Technical Bulletin No. 0804: Laboratory Studies of In-digester Black Liquor Oxidation for TRS Destruction

This report presents the results of a laboratory investigation of in-digester black liquor oxidation (IDO) for the oxidation of TRS compounds from kraft pulping. Kraft cooks of Douglas fir chips to both low (28 to 29) and high (95 to 96) kappa with and without introduction of oxygen at the completion of the cook were carried out in 10 liter batch digesters. The results indicate that all of the hydrogen sulfide, methyl mercaptan, and dimethyl disulfide species were converted to nonvolatile compounds by the IDO treatment in about 4 to 7 min.