Technical Bulletin No. 0097: A Study of the Use of Bag Sampling in Determining TRS Emission from Kraft Pulping Sources (AQTB)

Despite the extensive application of continuous reduced sulfur monitoring at lime kilns and kraft recovery furnaces there remains a need for intermittent measurements of reduced sulfur at these and other sources in the kraft industry. The installation and operation of appropriate sampling and analytical instruments at each source is time consuming. In addition, the non-combustion sources have been demonstrated to be sufficiently uniform in emission rate for adequate characterization using grab or short-term composite samples. One procedure used for collection and transfer of these grab or short-term composite samples is an inert bag manufactured from Teflon. The attached technical bulletin describes a study carried out to determine the utility of bag collected samples at several sources in the kraft industry.  The study showed that the rate of reduced sulfur decay and composition in samples from recovery furnaces and lime kilns was rapid and variable when samples are collected in a bag for subsequent analysis. They are therefore not suitable for gas chromatographic analysis and only for a non-specific sulfur analysis if sulfur dioxide is removed at the time of sample collection and the analysis is started within ten minutes. The collection and storage of samples from non-combustion sources from subsequent analysis was found to be satisfactory if analysis for total reduced sulfur (TRS) was started soon after sample collection. The stability of individual TRS compounds in the sample container was not determined. The findings of this study should be pertinent to those mills interested in the analysis of TRS from non-combustion sources