Experiments and modeling of vapor-liquid equilibrium data in DEEA-CO2-H2O system

New vapor-liquid equilibrium (VLE) experimental data has been collected for DEEA in the concentration ranges of 1-4 M with temperature at 293 K, 313 K, 333 K, and 353 K for CO2 partial pressure in the range from 6.2 kPa to 100.8 kPa. An empirical model has been established based on the experimental data. A comparison of experimental and predicted data gave absolute average relative deviation of 1.72%, 2.68%, 1.32%, and 10.32% for DEEA concentration of 1 M, 2 M, 3 M, and 4 M respectively. Model comparisons have been made using Kent Eisenberg (KE), electrolyte non-random two-liquid (e-NRTL) and UNIQUAC models for the conventional monoethanolamine (MEA)-CO2-H2O system. According to the model comparison results in MEA-CO2-H2O system that KE model suits well with its less property parameters, KE model has been chosen to predict vapor-liquid equilibrium for the DEEA-CO2-H2O system. Both the Henry constant of N2O in DEEA and the equilibrium constant (K-10) for the dissociation of protonated amine reaction were regressed. The absolute average relative deviation (AARD) for ln(K-10) for 1 M, 2 M, 3 M, 4 M DEEA solution were 0.62%, 1.18%, 1.40% and 1.65% respectively indicating excellent agreement. From the model results, KE model suits well when DEEA concentration and temperature is low. The predictions in 1 M and 2 M are acceptable with the absolute average relative deviations of 3.28% and 5.10% respectively. (C) 2016 Elsevier Ltd. All rights reserved.