Comprehensive mass transfer and reaction kinetics studies of CO2 absorption into aqueous solutions of blended MDEA-MEA

In the present work, the reaction kinetics and mass transfer performance of CO2 absorption into aqueous solutions of blended MDEA-MEA solutions were comprehensively studied. The reaction kinetics was investigated using a laminar jet absorber in terms of a second order reaction rate constant and enhancement factor. The mass transfer performance was evaluated experimentally in a lab-scale absorber packed with high efficiency DX structured packing in terms of CO2 concentration profile and over all mass transfer coefficient (K(G)a(v)). The experiments were conducted over the MDEA/MEA concentrations of 27/3, 25/5, and 23/7 wt% MDEA/wt% MEA (which equivalent to MDEA-MEA molar ratios of 2.3/0.5, 2.1/0.8, and 1.95/1.16 M, respectively). It was found that K-MEA was successfully extracted and can be expressed as: k(MEA) = (5.127 x 10(8)) exp (-3373.8/T). The results also show that the operating parameters (i.e., MDEA-MEA blended ratio, temperature, and CO2 loading) affect both the reaction kinetics and mass transfer performance significantly. Lastly, the MDEA-MEA blended ratio of 1.95/1.16 provided the highest reaction kinetics and mass transfer performance among the three concentrations investigated in this study. (C) 2012 Elsevier B.V. All rights reserved.