Experimental and computational studies of the thermal decomposition of halon 1211

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 0.3 to 2 s. At temperatures below 973 K, the major products were CCl2F2, CBr2F2, C2Cl2F4, C2BrClF4, C 2F4, and C2Br2F4. Further increasing temperature resulted in the formation of CBrF3, CCLF 3, 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 1211 over the temperature range of 773 - 973 K. Sensitivity analysis suggests that the reaction CBrClF2 + CClF2 → CCl 2F2 +CBrF2 constitutes the major pathway for the decomposition of halon 1211 under the conditions investigated