OPTICAL DIAGNOSTICS IN CHC COMBUSTION

Recent progress is reviewed in the development of laser-based resonance ionization spectroscopy for the continuous monitoring of toxic emissions from municipal and hazardous waste incinerators. Resonance ionization spectra obtained for chlorinated benzenes, ethylenes, and napthalenes in a jet-cooled molecular beam with time-of-flight mass selection exhibit the sensitivity and selectivity required for real-time CHC monitoring at part-per-billion level. The use of resonance ionization spectroscopy for in situ measurements of the density profiles of radical intermediates in laboratory flames may provide a useful supplement for conventional molecular beam mass spectrometry in studies of CHC combustion mechanisms. The radicals H, O, CH3, HCO, CCL, CLO and CHCL2, of importance in the combustion of CHCs, have been recently detected with resonance ionization methods.