Aqueous Absorption of Nitric Oxide Induced by Sodium Chlorite Oxidation in the Presence of Sulfur Dioxide

Abstract

The absorption of NO from a gas stream containing SO2 by aqueous solution Of NaClO2 was studied in a bench scale scrubber. NOx removal of up to 95% was obtained using a packed bed scrubber. The corresponding SO2 removals were 100%. Experiments were also conducted in a bubble column and a spray chamber scrubber in order to obtain engineering data for scale-up and process design. A novel UV/Vis photodiode array (PDA) method was developed for real-time monitoring of oxychlorine compounds in the scrubbing solutions. As a consequence of the data obtained with the PDA system, a much better understanding of the chemistry of the scrubbing system has led to a simpler mass transfer model than is available in the literature. Absorption rates are reported in terms of overall reaction rates fora spray chamber scrubber and height of transfer units for a packed bed scrubber.