OCR Text |
Show is, of course, not currently available. However, less information is required to estimate the relative DE (viz . , incine rability ranking) of potential POHCs. Simple conceptual and more complex computer models suggest that the gas-phase residence time, temperature, and reaction atmosphere in the post-flame or thermal zones of incinerators control the relative emissions of most POHCs. [3-5] The basic reasoning behind this is that all molecules entering the flame zone of an incinerator are essentially destroyed and only the small fraction of the material escaping the flame zone may be emitted from the facility. Various flame zone "failure modes" exist which may cause residual POHCs to be emitted. Once in the post-flame zone, gas-phase thermal decomposi-tion kinetcs controls the rate of POHC destruction and formation and destruction of products of incomplete combustion (PICs). Even with the simplified hypothesis that post-flame thermal decomposition properties control relative emission rates of organics, a number of complex variables are still involved. Our goal is to develop a procedure whereby the relative incinerability of POHCs may be determined in the laboratory under a standardized set of test conditions. The first assumption that must be made is that all of the POHCs in a given waste stream experience the same post-flame gas-phase residence time, temperature, and reaction atmosphere. This ~ requires that mixtures of POHCs are volatized at nearly the same rate. Preliminary calculations suggest that this is the case for liquid droplets containing chlorinated hydrocarbons, however, further ) |