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Show • boilers, with new installations having to produce <20 ppm (note: these regulations have been superseded by the recent RECLAIM program, which incorporates NOx emissions trading. See below). Thus, better burner designs were required. The first low NOx boiler to be developed by GRI recently entered the market. The TurboFire XL ® boiler by DONLEE is a large packaged watertube boiler ranging in size from 1000 to 3000 hp. The boiler uses cyclonic combustion to achieve rapid mixing, which results in lower maximum temperatures and excellent NOx emissions. The 1000 and 1800 hp systems have been tested in the field and yielded NOx <30 ppm, and <20 ppm with steam. The 3000 hp system was recently installed in a chemical plant in Ohio. Field performance results for the latter are expected to be similar. In addition to very low NOX) the cyclonic burner design enhances heat transfer, providing an additional benefit to the user in terms of operating efficiency. The TurboFire XL ® boiler is commercially available. GRI is currently developing a low NOx firetube boiler with a team composed of Altex Technologies and Cleaver-Brooks, a major US firetube boiler manufacturer. The design, which was developed by Altex, involves a burner that simulates a premixed flame. When combined with Cleaver-Brooks' patented Induced Flue Gas Recirculation system, this burner has achieved <15 ppm NOx in an operating 350 hp boiler. The concept is expected to yield <9 ppm NOx when combined with a rich second stage burner. This has yet to be shown in an operating boiler, however. Current plans call for market introduction of the < 15 ppm design in the next year, with the <9 ppm concept anticipated in early 1996. Ultra-low NOx Burners With the advances made by GRI and others, low NOx burners able to meet the near-term NOx emissions requirements are now entering the marketplace. However, a new market driver has surfaced as the NOx emissions regulations have begun to be enforced. Regulations require that new equipment emit from 1.1 to 1.5 times less NOx than the equipment they replace. This presents a problem for expanding plants. Moreover, the availability of relatively low cost retrofit burners gives plant operators the option to offset NOx emissions in their older equipment at a relatively low cost. Finally, emissions credit trading such as the RECLAIM program in California can encourage businesses to lower emissions below the minimum required. Each of these provides an economic driver to over-control NOx emissions. In addition, if past trends are any indicator, even lower acceptable NOx levels can be anticipated, so that what today is over-control will be required tomorrow. Considering these factors, GRI has initiated longer term programs aiming to achieve <5 ppm NOx in boilers and fluid heaters. For boilers, GRI has teamed with COEN and Acurex Environmental to develop a burner that will produce below 5 ppm NOX) less than 30 ppm CO, and that will cost the same as or less than current low NOx burners. Two fluid heater programs have also been started, one by Arthur D. Little with Callidus, and a second by Energy and Environmental Research Corporation with Selas. Finally, GRI has committed to cofund two programs with the 9 |