An overview of the formation of SO/sub x/ and NO/sub x/ in various pyroprocessing systems

Abstract

The authors identify SO/sub 2/ and NO/sub x/ emission levels of various kiln systems and explain the reasons for the variations ascertained. Various recent methods of reducing SO/sub 2/ and NO/sub x/ emission from cement kiln systems are outlined. SO/sub 2/ emission monitoring and regulations are outlined briefly and a comparison is made of SO/sub 2/ emissions from various kiln types. The kilns discussed include: wet-process kilns, long dry-process kilns, preheater kilns, and precalciner kilns. Methods for reducing SO/sub 2/ emissions are discussed. The formation of nitrogen oxide in kilns is also discussed. Finally, techniques for reducing NO/sub x/ emissions are examined.<>