CO2 Solubility in Electrolyte Solution of Potassium Carbonate with the Addition of Promotor Amines (MDEA-DEA/ PZ-DEA) at Various Temperatures

Abstract

Carbon dioxide has a huge impact on the increase of greenhouse gas formation causing global warming and climate change. The most effective method to capture CO 2 is chemical absorption using potassium carbonate (K 2 CO 3 ) solution and amines as additive to enhance the absorption rate. CO 2 solubilities in 30% of K 2 CO 3 and 5% of the total composition of mixed methyldiethanolamine (MDEA)–diethanolamine (DEA) / piperazine (PZ)-DEA solutions at various temperatures of 303.15-323.15 K and atmospheric pressure are reported. The solubility data were measured using an equilibrium cell apparatus with the N 2 O analogy method. The E-NRTL model was used to correlate the experimental data accurately. The binary interaction parameters of the model for the CO 2 -K 2 CO 3 -MDEA-DEA-H 2 O and CO 2 -K 2 CO 3 -PZ-DEA-H 2 O systems were obtained. The CO 2 physical solubility in 30% of K 2 CO 3 , 5% of PZ, and 0% of DEA at 303.15 K had the highest value, while the Henry constant of CO 2 in this solution had the lowest value. The CO 2 loading increased with increasing partial pressure of CO 2 , while the CO 2 solubility decreased with increasing temperature. Any increase in MDEA concentration from 0% to 5% enhanced the CO 2 partial pressure, otherwise, an increase in PZ concentration from 0% to 5% decreased the CO 2 partial pressure.