Sulfite oxidation in seawater flue gas desulfurization by a pulsed corona discharge process

Abstract

For seawater flue gas desulfurization (SWFGD), oxidation of S(IV) to S(VI) in the effluent of the gas desulfurization (FGD) system is very critical for its industrial application, because the additional S(IV) results in high chemical oxygen demand (COD) value. This paper reports a novel pulsed corona discharge oxidation process to convert S(IV) to S(VI) by use of a cylindrical wetted-wall pulsed high voltage reactor. Several important parameters, including pH values, flow rate of the solution, voltage, electrode radius and the length of the plasma region, were investigated for S(IV) oxidation and energy efficiency (G) of the process. After discharge for 12 min, with the electrode radius of 8 mm, pH value of 3, flow rate of 40 L h −1, more than 95% of S(IV) was oxidized and the energy efficiency was about 5.8 × 10 −9 mol J −1. Compared with the traditional air oxidation process, the plasma-induced oxidation is a promising and attractive technology for the SWFGD system.