Kinetic study of carbon dioxide absorption by aqueous solutions of N-methyldiethanolamine and piperazine

摘要

The kinetics of CO absorption with aqueous blends of N-MethylDiEthanolAmine (MDEA) and PiperaZine (PZ) has been widely studied (Zhang et al., 2001, Bishnoi and Rochelle, 2002, Edali et al., 2010, Samanta and Bandyopadhyay, 2011). Nevertheless, some discrepancies remain concerning the reaction mechanisms proposed in the literature. For instance, the synergy between both amines is still not completely understood and proposed kinetics models cannot fully explain the experimental data at very high loadings. Moreover, the models used in the literature to deduce the kinetics of CO absorption by aqueous blends of PZ and MDEA from experiments present some limitations. They all assume a constant CO partial pressure in the gas phase. This hypothesis can lead to noticeable deviations if high CO quantities are absorbed. The objective of this work is to investigate the kinetics of CO absorption by aqueous blends of MDEA and PZ. Experiments are performed in a wetted wall column (WWC) under various operating conditions and simulated using a rigorous reactor model.