Removal of SO2 from Flue Gas by Sodium Humate Solution

Abstract

A novel process of flue gas desulfurization (FGD) by sodium humate (HA−Na) solution was developed. Experiments were carried out to examine the effect of various operating parameters, such as the HA−Na concentration, pH, temperature, gas flow rate, O2 concentration, SO2 inlet concentration, and NO2, on the SO2 absorption efficiency and desulfurization time in a lab-scale bubbling reactor. The experimental results indicate that the HA−Na concentration significantly influences the desulfurization time but has little effect on the SO2 absorption efficiency. The desulfurization time increases with the HA−Na concentration reaching 0.06 g/mL, and after this value, it begins to decrease. The SO2 absorption efficiency maintains 99% when pH is above 4.5. A low gas flow rate and low temperature are favorable to SO2 absorption. The increase of the SO2 inlet concentration improves the mass transfer of SO2 and accelerates the SO2 consumption rate. NO2 coexisting with SO2 can promote SO2 absorption because it may speed ...