Experimental Study of CO2 Absorption in Potassium Carbonate Solution Promoted by Triethylenetetramine

Abstract

Background: Separation of CO 2 as the major cause of global warming is essential. In this work, potassium carbonate (K 2 CO 3 ) solution was selected as a base solvent for CO 2 absorption due to its ease of regeneration energy, low cost and low environmental impact. However, the absorption rate of CO 2 with K 2 CO 3 needs to be improved by adding a suitable promoter. Therefore, the performance of CO 2 in K 2 CO 3 solution promoted by triethylenetetramine (TETA) in terms of absorption capacity and absorption rate of CO2 was studied. Method: Experiments were conducted at a total concentration of 2.5 (M) with different TETA mole fractions at temperatures of 303, 313 and 323 K, and CO2 partial pressure up to 30 kPa using a stirred cell reactor. The effect of CO2 partial pressure, temperature and concentration of TETA on absorption capacity and absorption rate of CO2 in K2CO3+TETA solution was discussed in detail. Results: The CO2 loading capacity obtained in this work was compared with monoethanolamine (MEA) and a better performance was observed for K2CO3+TETA solution. In addition, experimental results revealed that the addition of TETA to K2CO3 improved the CO2 reaction rate. Finally, the response surface methodology was employed to correlate the CO2 solubility. It was found that the correlated data are in good agreement with the experiment results. Conclusion: As an overall conclusion, the solution of K2CO3+TETA can be used as a promising absorbent in post combustion CO2 capture processes.