DISPLACE post-combustion carbon capture technology - Integration in a steel plant for mitigation of CO2 emissions

The decarbonization of the steel industry, responsible for approximately 7% of global direct energy-related CO2 emissions, is pivotal in advancing toward a more sustainable future. Carbon capture technologies play a crucial role in achieving this objective. This study presents the description, modelling, and characterization of the DISPLACE carbon capture technology, an isothermal and isobaric adsorption technology using with concentration swing regeneration. The process yields a high-purity CO2 stream alongside a CO2-lean gas stream and its application to the decarbonization of flue gas from oxy-fired hot-stoves in a BF-BOF steel mill is described. Various DISPLACE operating conditions were simulated reaching performances of carbon capture ratios up to 98% and (dry) carbon purities up to 99%. Environmental and economic Key Performance Indicators (KPIs) were assessed, demonstrating the advantage of operating at 400 degrees C due to the reduced DISPLACE steam-to-carbon ratio. The production of steam for adsorbent regeneration requires additional fuel such as NG or coke oven gas (COG). When operating DISPLACE at optimal conditions and considering COG as fuel, a carbon avoidance greater than 78% can be reached with a SPECCA and a CCA equal to 3.65 GJ/t(CO2) and 91.89 (sic)/t(CO2) respectively, values significantly lower than competitive MEA technology (SPECCA equal to 4.86 GJ/t(CO2) and CCA of 113.33 (sic)/t(CO2)). Additionally, the impact of varying DISPLACE carbon capture ratios (CCR) and carbon purity was evaluated.