Process modeling and on-line monitoring of benzene and other species during the two-stage combustion of ethylene in air

The on-line measurement of combustion effluents is important in the study of reaction mechanisms, process control, and environmental monitoring and impact. Microtrap gas chromatography for real-time analysis of volatile organics preconcentrates the sample, and uses rapid desorption to yield low detection limits with a relatively rapid analysis. This technique is used here for the on-line monitoring of low levels of benzene, a known precursor to polyaromatics and dioxins, produced during the combustion of ethylene in air. In addition, several other species are monitored by more conventional on-line methods. Process modeling with detailed reaction mechanisms of the combustion runs provided reasonably good simulations of the observed concentrations.