Experimental study on the thermal oxidation of 1,3-hexachlorobutadiene at 500 – 1100° C

Thermal degradation processes of 1,3-hexachlorobutadiene (C4Cl6) have been studied using a tubular flow reactor at 1 atm over the temperature range 500–1100°C for residence times of 2 seconds. Kinetic studies were performed with mixtures of 1000 ppmV of C4Cl6 in air. Overall Arrhenius parameters for the destruction of C4Cl6 were determined between 700 and 850°C. About 30 molecular halogenated products from C1 to C8 formed by pyrolysis or oxidation of 1,3-hexachlorobutadiene over the investigated temperature range were identified. Concentration profiles of major products ( CO2, Cl2, CO, COCl2, C2Cl4, CCl4) and some minor products (C3Cl4O, C4C14O, C6Cl6, C3Cl4 and C3Cl6) have been measured as a function of temperature. Phosgene is the major chlorinated intermediate product. Detection of some aromatics such as hexachlorobenzene and octachlorostyrene show the importance of the molecular growth pathways in the thechemical mechanism. Reaction pathways of main products are proposed and corresponding reaction enthalpies are estimated.