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CHLORINE ABSORPTION IN S(IV) SOLUTIONS
Citation:
Roy, S. AND G. T. Rochelle. CHLORINE ABSORPTION IN S(IV) SOLUTIONS. U.S. Environmental Protection Agency, Washington, DC, EPA-600/R-01/054 (NTIS PB2001-107826), 2001.
Impact/Purpose:
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Description:
The report gives results of measurements of the rate of Chlorine (Cl2) absorption into aqueous sulfite/bisulfite -- S(IV) -- solutions at ambient temperature using a highly characterized stirred-cell reactor. The reactor media were 0 to 10 mM S(IV) with pHs of 3.5-8.5. Experiments were performed using 20-300 ppm Cl2 in nitrogen or air. Cl2 absorption was modeled using the theory of mass transfer with chemical reaction. Cl2 reacts quickly with S(IV) to form chlorine and sulfate. Cl2 absorption is enhanced by increasing pH and S(IV) concentration. The rate constant for the reaction of Cl2 with S(IV) was too rapid to be precisely measured using the existing stirred-cell reactor, due to mass transfer limitations. However, the most probable value of the rate constant was determined to be 2 x 10 to the 9th power L/mol-s. These results are relevant to the simultaneous removal of Cl2, sulfur dioxide, and elemental mercury (Hg) from flue gas. The developed model shows that good removal of both Cl2 and Hg should be possible with the injection of 1-10 ppm Cl2 to an existing limestone slurry scrubber. These results may also be applicable to scrubber design for removal of Cl2 in the pulp and paper and other industries.