Wiesbaden, Germany – May 7, 2025. The EU-funded FlashPhos project convened a hybrid workshop at Dyckerhoff’s cement plant to explore the integration of phosphorus recovery technology into the cement industry. The event brought together experts from across Europe to discuss how FlashPhos by-products, such as slag, process heat and synthetic fuel gases, can be meaningfully used within cement production.
FlashPhos is developing a novel thermochemical process to recover high-purity white phosphorus from sewage sludge, while also generating reusable by-products like mineral slag and fuel gases. The workshop examined both material compatibility and energy integration with existing cement production processes.
Key presentations were delivered by Marcus Paul (Dyckerhoff), Christian Schmidberger (University of Stuttgart), Sabrina Frühauf (A TEC), and Stefan Papkalla (VDZ). The presentations focused on alternative raw materials in cement, emissions reduction pathways, process integration, and thermodynamic impacts of introducing FlashPhos outputs into cement kilns.
A highlight came from VDZ, representing the German cement industry. Stefan Papkalla detailed the energetic impacts of FlashPhos fuel gas integration. For phosphorus production of 5,000 tonnes per year, the gas flow rate would amount to about 60% of the raw gas volume in a typical cement plant. This could significantly alter heat transfer and thermal requirements in the preheating phase. However, if the fuel gases are considered as renewable, CO₂ emissions per unit energy could be cut by as much as 64%. Utilising the excess heat for sewage sludge drying was highlighted as a critical strategy.
Marcus Paul (Dyckerhoff) emphasised the transformation underway in the cement and concrete sectors: from reducing CO₂ emissions to rethinking raw material inputs and entire process chains. He presented the need for rethinking the entire cement production process, including the integration of alternative raw materials like FlashPhos slag. Initial tests showed that cements blended with this slag demonstrate encouraging activity indices and performance metrics.
An open discussion followed, covering future integration scenarios, energy balancing, hydrogen co-production options, and positioning FlashPhos within broader waste management and circular economy systems. Market factors, such as the current price of white phosphorus were also considered in the discussion. The event closed with an on-site plant tour for physical attendees, providing insight into cement manufacturing processes and potential touchpoints for integration.
The event was jointly organized by Dyckerhoff, Steinbeis Europa Zentrum, VDZ Technology gGmbH, A TEC Production and Services GmbH and Italmatch Chemicals.
FlashPhos continues to bridge innovation with industrial implementation, aiming for a scalable, circular and climate-friendly phosphorus recovery model.
For more information, visit: www.flashphos-project.eu
For further information contact
Christian Schmidberger
Researcher & FlashPhos Project Coordinator
University of Stuttgart, Institute of Combustion and Power Plant Technology
christian.schmidberger@ifk.uni-stuttgart.de