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SULFUR DIOXIDE OXIDATION IN SCRUBBER SYSTEMS
Citation:
Hudson, J. SULFUR DIOXIDE OXIDATION IN SCRUBBER SYSTEMS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/7-80/083 (NTIS PB80187842), 1980.
Description:
The report relates the liquid-phase oxidation kinetics of bisulfite and sulfite anions (determined in bench scale experiments) to conditions representative of limestone scrubbers used for flue gas desulfurization. The chemical reaction rates were determined for clear solutions and slurries of calcium sulfite when gas-to-liquid transfer of oxygen was not a limiting resistance. From the experimental results, a mathematical model was developed for the overall oxidation rate of calcium sulfite slurries, including solids dissolution and chemical reaction. The overall rate is shown to decline with increasing pH due to the reduced solubility of calcium sulfite; the solid dissolution rate is thus the limiting factor at high pH. The homogeneous chemical oxidation rate is 1.5 order and increases with pH. Organic acids inhibit the oxidation reaction, especially glyolic acid. Manganese and iron catalyze the oxidation reaction even in the presence of organic inhibitors.