Fraunhofer IKTS Develops Climate-Neutral Lime Production System

The construction materials sector is a significant contributor to global greenhouse gas emissions, with lime and cement production being particularly intensive in energy use and CO2 release. Traditional lime production involves a calcination process that releases substantial amounts of CO2 directly from the material itself, making it difficult to decarbonize solely through fuel switching or electric furnaces.

To address this challenge, researchers at the Fraunhofer Institute for Ceramic Technologies and Systems (IKTS) are developing a novel membrane reactor combined with a sealed electric furnace. This system aims to capture the CO2 generated during lime calcination. The captured CO2 is then reacted with green hydrogen to produce methane, which is subsequently broken down through pyrolysis into hydrogen and elemental carbon (carbon black).

This process, termed carbon capture and utilization (CCU), not only drastically reduces emissions from lime plants but also recovers valuable raw materials. The elemental carbon can find applications in industries such as chemical manufacturing or agriculture as fertilizer. The hydrogen produced is recirculated back into the plant, contributing to a more closed-loop system.

Project partners HySON have successfully tested the membrane reactor concept, and Johann Bergmann GmbH & Co. developed the electric furnace. The Fraunhofer IKTS team plans to scale up the technology with industrial partners. They believe this approach offers significant potential not only for lime production but also for sectors like cement manufacturing and waste management.