(194b) Operating Flexibility and Controllability of CO2 Post-Combustion Capture Process with Different Amines

Carbon dioxide (CO₂) emissions capture from post-combustion is a key aspect in the stabilization of global climate change. Post-combustion CO₂ capture using amine-based solvents, typically monoethanolamine (MEA) and (Methyl diethanolamine) MDEA, is one of the most promising technologies for the CO2 emissions reduction. In practice, because power plants need to adjust their operation loads according to the peak and off-peak scenarios of power consumptions, the feed rate of flue gas from power plants features significant fluctuations. Thus, a CO₂ capture process has to consider its operating flexibility and controllability issues under disturbance of feed rate changes. In this study, a dynamic model of CO₂ capture process has been developed to study dynamic behaviors of the CO₂ capture process with different solvents (MEA or MDEA). Such a dynamic study is a must because MEA and MDEA have different CO₂ absorption capacities and reaction rates with CO₂, which will lead to different controllability of the process. In our study, the flue gas flow rate and reboiler heat duty are key process variables that determine the lean loading, liquid to gas ratio and percentage of CO₂ removal. The results show that the lean loading stream entering the absorber unit is critical to maintain the feasible operation of the system. Moreover, the energy performance of the process is directly affected by the operation of the reboiler. The outcomes from this study may provide more insights into the CO₂ capture process regarding the dynamic behavior of this process, which can be useful to help choose optimal amines for the specific process.