Technical Bulletin No. 0078: The State of the Art of Sulfur Dioxide Monitoring in Pulp and Paper Industry Stack Gases (AQTB)

The attached Technical Bulletin provides a state of the art review of possible means for detecting and monitoring sulfur dioxide present in stack gases from various pulping process operations. It was prepared by M. E. Franklin, Research Chemist and 0. A. Fick, formerly Research Chemist at the National Council's West Coast Regional Center, under the direction of A. L. Caron, West Coast Regional Engineer. The bulletin considers (a) those factors of significance in selecting a sulfur dioxide monitor; (b) important elements in the design of the gas sampling system, and (c) the analytical principles that form the basis for the variety of monitors commercially available, as well as their practical features. The bulletin also reviews and stresses the importance of calibration features for such monitoring systems. The bulletin notes that while coulometric titration and electrolytic sensing represent the most commonly employed detector principles, dispersive and correlating spectrometers are finding increased application. Their principal advantage is the possibility of stack monitoring which avoids the need for gas sampling conditioning and delivery systems. It is therefore likely that their usage will increase further.