Potential of different additives to improve performance of potassium carbonate for CO2 absorption

Abstract

The performance of potassium carbonate (K2CO3) solution promoted by three amines, potassium alaninate (K-Ala), potassium serinate (K-Ser) and aminoethylethanolamine (AEEA), in terms of heat of absorption, absorption capacity and rate was studied experimentally. The experiments were performed using a batch reactor, and the results were compared to pure monoethanolamine (MEA) and K2CO3 solutions. The heat of absorption of K2CO3+additive solution was calculated using the Gibbs-Helmholtz equation. In addition, a correlation for prediction of CO2 loading was presented. The results indicated that absorption heat, absorption rate and loading capacity of CO2 increase as the concentration of additive increases. The blend solutions have higher CO2 loading capacity and absorption rate when compared to pure K2CO3. The heat of CO2 absorption for K2CO3+additive solutions was found to be lower than that of the pure MEA. Among the additives, AEEA showed the highest CO2 absorption capacity and absorption rate with K2CO3. In conclusion, the K2CO3+AEEA solution with high absorption performance can be a potential solvent to replace the existing amines for CO2 absorption.