into BioSNG that can be fed into the grid.
Prof. Markus Lehner, host and mentor of the start-up, emphasizes the high future demand for green gases, especially for the energy-intensive industry in Austria: “The technology from Cairos significantly increases the proportion of renewable gas produced in Austria and thus contributes to a significant increase in self-sufficiency in Austria”.
“We need to use all available resources – now and even more in the future. This technology therefore represents an important pillar in the future energy industry in order to use surplus electricity and to generate valuable and, above all, storable energy from the available CO2,” explains Dipl.-Ing. Bernadette Mauthner, Managing Director of Biogas Bruck / Leitha GmbH.
Scalable technology with high market potential
Cairos pursues a scalable business model that includes engineering services, methanation hardware and specially developed control software.
“With our technology, we can not only increase efficiency, but also reduce production costs through standardized and modularly expandable systems,” emphasizes co-founder Martin Peham. “Our goal is to deliver methanation plants in the mid double-digit megawatt range by 2030 in order to make a significant contribution to the defossilization of the gas infrastructure.”
The market for BioSNG is enormous: in Europe alone, the biogas industry is facing a transformation. With the expiry of subsidies for the conversion of biogas into electricity, thousands of plant operators are being forced to invest in new technologies. Cairos offers an economical alternative for feeding biogas directly into the gas grid.
Pilot project as a springboard to commercial implementation
As part of an FFG Spin-off Fellowship, a pilot project on a 200-kilowatt scale will be carried out at the Bruck/Leitha biogas plant. The first fully commercial plant with an output of 2 to 4 megawatts is to go into operation at a pilot site by 2027. Cairos then plans to massively scale up production in order to provide methanation plants throughout Europe.
Green drilling rigs as a vision for the future
Cairos’ vision is to create decentralized “green drilling rigs” by coupling methanation plants with PV and wind farms. “Our approach combines the cheapest source of electricity in Europe – PV power – with our highly flexible methanation technology. This creates a reliable, renewable gas supply that creates energy independence and increases resilience to crises,” emphasizes Krammer.
With the ongoing scaling of the technology, Cairos is making a decisive contribution to the defossilization of the gas infrastructure and to Europe’s sustainable energy supply.
[Source: Montanuniversität Leoben, News, March 12, 2025]
