Study of oxidation of calcium sulfite in flue gas desulfurization by pore-type surface dielectric barrier discharge

Abstract

Herein, a new pore-type surface dielectric barrier discharge (PSDBD) reactor was first used for the oxidation of calcium sulfite in flue gas desulfurization. The comparison of oxidation efficiency of calcium sulfite using air only oxidation, loop surface dielectric barrier discharge (LSDBD) oxidation, and PSDBD oxidation was carried out to account for the superiority of PSDBD oxidation. The feasibility of calcium sulfite oxidized by discharge plasma was first investigated, and then, the effect of energy density, power frequency, air flow rate, initial slurry concentration, slurry temperature, and slurry pH was explored. The results showed that it was feasible to oxidize calcium sulfite by discharge oxidation as compared to that by air only oxidation. Furthermore, the oxidation efficiency of calcium sulfite in a PSDBD reactor is higher than that in an LSDBD reactor. Higher frequency power, higher energy density, and higher air flow rate were beneficial for the oxidation of calcium sulfite. Higher oxidation efficiency could be obtained at a lower initial slurry concentration, higher slurry temperature, and lower slurry pH, which could reach the highest values of 62.5%, 79.8%, and 73.4% in the PSDBD reactor, respectively. The mechanism analysis illustrated that O₃ played a major role during calcium sulfite oxidation.