| OCR Text |
Show By-Product Emissions The injection of ammonium sulfate into the furnace has a potential of producing unwanted emissions such as NH3 and S02/S03. A series of exhaust measurements were made to evaluate the slip of ammonia using selective ion electrode and the emissions of S02 and S03. via controlled condensation. Table 1 summarizes measurements made during the Indiana coal tests. Exhaust NH3 concentrations were negligible in all cases, including those obtained with Utah coal and natural gas as the primary fuel. Higher SO emissions were obtained with 10 percent gas reburning. However, the uncontrolled S02 1 eve 1 was ma i nta i ned wi th 20 percent gas reburn i ng due to d i 1 ut ion. No increase in S03 emissions was observed for both cases, suggesting favorable conversion of the sulfate to S02. Thus, there exi sts a control strategy to prevent an increase in SO emissions due to the injection of ammonium sulfate. For the application of advanced reburning to high sulfur coals, 10 percent gas reburning is recommended, whereas for low sulfur coal applications, the 20 percent gas reburning concept is preferred. CONCLUSIONS In summary, these results suggest that selective reducing agents can be combined with combustion modification techniques to provide NO¥ reductions that are larger than those that are possible by applying the technologies simultaneously but separately. By using the stoichiometry control associated with reburning to produce a slightly fuel rich region for selective reducing agent injection, reductions can be achieved at relatively low temperatures without the use of stainless steel or other catalysts. In principle, this technology could have broad application to fossil fuel fired furnaces and boilers, stationary gas turbines, and internal combustion engines. ACKNOWLEDGEMENTS This work was primarily supported by the U.S. Department of Energy, Pittsburgh Energy Technology Center (Contract No. DE-AC22-86PC91025) with Dr. Richard Tischer as the Project Manager. We also would like to acknowledge the contributions of our colleague Mr. Loc Ho in conducting the experiments. DISCLAIMER Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. REFERENCES 1. Wendt, J. o. L., et al., 17th Int1. Symp., Combustion Institute (1979). 2. Chen, S. L., et at., 21st Intl. Symp., Combustion Institute (1987). 3. Lyon, R. K., Hydrocarbon Processing, 58, 10 (1979). 4. Arand, J. K., et al., U.S. Patent No. 4,208,286 (1980). 5. Perry, R. A. and D. L. Siebers, Nature, 324, 18/25 (1986). 6. Heap, M. P. et al., Nature, 335, 619, (1988). 7. Chen, S. L. et al., JAPCA, Vol. 39, No. 10 (1989). 5 |
