Pilot-scale CO₂ capture in a cement plant with CESAR1: Higher stripper pressure reduces energy demand and compression work but increases solvent degradation

Carbon capture from hard-to-abate industries is essential. This study investigates the effect of stripper pressure on the performance of amine-based CO₂ capture from cement flue gas, using the CESAR1 solvent. Through a rigorous data filtering and binning methodology, experimental results were systematically categorized, enabling a precise evaluation of how stripper pressure and stripping intensity affect solvent regeneration, thermal efficiency, and subsequent energy demands. Additionally, a holistic analysis of operating with altered stripper pressure is presented, where downstream compression and solvent degradation are considered. Increasing stripper pressure consistently improves capture efficiency, reduces lean solvent loading, and increases the cyclic capacity, ultimately leading to lower specific reboiler duty. Higher stripper pressure also enhances lean-rich heat exchanger performance by improving temperature differentials. Operating at higher pressure reduces the water load on the overhead condenser, even at elevated temperatures. These conditions, in turn, mitigate overall cooling duties. Elevated stripper pressure decreases both reboiler duty and compression work. From our results, operating at higher pressures does not present downsides. However, degradation rates increase at elevated temperatures. We suggest that the standard operating pressure for capturing CO₂ with the CESAR1 solvent be evaluated, as it provides an opportunity for reduced energy consumption while also monitoring solvent health over extended periods.