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Show 3--<a> NOx Emissions From a Commercial Hazardous Waste Incinerator John Veranth, Principal Engineer Aptus, Aragonite, Utah ~ j.J \-> Ofe.'rJ~> f'~ Abstract Zr'~/ Is"l. s<Y v t" ~) ~ b'Y ty.6oD '9 The NOx emissions observed during the startup period of a commercial hazardous waste rotary kiln incinerator showed poor correlation between NOx levels and either' combustion temperature or excess air. High levels of chlorine in the waste streams correlated with low NOx emissions. The highest NOx emissions 1 \ occured when the plant was offwaste and burning fuel oil only. Introduction Aptus operates two commercial rotary kiln hazardous waste incinerators. The plants were designed by Ford, Bacon & Davis and are based on technology from Deutsche-Babcock and from BASF. The design of the Utah facility will be described, focusing on the combustion equipment. The NOx emissions observed during startup showed that the high chlorine content found in hazardous waste, typically 3% to 20% of feed, may be a significant factor in NOx formation. The results of attempts to control NOx emissions with operating procedures are discussed. Recent Plant Designs The design team lacked operating data for hazardous waste facilities using 10w-NOx burners or post-combustion NOx removal. Hazardous waste facilities in the late 1980's met NOx regulations without a NOx removal process. Several new hazardous waste incineration facilities have included NOx reduction, either to handle high nitrogen-content waste streams or due to very low emission limits imposed by local regulation. However these facilities were still in the design or construction phase. Aptus Facility Design Kiln and Afterburner The front wall has a liquid burner to provide a stable ignition flame using waste liquids that are blended to provide a consistent feed. Pumpable sl uge and bulk solid wastes are dropped onto the rotating kiln wall where there are burned. Waste in containers, which range from 85 gallon steel overpack drums to 5 gallon plastic buckets, is fed to the kiln through a gate on the feed chute. Kiln exit temperature is controlled between 1500 and 2200 OF. The kiln exit gas enters a rectangular afterburner which has a 3 second residence time. Waste liquid burners, mounted in opposite comers, are used to raise the gas temperature to the mandatory range of 2012 to 2300 F. (1000 +/- 100 C.). Aqueous liquid wastes are incinerated in the afterburner usirig a simple air atomized spray ( , I I {)Dp- t l6QcG,- )1 |