Solvent Degradation and Emissions from a 0.7MWe Pilot CO₂ Capture System with Two-stage Stripping

The UKy-CAER team successfully tested an advanced 0.7 MWe post-combustion CO₂ capture system on a coal-fired power plant using a heat integration process combined with two-stage stripping to enhance the CO₂ absorber performance. One of the unique feature of the UKy-CAER integrated process is a two-stage stripping unit for solvent regeneration. The secondary stripper is empowered by the heat rejection from a conventional steam-heated (primary) stripper. The secondary stripper outlet stream at the commercial scale can be used as boiler secondary combustion air, consequently enriching the flue gas with CO₂, resulting in less energy penalty required by the CO₂ capture system. The primary goal of this study was to form an initial assessment of the impact on the amine solvent from coal combustion flue gas contaminants and the potential higher oxygen content in the solvent due to incorporation of the secondary air stripper into the conventional amine scrubber/stripper system. The overall oxidative degradation was comparable to previous reports with 30 wt% MEA solvent at similar flue gas run hours. This suggests that the addition of the secondary air stripper appears to be negligible with regards to solvent oxidation. Published by Elsevier Ltd.