Parametric analysis using AMP and MEA as aqueous solvents for CO2 absorption

Abstract

Chemical absorption (or reactive absorption) is a common technique used for gas sweetening purposes, capturing acid components from point source emissions or even from ambient air (Cheng and Tan, 2011). CO2 reactive absorption is extensively studied as it is a very effective process, targeting to the emissions reduction of this dangerous greenhouse gas, with wide perspective for further optimization. Reactive absorption combines physical absorption and reaction between acid components and basic solvents, thus the modelling of these mechanisms is challenging and requires a multi-component design (Koronaki et al., 2013).In this work, a rate-based, steady state model, based on the two-film theory, is presented and it is validated for two alkanolamine based aqueous solvents, Mono-ethanolamine (MEA) and 2-Amino-2-methyl-1-propanol (AMP). The model predictions are validated against data extracted by experiments conducted in a pilot scale absorption column with random packing. The comparisons between the model results and the experimental data reveal satisfactory predictions of the various parameters’ profiles along the column.A parametric analysis is performed, investigating the effect of inlet gas and liquid flow rates, the initial liquid loading, the type of packing, the initial amine solution concentration and the gas and liquid inlet temperatures on the CO2 absorption efficiency and on the temperature of the liquid getting out the column. The sensitivity analysis shows that the gas flow rate entering the column is the most important factor influencing the CO2 removal efficiency. In addition, inlet liquid temperature has the greater statistical significance on the outlet liquid temperature. The comparison of the two solvents under the same reference conditions shows that MEA is more efficient as solvent for CO2 absorption.