Application of Gas Reburning Technology to Glass Furnaces for NOx Emissions Control

Like many other high-temperature industrial processes, glass furnaces produce high concentrations of oxides of nitrogen (NOx) due to the high combustion temperatures required to process the glass batch raw materials. Since increasingly stringent air quality regulations are forcing the glass industry to reduce emissions of NOx, there is significant interest in technologies which can be applied to glass furnaces to achieve high levels of emissions control cost effectively. For glass furnaces, available options for NOx control are either very expensive or have the potential to negatively impact the process. Gas Reburning is a NOx control technology which has successfully been demonstrated on utility boilers to provide moderate to high NOx removal efficiencies at a moderate cost per ton of NOx abated. This paper describes the results of a study to assess the potential for and economics of applying gas reburning technology to industrial glass furnaces. Model furnaces were defined for glass furnaces employed in the manufacturing of flat, container, and fiber glass to permit a detailed evaluation of reburning technology. Conceptual reburning system designs for each model plant were developed to permit the process performance and costs to be established. Chemical kinetic and heat transfer models were used, respectively, to assess the potential reductions in NOx emissions achievable and to evaluate the impacts of the reburning process on the overall furnace thermal efficiency. Costs for application of reburning technology to glass furnaces were developed and compared to other available technologies for control of NOx emissions.