ZEUS joint project: CO2 membrane separation plant goes into operation

The plant recovers up to half a ton of CO₂ per day, which is purified and converted into formic acid. It was built as part of the ZEUS (Zero Emissions throUgh Sector Coupling) joint project, in which several participating partners are testing different technologies for the recovery and use of CO₂ across sectors in order to optimise them for various industries. Construction of the plant, which was created in collaboration with the international technology group ANDRITZ and Gaseo, began in October 2024. It was completed at the end of March 2025 and connected to the exhaust gas path and the SCR pilot plant at the Gmunden cement works. Testing in real operation is scheduled to take place by 2027.

Innovative CO₂ separation using membrane technology

Before carbon dioxide can be converted into formic acid, it must be separated from the flue gas. One approach to separation is membrane technology, which is being tested for the first time in the Austrian cement industry at the Gmunden plant. The flue gas is passed through cylindrical membrane modules with spirally wound membranes inside. The membranes resemble the filter mat of a kitchen extractor fan, but the membrane modules have a much larger surface area thanks to the special arrangement. This enables rapid and selective separation of CO₂ in the smallest of spaces. CO₂ separation using membrane technology takes place in a container developed and built by ANDRITZ, while formic acid production takes place in a tabletop system developed by Gaseo and Rohrdorfer.

CO₂ electrolysis process developed by Rohrdorfer enables formic acid production

In the second step, the captured CO₂ is to be converted into the basic chemical formic acid, which will initially be stored at the Gmunden site. To achieve the targeted production output, a CO₂ electrolysis process developed and patented by Rohrdorfer with a capacity of up to five kilograms of product per hour will be used. This production capacity represents the next expansion stage of the Rohrdorfer process, which has already been demonstrated at the Rohrdorf site with a production capacity of one kg per hour and has been further developed for scaling in the ZEUS project.

Milestone on the way to CO₂-neutral production

Parallel to the membrane separation process in Gmunden, Rohrdorfer is also researching the separation process using amine scrubbing at the Rohrdorf site. "The commissioning of the membrane separation plant in Gmunden is a milestone for us. We can now test the already familiar amine scrubbing process and membrane separation in direct comparison and gain valuable experience for the cement industry," says Dr. Christopher Ehrenberg, Technical Director of the Cement Division at Rohrdorfer. "We want to thoroughly test the two processes by 2027. We are also gathering publicly available data on other promising technologies. Once it has been established which technology is the most efficient, the corresponding separation plant will be built on an industrial scale."

Read the article online at: https://www.worldcement.com/europe-cis/08082025/zeus-joint-project-co-membrane-separation-plant-goes-into-operation/