Green Innovation and FUELFLEX® Pyrolyzer - presentation by Lars Skaarup Jensen

The cement industry has identified three primary decarbonization pathways with measurable impact potential: clinker substitution (30-40% reduction), clinker decarbonization through fuel substitution (10-15%), and efficiency improvements (5-10%). New technologies, particularly Carbon Capture, Utilization and Storage (CCUS), offer an additional 30-40% emissions reduction potential. While significant progress has been made with technologies like the FUELFLEX® Pyrolyzer, achieving net zero will require rapid scaling of these solutions alongside implementation of carbon capture technologies. Our collaborative research projects demonstrate industry commitment, but accelerated deployment remains essential to meet 2050 targets.

The FUELFLEX® Pyrolyzer utilizes 800°C hot meal from the lowest preheater cyclone as a gasification medium for alternative fuels. Our innovative pulse aeration technology makes the meal flow like a liquid, creating highly reactive gases that naturally reduce NOx without ammonia injection. The system features continuous debris removal through twin drain gates that prevent blockages. Unlike conventional approaches, the FUELFLEX® avoids costly calciner extensions while enabling higher alternative fuel substitution rates and delivering superior NOx reduction performance, as demonstrated at Mannok Cement.

Despite initial operational success at startup, we encountered a significant challenge after approximately two weeks when the pyrolyzer began to block with debris from alternative fuels. Wires, stones, and other contaminants sedimented in the highly corrosive environment (800°C with sulfur and chlorine), creating blockages. This necessitated a comprehensive redesign of the pyrolyzer's bottom section and aeration system, requiring approximately eight months to resolve. The redesign implemented second and third-generation aeration systems to ensure reliable operation, demonstrating our commitment to developing practical, commercially viable solutions.

Achieving 99% alternative fuel substitution required a systems approach beyond the pyrolyzer technology alone. We implemented three key optimizations: 1) De-bottlenecking the mechanical feed system and enhancing the Pfister feeders to increase alternative fuel capacity; 2) Installing the FEEDflex® upgrade to the coal feeder, improving turndown ratio from 1:10 to 1:100, enabling minimal standby coal while maintaining rapid ramp-up capability; and 3) Upgrading the PXP process control system to maintain optimal process stability with minimal coal usage (reduced to 0.2 tons per hour). This integrated approach demonstrates the importance of considering the entire system when maximizing alternative fuel usage.

The FUELFLEX® Pyrolyzer delivered significant and measurable NOx reduction. Prior to installation, Mannok required approximately 214 liters per hour of ammonia water for NOx compliance while running at 50% alternative fuel mix. Even at 80% alternative fuel directly to the calciner, they still needed 159 liters per hour of ammonia. After installing the FUELFLEX® Pyrolyzer, ammonia water usage was eliminated completely while reducing stack NOx to 358 mg NO₂/Nm³ at 10% O₂—substantially below regulatory limits. This demonstrates how our technology transforms relatively unreactive alternative fuels into highly reactive fuel streams capable of efficiently reducing NOx.

The FUELFLEX® Pyrolyzer delivers multiple financial benefits. The system eliminates the need for costly calciner extensions and removes ammonia water expenses (previously 214 liters per hour at Mannok). Additionally, coal usage was reduced from 7.4 to 1.6 tons per hour, providing further cost savings. The technology enables increased utilization of alternative fuels, which typically cost less than fossil fuels. While specific investment figures are project-dependent, the Mannok installation demonstrates a commercially viable approach delivering both environmental and economic returns, making it an attractive option for cement producers pursuing decarbonization.

The FUELFLEX® Pyrolyzer technology is highly transferable across diverse cement operations. Our second installation is currently being commissioned at Continental Cement in Iowa, USA, which has different fuel types and process configurations compared to Mannok. The system's design allows integration within existing preheater towers without major structural modifications. The technology has been engineered for flexibility, accommodating various alternative fuel types and plant configurations. This adaptability, combined with our standardized implementation approach, enables efficient deployment across the global cement industry.

FLSmidth Cement is pursuing multiple parallel innovation streams in our decarbonization roadmap. Current initiatives include additional FUELFLEX® installations, with Continental Cement's system commissioning in 2024; calcined clay technology implementation in France (525 tons/day) and Ghana (1200 tons/day); the CO₂ Valorize project developing valuable SCM products from CO₂; EcoClay for electrification of clay calcination; NewCement exploring oxyfuel technology; DETOCS digital modeling for concrete optimization; and concrete recycling initiatives. This comprehensive approach addresses multiple decarbonization pathways simultaneously, reflecting our commitment to developing commercially viable solutions for the cement industry's sustainability transformation.