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

Abstract

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 (KGav). The experiments were conducted over the MDEA/MEA concentrations of 27/3, 25/5, and 23/7wt% MDEA/wt% MEA (which equivalent to MDEA–MEA molar ratios of 2.3/0.5, 2.1/0.8, and 1.95/1.16M, respectively). It was found that kMEA was successfully extracted and can be expressed as: kMEA=(5.127×108)exp-3373.8T. 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.