CO2 quality control through scrubbing in oxy-fuel combustion: An evaluation of operational pH impacts, and prediction of SO2 absorption rate at steady state

The absorption rates of SO2 obtained in the steady state experiments were predicted by a model based on the instantaneous reaction assumption. This model generally overestimates the absorption rates of SO2 at pH values below 6 indicating a kinetic limitation of SO2 and water reaction at low pH values. The analysis on the controlling regions indicates that the gas side mass transfer resistance decreases with the concentration of SO2. Liquid side resistance becomes more important at a lower pH and a higher concentration of SO2.