Pilot-Scale CO2 capture in a cement plant with CESAR1: Emission control with acid wash and absorber intercooling

This work investigates how to reduce emissions from degradation byproducts. A pilot scale unit is used to capture CO 2 from cement flue gas, using a AMP/PZ solvent blend, commonly known as the CESAR1 solvent. To reduce emissions, we implemented a wash tower. The wash tower was operated both with a single and double bed water wash and with an acid wash. Another emission control strategy was operating the capture process with intercooling on the absorber column. We used ammonia emissions as a key indicator of solvent degradation. When implementing a wash tower, equipped with an acid wash section, a 92.4% reduction in amine degradation byproducts in the gas could be achieved. Several compounds reached non-detectable levels, indicating a substantial decrease in degradation products escaping the system. Introducing a double water wash bed reduced ammonia levels but was insufficient to remove it altogether, highlighting the temperature dependency of ammonia solubility and the limited effectiveness of water in thermally driven systems. Additionally, the study revealed that absorber intercooling effectively minimized degradation byproducts by controlling the solvent temperature, significantly influencing the amount of degradation products emitted. These findings suggest that integrating acid washing with intercooling can significantly improve amine-based carbon capture systems’ efficiency, durability, and environmental performance.