Sulfite oxidation in seawater flue gas desulfurization by plate falling film corona-streamer discharge

• Tried to use plate falling film discharge to solve the scale-up problem of electric discharge reactor.
• Preliminarily discussed the mechanism of sulfite oxidation by electrical discharge.
• Found that the discharge power density is the dominating factor of sulfite oxidation rate.
• Simplified the kinetic model in terms of sulfite concentration and power density.

In this paper, sulfite containing effluent from the packed tower of seawater flue gas desulfurization is treated by plate falling film corona-streamer discharge which can solve the scale-up problem of electrical discharge reactors. Effects of pH, electrical discharge intensity, effluent flow rate and temperature on sulfite oxidation are considered. Experimental results indicate that discharge power density is the dominating factor which affects the sulfite oxidation rate by affecting the gaseous radical concentration. Based on experimental results, sulfite oxidation by corona-streamer discharge is proposed as the combination of chain reaction path and radical self-reaction path. In addition, the simplified kinetic equation is expressed in terms of sulfite concentration and discharge power density. Comparing with cylindrical falling film corona-streamer discharge, the plate falling film corona-streamer discharge leads to a fold increase in energy efficiency, besides, scale-up of a plate falling film corona-streamer discharge reactor will affect the energy efficiency insignificantly, all these indicate that the plate falling film discharge has a better potential in large scale utilization than cylindrical falling film discharge.