Role of Thiosulfate in NO₂ Absorption in Aqueous Sulfite Solutions

NOx emissions continues to be a major challenge in order reduce the environmental impact of thermal conversion non-recyclable waste and fuels with high nitrogen contents. Oxidation NO NO2 followed by absorption aqueous solutions sulfur compounds as additives has recently gained more attention from flue gases. One is consumption sulfite, requiring sulfite oxidation inhibitors such thiosulfate. The present study clarifies chemistry thiosulfate wet scrubbing buffered under well-controlled conditions at neutral pH 25 °C. Absorption rates for reaction scrubber were determined, ability inhibit was investigated quantified. With 1 mM (no sulfite) solution, rate increased 30% compared pure water 160% 100 time presence oxygen. thiosulfate), initial 200% water. However, decreases significantly after short periods due through undesired O2. In tests an inhibitor, removal efficiencies could maintained over extended time. 10 decreased 130 31 mg·L–1·min–1, 2 16 mg·L–1·min–1. For conditions, did not change when higher concentrations used. results demonstrate low pH.