Application of Staged Combustion and Reburning to the Co-Firing of Nitrogenated Wastes: Chemical and Biological Analyses

摘要

The paper gives results of an evaluation of a 0.6 MW precombustion chamber burner, designed for in-furnace NOx control and high combustion efficiency (CE) for high nitrogen content waste co-firing. The 250- to 750-ms residence time precombustion chamber burner mounted on a prototype water-tube package boiler simulator used air staging and in-furnace natural gas reburning to yield up to four stoichiometric zones. Natural gas doped with ammonia and No. 2 distillate fuel oil doped with pyridine were used to simulate high nitrogen content fuel/waste mixtures. Minimum NO emission levels correspond to about 85% reduction in NOx emissions compared to uncontrolled emissions from a conventional swirl burner mounted on a 0.7-MW commercial package boiler. CO emissions for these burner characterization tests indicated CEs>999%. The low NOx precombustor was then used to examine the co-firing characteristics of a nitrogenated pesticide containing dinoseb in a fuel-oil/xylene solvent. The dinoseb formulation as fired contained 6.4% nitrogen. NO emissions without in-furnace NOx control exceeded 4400 ppm (at 0% O2). When NOx controls in the form of air staging and natural gas reburning were employed, these emissions were reduced to