Equilibrium Solubility Measurement and Modeling of CO<sub>2</sub> Absorption in Aqueous Blend of 2-(Diethyl amino) Ethanol and Ethylenediamine
Shailesh Kumar, Ritesh Padhan, Monoj Kumar Mondal
Abstract
The equilibrium CO 2 solubility in an aqueous blend of 2-(diethyl amino) ethanol (DEEA) and ethylenediamine (EDA) was performed at atmospheric pressure with the use of a laboratory scale bubbling absorber. The total concentration of amine blend solution in the range of 1.13–4.90 mol·kg –1 and the EDA mole fraction in the total amine blend in the range of 0.05–0.20 were taken. The experiments for the measurement of CO 2 solubility were performed at a temperature range of 303.15–333.15 K and CO 2 partial pressure range of 10.13–20.27 kPa. The analysis of CO 2 in the liquid phase was accomplished by a direct titration method using HCl solution. The solubility data of CO 2 in DEEA+EDA solution of the present study were compared with data available in the literature. The experimental results were applied to develop an empirical mathematical model with an average absolute deviation of 7.03% to predict the CO 2 equilibrium solubility in DEEA+EDA solution within the specified range of operating conditions. In addition, the heat of absorption of CO 2 in the DEEA+EDA solution was estimated by using the Gibbs–Helmholtz equation, and it was found to be −70.50 kJ mol –1 lower than that of the benchmark amine MEA.