The influence of reaction conditions on SO/sub 2/ oxidation in a discharge plasma reactor

In this paper, experimental approaches have been carried out to investigate the removal of sulfur dioxide (SO/sub 2/) using pulsed discharge nonthermal plasma in the absence of ammonia (NH/sub 3/). The gas-phase reaction was found to be less attractive due to its large energy cost. The increase in temperature decreased the SO/sub 2/ removal rate, resulting in large energy cost. SO/sub 2/ removal was increased as the concentration of water vapor increased. The presence of SO/sub 2/ did not influence the gas-phase removal of NO in an NO-SO/sub 2/-O/sub 2/-H/sub 2/O-N/sub 2/ system. In the case of the wet-type plasma reactor, gas-phase discharge plasma directed to the surface of water film greatly enhanced the liquid-phase oxidation of HSO/sub 3//sup -/ to SO/sub 4//sup 2-/. Comparing the results with different absorbents indicated that the hydroxyl (OH) radical plays a key role in the plasma induced liquid-phase reactions.