Thermal pyrolysis of halon 1211 (CBrClF2), diluted in nitrogen, in a tubular alumina reactor, has been studied over the temperature range of 773-1073 K at residence times from 03 to 2 s. At temperatures below 973 K, the major products were CCl2F2, CBr2F2, C2Cl2F4, C2BrClF4, C2F4, and C2Br2F4. Further increasing temperature resulted in the formation of CBrF3, CClF3, and many other species whose formation necessitated the rupture of C-F bonds. Coke formation was also observed on the surface of the reactor at high temperatures. A kinetic reaction scheme involving 16 species and 25 reaction steps was developed and applied to model the thermal pyrolysis of halon 12 11 over the temperature range of 773-973 K. Sensitivity analysis suggests that the reaction CBrClF2 + CClF2 --> CCl2F2 + CBrF2 constitutes the major pathway for the decomposition of halon 1211 under the conditions investigated.
International Journal of Chemical Kinetics Vol. 37, no. 3, p. 134-146