The oxidation of trichloroethene with methane: experiment and kinetic modeling

摘要

The oxidation of C_2HCl_3 with industrial grade CH_4 has been studied in a laboratory-scale flow reactor under fuel-rich, stoichiometric, and fuel-lean conditions from 575 to 850℃, with an average gas residence time of 0.3-1.5 s. The major products, C_2Cl_2, C_2H_4, CO, CO_2, and HCl, were found at lower temperatures with high [O_2]. The minor intermediates included C_2H_3Cl, C_2HCl, CH_3Cl, COCl_2, trans-CHClCHCl, cis-CHClCHCl, trans-ClHC=CClCH_3, C_6H_6, C_3s, C_4s, Cl_2, and other C_6 compounds. Writing -d[C_2HCl_3]/dt = k[C_2HCl_3]; global values of k (s~(-1)) were found to be 3.21 x 10~6 exp(-116 (kJ/mol)/RT), 1.61 x 10~6 exp(-112 (kJ/mol)/RT), and 1.27 x 10~6 exp(-112 (kJ/mol)/RT), respectively, for fuel-lean, stoichiometric, and fuel-rich conditions. Modeling with a detailed mechanism involving 149 species and 795 elementary reactions revealed that C_2HCl_3 mainly disappears via C_2HCl_3 → C_2Cl_2 + HCl. Sensitivity analyses were performed to rank the significance of every reaction in the mechanism. Agreement between modeling and experiment was satisfactory for most major species.