A Study on the Degradation Performance of MDEA/PZ and MDEA/AEP With the Influence of Sulfur Compounds

With the increasing global energy demand and its environmental impacts, carbon capture, utilization, and storage technology (CCUS) has become a crucial means to reduce CO 2 emissions and address climate change. This study investigated the thermal and oxidative degradation characteristics of two amine blend absorbents, methyldiethanolamine (MDEA)/piperazine (PZ) and MDEA/2-(piperazin-1-yl) ethanamine (AEP) and explored the effect of sulfur compounds on their stability. The experimental results indicated that MDEA/PZ exhibited a lower thermal degradation rate, whereas MDEA/AEP, due to the thermal instability of the AEP component, showed poorer degradation performance. In terms of oxidative degradation, monoethanolamine (MEA) demonstrated a higher oxidative degradation rate, whereas MDEA/PZ and MDEA/AEP exhibited lower oxidative degradation rates. The addition of inhibitors reduced the oxidative degradation rates of MDEA/PZ and MDEA/AEP, with antimony potassium tartrate (APT) proving to be the most effective inhibitor. In sulfur-containing environments, sulfur compounds (hydrogen sulfide and carbonyl sulfide) significantly enhanced both the thermal and oxidative degradation rate of MDEA/PZ and MDEA/AEP, particularly for MDEA/AEP, where the thermal degradation rate increased by 25.2%. This study revealed the impact of sulfur compounds on the thermal and oxidative degradation of absorbents. The findings provide important experimental data and theoretical support for optimizing the stability of carbon capture absorbents.