Burning rate enhancement and soot reduction through blending in chlorinated waste incineration

An experimental investigation has been conducted on the droplet combustion of mixtures of chlorinatedhydrocarbons in a hot, oxidizing environment, with emphasis on binary mixtures consisting of a lightly chlorinated hydrocarbon and a heavily chlorinated hydrocarbon. The rationale is that, by using a lightly chlorinated combustible waste instead of regular fuel oils to assist in the destruction of an incinerationresistant heavily chlorinated waste, both wastes can be simultaneously destroyed without the cost expediture for the fuel oil feed stock. Results indeed demonstrate that the heavily chlorinated tetrachloroethane (TECA) can be made to burn vigorously with the addition of only about 20-25% of the lightly chlorinated, equally volatile chloroheptane or dichlorobutane. It is further shown that this result can be approximately correlated by the mixture chlorine-to-hydrogen ratio, Cl/H, in that in the lightly to moderately chlorinated regime of Cl/H<1, the flame temperature and hence the buring rate are only moderately reduced with increasing chlorination, and decreasing heat release, because of the reduced stoichiometric need for air. However, for the massively chlorinated regime of Cl/H>1, the flame temperature and burning rate decrease quite rapidly with increasing chlorination because now reduction in heat release dominates. The results also show that while the lightly chlorinated hydrocarbon promotes burning of the heavily chlorinated hydrocarbon, the latter tends to substantially reduce the extent of soot formation from the former. The mutual benefit associated with the blending approach studied herein is emphasized.