Experiments and Modeling of Vapor-liquid Equilibrium in DEEA-CO2-H2O System

Abstract

New vapor-liquid equilibrium (VLE) experimental data has been collected for DEEA in the concentration range of 1 to 4M at temperatures of 293K, 313K, 333K, and 353K for CO2 partial pressure in the range from 6.2kPa-100.8kPa. An empirical model has been established based on the experimental data. A comparison of experimental and predicted data gave absolute average deviation of 1.72%, 2.68%, 1.32%, and 10.32% for DEEA concentration of 1M, 2M, 3M, and 4M respectively. The Kent-Eisenberg (KE) model was chosen to predict vapor-liquid equilibrium for the DEEA-CO2-H2O system. Both the Henry's constant for N2O in aqueous DEEA and the equilibrium constant (K10) for the dissociation of protonated amine were regressed. The absolute average deviations (AAD) for ln(K10) for 1M, 2M, 3M, and 4M DEEA solution were 0.62%, 1.18%, 1.40% and 1.65% respectively, indicating excellent agreement. From these results, the KE model is well suited when DEEA concentration and temperature are low. The predictions in 1M and 2M are acceptable with the absolute average deviations of 3.28% and 5.10% respectively.