Reduction of Total Reduced Sulphur (TRS) from Kraft Mill Emission Vents Using Residual Bleach Plant Chlorine Dioxide, 1999 Environmental Conference Proceedings

Brian O’Connor

Paprican

Dominique Phaneuf & Terry Dunn

Domtar Papers

A simple and cost effective approach to reduce odorous miscellaneous total reduced sulphur (TRS) sources at a kraft mill was identified. The approach involved mixing the TRS gas stream with the waste residual chlorine dioxide that is present in the unscrubbed bleach plant stack gas. Since chlorine dioxide is a strong chemical oxidant it is capable of quickly reacting with the TRS components typically found in kraft pulp and paper mills. The source of TRS studied at this mill was the weak black liquor storage tank, a high-volume-low-concentration (HVLC) source, which typically emits TRS at concentrations of 100-200 ppmv. In a small pilot trial at the mill, mixing simulated weak black liquor tank emissions (TRS levels of 245 and 426 ppmv) with the unscrubbed bleach plant stack gas (emitting 2-6 kg ClO /h) was 2 found to effectively remove the TRS components that were present.