Field survey of reduced-sulfur emissions from a modern finnish pulp mill

Abstract

Substantial advances in air emission control technology during the last decade have brought about a decrease in reduced-sulfur emissions from pulp mills. Un fortunately, these reduced-sulfur compounds still cause subjective odor problems at very low concentrations. As a result pulp mills, even with efficient odor abatement systems, may produce a foul odor in the surrounding area. On the other hand, it will not be easy to further reduce the malodorous sulfur emissions at modern pulp mills because all the major emission sources have already been eliminated. This paper presents the results of a field survey made at one of the major Finnish pulp mills. In the study, all the main emission sources we re analyzed, and the ambient air concentrations of reduced-sulfur compounds in the area surrounding the mill we re measured. Emission rates from the current sources and measured ambient air concentrations are presented. The effects of the main continuous emission sources on ground level concentrations are estimated by means of a Gaussian model of emission dispersion. In addition, the emission sources are ranked on the basis of the estimated ground level concentrations and the momentary emission rates. Finally, means of reducing the current continuous and occasional emissions of reduced-sulfur are recommended.