Influence of pKa on solvent performance of MAPA promoted tertiary amines

The results indicated that the optimal pKa of the tertiary amines, giving the highest absorption capacity and cyclic capacity, was in the range of 9.48-10.13. At a higher pKa value, the cyclic capacity was decreased. Further, addition of MAPA to the tertiary amines influenced the absorption performance by increasing the absorption capacity for tertiary amines with low pKa (7.79-9.03) and decreasing the absorption capacity for tertiary amines with high pKa (9.48-10.42). Also, the CO2 absorption rate was significant enhanced by addition of MAPA.