Aqueous absorption of nitric oxide induced by sodium chlorite oxidation in the presence of sulfur dioxide

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 tl;ere 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/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 for a spray chamber scrubber and height of transfer unit for a packed bed scrubber.