The influence of reaction conditions on SO2 oxidation in a discharge plasma reactor

In this paper, experimental approaches have been carried out to investigate the removal of sulfur dioxide (SO2) using pulsed discharge nonthermal plas ma in the absence of ammonia (NH3), The gas-phase reaction was found to be less attractive due to its large energy cost. The increase in temperature d ecreased the SO2 removal rate, resulting in large energy cost. SO2 removal was increased as the concentration of water vapor increased. The presence o f SO2 did not influence the gas-phase removal of NO in an NO-SO2-O-2-H2O-N- 2 system. In the case of the wet-type plasma reactor, gas-phase discharge p lasma directed to the surface of water film greatly enhanced the liquid-pha se oxidation of HSO3- to SO42-. Comparing the results with different absorb ents indicated that the hydroxyl (OH) radical plays a key role in the plasm a induced liquid-phase reactions.