Effect of heat stable salt bis-(2-hydroxyethyl) methylammonium formate on CO2 absorption in aqueous methyldiethanolamine solution

Abstract

In this work, the solubility of CO2 in aqueous methyldiethanolamine (MDEA) + bis-(2-hydroxyethyl) methylammonium formate (BHEMAF) system was measured using the static method at two temperatures (298.15 and 313.15 K) in the pressure range of 100–2100 kPa. Two sets of experiments were performed. In the first set, the weight percentage of BHEMAF, MDEA and H2O in H2O + MDEA + BHEMAF solutions were 7.5–10 wt%, 15–39.38 wt% and 53.12–75 wt%, respectively. In the second set of experiments concentration of BHEMAF was set as 0.3 and 0.6 M in the aqueous solutions of 25 wt% MDEA. Experimental data showed that the solubility of CO2 in the H2O + MDEA + BHEMAF solutions decreases with increasing BHEMAF concentration. The Deshmukh-Mather thermodynamic model was then used to calculate the solubility of CO2 in H2O + MDEA + BHEMAF solutions. The binary interaction parameters of the model were adjusted by regression to experimental data. The modeling results showed that the average absolute relative percent deviation for all the data points was 7.87%.