Cement Kiln NOx Reduction Experience Using the NOxOUT(r) Process.pdfVIP

Proceedings of IJPGC2000: 2000 International Joint Power Generation Conference July 23-26, 2000, Miami Beach, Florida CEMENT KILN NOx REDUCTION EXPERIENCE USING THE NOxOUT? PROCESS M. Linda Lin, Fuel Tech, Inc. Michael J. Knenlein, Fuel Tech, Inc. KEY WORDS: NOx, Cement, Kiln, Air Pollution A B S T R A C T Urea-based Selective Non-Catalytic Reduction (SNCR) is a proven NOx control technology for many types of combustion systems. Cement kilns pose special challenges for the control of NOx emissions. The wide variety of mechanical designs, the process requirement for high combustion temperatures, diverse and changing fuels, NOx generation from multiple locations, and the variability of the NOx emission rates add to the complexity of the challenge. There have been a number of demonstrations and commercial systems installed for NOx control using a Urea-SNCR process called NOxOUT?. The Urea-SNCR experience in kiln combustion devices includes various designs of long moving-grate kilns, long wet kilns, preheater, and preheater/precalciner kilns for cement production, and coke calcining kilns for petroleum processing. Valuable SNCR design and operation information has been obtained that allows NOx reduction in a cost-effective way, while maintaining efficient cement production. This paper summarizes our NOx reduction experiences in kiln systems. Specific SNCR performance and the economics associated with two preheater/precalciner types of cement production systems are described. INTRODUCTION Fuel Tech, Inc. (FTI) has successfully commissioned over 250 commercial contracts that reduce NOx emissions from stationary sources in many parts of the world. FTI NOx control technologies have been primarily implemented using a Urea-based Selective Non-Catalytic Reduction (SNCR), called the NOxOUT? Process. While the SNCR experience in the cement industry has been relatively limited, FTI has conducted over ten (10) demonstrations in various type