COMBUSTION PROCESSES are extremely difficult to characterize in terms of the chemical processes occurring. This is in part the result of high temperatures and the use of complex fuels. The resultant combustion streams are composed of a variety of species which include radicals, ions, stable molecules, and condensed matter such as soot and fly ash. This complex environment leads to a myriad of homogeneous reactions as well as heterogeneous reactions occurring at the surface of entrained particles. The heterogeneous reactions are further complicated by the presence of trace metals and clay materials which can act as catalysts.