Development of a facile reclaiming process for degraded alkanolamine and glycol solvents used for CO2 capture systems

Abstract

Post-combustion CO2 capture based on alkanolamine solvents is currently the most developed and ready-to-use technology to reduce CO2 emission into the atmosphere. The CO2 gas captured by this method usually displays a moderate level of moisture, which requires dehydration through the use of glycol solvents. However, due to exposure to impurities in the flue gas stream and high temperatures, these solvents can experience chemical and thermal degradation. The build-up of degradation products can lead to plant operational problems and increase consumption of utilities such as gas and electricity.A new reclaiming process was therefore developed to separate degradation products and other types of impurities from these solvents. A detailed analysis of the feed stream, the recovered product stream, and the waste stream showed that this novel reclamation technology is capable of removing most of the undesirable impurities and degradation products and restoring the solvent to almost its original purity at a high recovery rate with minimal energy consumption. The data generated by this study will be useful for scaling-up and designing commercial reclaimers that can meet the solvents’ cleanup targets with low expenditure, low energy consumption, and minimal waste for disposal.