[Wet FGD process on rotating-stream-tray tower with magnesium-enhanced lime]

Wet flue gas desulfurization(FGD) process with magnesium-enhanced lime slurry was conducted on a rotating-stream-tray tower. Changes of SO2 removal efficiency and slurry pH with time were experimentally determined. Effects of magnesium sulfate concentration were investigated and the lime utilization was calculated according to experimental data. In comparison with lime FGD process, adding magnesium sulfate could effectively enhance SO2 removal efficiency; when the adequate magnesium sulfate concentration was 0.2 mol/L, the removal efficiency was more than 60% with two rotating-stream-trays, while the removal efficiency of lime process was only 45%. To achieve higher SO2 removal efficiency, the slurry pH should be controlled between 6.0 and 7.5. Magnesium sulfate could also promote lime dissolution, slow down descent of slurry pH and increase lime utilization; when magnesium sulfate concentration was 0.2 mol/L, lime utilization could be increased by more than 5 percentage point under adequate conditions.