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Show ULTRA LOW NOx DESIGN FOR THERMAL OXIDATION OF WASTE GASES INTRODUCTION Nitrogen Oxides (NOx) are one of six chemical species classified as criteria pollutants under the National Ambient Air Quality Standards (NAAQS) of the Clean Air Act. NOx in combination with Volatile Organic Compounds (VOC) present in the atmosphere can combine in the presence of sunlight to form ozone. Ozone has been found to be damaging to human health in concentrations as low as 0.1 ppmv. In 1992, the EPA reclassified areas of the United States for attainment of NAAQS standards. 185 areas were classified as non-attainment for ozone. Both the federal government, through the 1990 Clean Air Act (CAA) Amendments, and individual states are stringently regulating NOx emissions from combustion sources because of their adverse affect on human health. Rules recently proposed in response to the 1990 CAA Amendments are intended to reduce NOx emissions from utility and other stationary sources by 2.5 million tons annually. Virtually every thermal oxidizer inquiry Process Combustion Corporation (PCC) receives contains a NOx emission limit. Current limits are only a small fraction of those allowed just a few years ago. In many ozone nonattainment areas, existing major sources must be retrofitted with Reasonably Available Control Technology (RACT). New sources must be controlled to meet Lowest Achievable Emission Rates (LAER). NOx emissions from new sources must be offset by reductions elsewhere in the region at a ratio over 1:1. States must continue to tighten NOx limits until the NAAQS for ozone is attained. No regulations are more severe than those applied by the California South Coast Air Quality Management District (SCAQMD). Two SCAQMD rules apply to NOx emissions from gas fired burners. Rule 1109 limits NOx emissions from boilers and process heaters with a rated heat input greater than 40 MM Btu/Hr to a maximum of 0.03 lb NOx/MM Btu. For boilers, steam generators, or process heaters with rated capacities less than 40 MM Btu/Hr, NOx emissions are limited to 40 ppmv (0.05 Lb/MM Btu). The SCAQMD also has the authority to reduce these limits even further based on Best Available Control Technology if new designs can demonstrate lower NOx emissions. V-30 2 |