Fraunhofer Institute for Ceramic Technologies and Systems Develops Membrane Reactor for Carbon Capture and Utilization in Lime Production

en.Wedoany.com Reported - German researchers at the Fraunhofer Institute for Ceramic Technologies and Systems (Fraunhofer IKTS) are developing a process for capturing and utilizing carbon dioxide from lime production to reduce greenhouse gas emissions in this sector.

The construction industry contributes approximately one-quarter of global greenhouse gas emissions and is one of the main industrial sources of carbon dioxide. Lime and cement production are typically high-emission processes, with CO₂ content in lime plant exhaust gases often exceeding 40%, and up to 33% in cement kilns. Since a significant portion of these emissions comes from chemical reactions during the calcination of raw materials, climate neutrality cannot be achieved solely through alternative fuels or electric kilns.

In the project named "Green Lime" (Grüner Kalk), researchers have developed a process system combining a specially designed membrane reactor with a sealed electric furnace. In the electric furnace, CO₂ is released from the lime and collected directly. Through pressure control, green hydrogen is metered into the reactor, where it undergoes a chemical catalytic reaction with the collected CO₂ to produce methane. The product gas stream is then dried and pyrolyzed, generating elemental carbon that can be used in the chemical industry or as an agricultural fertilizer additive, while the released hydrogen is fed back into the plant for recycling. According to project leader Dr. Benjamin Jäger, this carbon capture and utilization (CCU) method can significantly reduce emissions from lime plants and generate new raw materials.

The project has completed a proof-of-concept for the reactor in collaboration with the partner HySON – Institute for Applied Hydrogen Research Sonneberg gGmbH (HySON – Institut für Angewandte Wasserstoffforschung Sonneberg gGmbH), with Johann Bergmann GmbH & Co. leading the development of the new electric furnace. In the next phase, the team plans to work with industry partners to scale up the technology to industrial levels. The project is funded by the German Federal Ministry of Research, Technology and Space (BMFTR). Beyond lime production, researchers believe the membrane reactor technology has potential applications in the cement industry and waste management, particularly in sectors where process-related CO₂ emissions cannot be systematically avoided.