OCR Text |
Show the benzene ring for radical addition or hydrogen abstraction , and it also contains a weaker nitrogen-hydrogen bond (86 . 4 kcal/mole) [12J which is susceptible to hydrogen a bst r action . The series of chlo r i nated be nzenes ranges from the most stable, chlorobe nze ne (T 99 = 99°C), to the least stable, pentachlorobenzene (T99 = 94 0 °C). This trend suggests that chlorine displacement by hydrogen is the operat i ve destruction pathway. The rate of reaction simply increases with increasing number of reactive sites, viz.,number of chlorines. Hexachlorobenzene has not yet been tested, but would be expected to be less stable than pentachlorobenzene. The observed T99 of 950°C for benzene falls in the middle of the stability range for the chlorinated benzene group. This is somewhat surprising and indicates that abstraction (and less likely, addition) pathways may be operative in the decomposition of 1,2,4,5 tetrachlorobenzene and pentachlorobenzene. Conclusions and Recommendations The results obtained on the 36 test compounds indicate that there is a significant spread in the thermal stability of hazardous organic compounds with the highest T99 of 99°C for chlorobenzene and the lowest T99 of 600C. This spread will be even larger for the full Appendix VIII listing with nitrosoamines having T99s of approximately ~ 200C and hydrogen cyanide with an expected T99 of greater than 1000oC. Clearly more data is needed to rank the incinerability of ap-proximately 500 Appendix VIII organics. Although many of the test compounds followed expected trends, others, did not. An after the |