Combustion and precombustion control methods to minimize emissions from modular incinerators

This dissertation summarizes the results of stack emission measurements made since 1988 using a two-stage 500 lb/hr modular incinerator located at the University of Florida-Tacachale-Clean Combustion Technology Laboratory (UF-T-CCTL). From the analysis of these results some statistically significant relationships have been developed between HCl emissions (a surrogate for PVC in the waste) and the emissions of a number of chlorinated organic compounds ({dollar}rm Csb6Hsb5Cl{dollar}, {dollar}rm Csb6Hsb4Clsb2{dollar}, {dollar}rm CHClsb3{dollar}, {dollar}rm CHsb2Clsb2{dollar}, and {dollar}rm Csb2Clsb4{dollar}). These compounds appear in the stack gases even under good combustion conditions. These type of relationships have not been previously reported in combustion literature and have important implications for the evolving discipline of Clean Combustion Technology. These results contradict widely quoted and widely accepted conclusions from other incinerator studies.; From the analysis of the stack emissions of the UF-T-CCTL incinerator a control strategy is developed that will minimize emissions of carbon monoxide and volatile organic compounds. A personal computer-based control system is developed to implement the combustion control strategy. The control system monitors carbon monoxide, carbon dioxide, oxygen, and hydrogen chloride emissions and incinerator and stack temperatures; maintains feed rate and output power levels; and fixes temperature levels in such a way as to operate the incinerator under desirable combustion conditions for emissions minimization.; The control system's strategy is based upon a review of previous combustion conditions and emissions data collected from the UF-T-CCTL incinerator, kinetic modelling of emissions, regulatory constraints, incinerator size and thermal characteristics, and desired feed rate and output power levels. The control system regulates the flow rates of natural gas into the two combustion chambers, primary chamber overfire and secondary chamber air flow, and waste charging frequency.; Experiments at an average 350-lb/hr waste feed rate with the control system installed and operating show a significant reduction in carbon monoxide emissions over those from before the installation of the control system. Also, the temperature versus time profile during incinerator operation has been considerably smoothed out.