Investigation on the inclusion of 1-(2-aminoethyl) piperazine as a promoter on the equilibrium CO2 solubility of aqueous 2-amino-2-methyl-1-propanol

Abstract

The present work demonstrates the experimental and theoretical study of equilibrium CO2 solubility in a potential absorbent, aqueous 1-(2-aminoethyl) piperazine (AEP) and its blend with 2-amino-2-methyl-2-propanol (AMP). The measurements have been conducted at 303.2 to 323.2 K and within the CO2 partial pressure range of 2 to 250 kPa. The experimental data are modeled using modified Kent-Eisenberg (KE) equilibrium model for all the concentration range. Carbamate hydrolysis and AEP deprotonation constants are expressed as a function of pressure, temperature and amine concentration from the modified KE model. The developed model is used to predict the equilibrium liquid phase speciation in the CO2 loaded amine solution. An artificial neural network (ANN) model is also developed to predict the CO2 solubility in the understudy solvent system. The feed forward ANN model provides very good prediction with respect to the experimental solubility data having an average absolute deviation (% AAD) of 0.16. Qualitative 13C NMR and FTIR-ATR analysis have been performed for CO2 loaded solvent to understand the reaction scheme and identify the various important reaction products. Further, physicochemical properties such as density and viscosity of both the binary and ternary solvent system were also determined and correlated using Redlich-Kister and Grunberg-Nissan models.