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Show INTRODUCTION This paper summarizes an analysis of the emissions data generated in a parametric testing project sponsored by the U.S. Environmental Protection Agency (EPA) at the Montgomery County South municipal waste combustion (MWC) facility in Dayton, Ohio. The primary goals of the test project were to examine the effects of ESP operating temperature on chlorinated dibenzo-pdioxins (CD D) and chlorinated dibenzofurans (CDF) formation and capture, to examine the potential benefits of sorbent injection in controlling acid gas and CDD/CDF emissions, and to evaluate the effects of combustion conditions on the formation and emissions of CDD/CDF. This paper presents an evaluation of CDD/CDF formation in the Montgomery Incinerator and identifies conditions needed to reduce formation and emissions of CDD/CDF. FACILITY DESCRIPTION The MWC unit tested at the Montgomery County South Facility is illustrated in Figure 1. The combustor zone consists of a refractory-lined ignition chamber with reciprocating grates, a rotary kiln, and a mixing chamber. Gas-phase combustion products exit the ignition chamber either through the kiln or through a bypass duct situated above the kiln. The split-flow streams reconverge in the mixing chamber downstream of the kiln and flow into a conditioning (quench) chamber where water sprays reduce the gas temperature. The conditioned gas passes through a crossover duct, through a three-field electrostatic precipitator (ESP), and into the stack. Combustion air which is supplied primarily as underfire air in the ignition chamber is controlled by an induced draft fan located downstream of the ESP. A forced-air fan is used to supply ovemre air at one location on each side of the furnace in the ignition chamber. During the test project combustion conditions were established by controlling the induced draft fan setting, the rate of waste feed to the ignition chamber, and the rotation speed of the kiln. These system parameters were used to control the temperature at the exit of the ignition chamber and in the mixing chamber. In spite of shortcomings relative to modern MWC design practice, the incinerator operators were able to maintain combustion conditions, as defined by the temperature setpoints in both the ignition chamber and mixing chamber, within acceptable tolerances. 3 |
