Modeling of pulsed corona discharge process for the removal of nitric oxide and sulfur dioxide

Abstract

A positive pulsed corona discharge process was applied to the removal of sulfur dioxide and nitric oxide from a simulated flue gas stream, and a mathematical model was proposed to describe this process theoretically. The proposed model takes into account generation of radicals by pulsed corona discharge, followed by radical utilization for the removal of the pollutants. Radicals such as O, OH, N, H, etc. may be concerned in the removal of the pollutants. Their concentrations were derived by considering direct electron impact on the dissociation of gaseous molecules (O-2, N-2, H2O) and subsequent excitation transfer reactions of excited oxygen atoms to produce O and OH radicals. The effects of various operating parameters such as feed gas flow rate, initial concentration, oxygen content, humidity, peak voltage and pulse repetition rate on the removal were examined. So as to establish the validity of the model, the calculated results were compared with the experimental data. Although some discrepancy between the calculated and experimental results was observed at high pulse repetition rate, the proposed model was found to properly predict the experimental data on the whole. (C) 2002 Elsevier Science B.V. All rights reserved.