Nox-Emission Characteristics for Lime Kilns in the Pulp Industry, 1993 Environmental Conference Proceedings

The emissions of nitrogen oxides (NOx) from three lime kilns in the Swedish pulp industry have been studied with respect to different fuels (external and internal fuels from the pulping process). Correlations between fuel type and NO, emissions have been found which reflect the nitrogen contents of the fuels. In addition the correlation between NOx emission and combustion temperature was observed.

The results indicate that significant reductions in NOx emissions from lime kilns may be achieved by withdrawing from incineration of non-condensable gases and their derivatives. The viability of this in practice however, depends on an appropriate alternative disposal of the non-condensable gases. In one of the kilns studied, virtually no fuel dependence on the NO, emissions was seen and only a strong temperature correlation existed. Consequently, the appropriate measures to reduce NOx emissions are likely to be specific for a given lime kiln.