Optimal design of a low-carbon concrete production plant considering variable material composition and electricity prices

Recycled belite cement clinker (RC-BCC) can partially replace conventional Portland cement to produce low-carbon concrete. We determine the optimal design of a low-carbon concrete production plant and analyze its demand response potential through process scheduling under time-varying electricity prices. To this end, we formulate and optimize an integrated design and scheduling model, combining different technologies for rotary kiln heating, carbon capture and utilization (CCU), and fuel switching. Compared to concrete production from 100% Portland cement, the global warming impact (GWI) is reduced by 27 - 65% at a 50% RC-BCC replacement level, depending on the kiln heating technology, fuel type, and carbon intensity of the electricity mix, highlighting the strong mitigation potential of material substitution and CCU. Across the investigated temporal aggregations of electricity price time series data, flexible operation reduces electricity costs by 2.2 - 2.8% for the electrically-heated rotary kiln and by 13.4 - 18.2% for the oxyfuel-fired rotary kiln with biomass. The corresponding load shifting amounts to 3.7 - 5.3% and 25.0 - 30.6%, respectively. ... mehrHowever, the total annualized cost (TAC) remains similar to the non-flexible process due to the additional capital investment requirements. The results show that RC-BCC is a promising technology for greenhouse gas (GHG) reduction and material circularity in cement production.