Unlocking deep decarbonization of BF–BOF steel mills through CaL-based heat integration: Technical and prospective economic analysis of CCS and CCUS pathways

Reducing CO 2 emissions from iron and steel production is essential to maintain industrial competitiveness and meet climate targets. This study evaluates five low-carbon blast furnace steel plant configurations integrating different CCUS strategies, with emphasis on Calcium Looping (CaL), a CO 2 capture technology offering high heat integration potential. The two most promising configurations were further assessed under 2040 and 2050 conditions using Monte Carlo simulations and global uncertainty analysis. The most integrated option, combining advanced blast furnace operation (oxy-combustion, TGR, and SNG injection) with CaL, achieved CO 2 reductions of up to 81% (1539 kg CO2 /t HM ) for the baseline case, and up to 92% (1750 kg CO2 /t HM ) with further modifications. However, it remained economically unprofitable due to high electricity costs. In contrast, a simpler CCS retrofit became profitable by 2040, reaching an implementation cost of −36 €/t HM by 2050. CO 2 tax and CCS costs were the main economic drivers. The CaL model was implemented in Aspen Plus and validated against experimental and literature data with deviations below 5%.