Removal of SO2 from gas streams using a dielectric barrier discharge and combined plasma photolysis

The removal of SO2 from simulated gas streams (N2/O2/H2O/SO2) is experimentally investigated using a dielectric barrier discharge, and by computer modeling. Conversion of SO2 to primarily H2SO4 is found to be limited by the generation of OH radicals. Increasing the concentrations of O2 and H2O increases the generation of OH radicals and results in more removal of SO2 from gas streams. Removal efficiencies of ≳80% were experimentally achieved. Results from the model suggest that more efficient removal is obtained with a series of short, high E/N current pulses rather than a single, low E/N current pulse. Results from the model also suggest that uv illumination of the plasma to photolyze O3 will improve the removal of SO2 from the gas stream. Photolysis of O3 produces O(1D) atoms which generate OH radicals by H abstraction from H2O, thereby increasing the removal of SO2.