Kinetic study of the pyrolysis of tetrachloroethylene in a hydrogen rich environment

Experiments on pyrolysis of C2Cl4 with hydrogen in argon bath gas (C2Cl4: H2: AR=0.5:7:92.5) were performed in a laboratory scale flow reactor, to determine reaction paths and kinetic parameters, plus to observe hydrogen as a source to convert chlorocarbons into hydrocarbons and HCl. The reaction was carried out at 1 atmosphere total pressure in the tubular flow reactor, over temperature ranges from 575 to 850 °C, with average residence times in the range of 0.3 to 1.2 s. The major reaction products were C2HCl3, CH2CCl2, C2H6, C2H4 and HCl. Trace intermediates including CH4, C2H2, C3H6, C3H4, C4H8, C4H6, C4H4, C2H3Cl, C2HCl, trans-CHClCHCl, cis-CHClCHCl C2Cl2 and aromatic compounds were found. The equation for overall loss of C2Cl4 (k (s−1)) was 1.35×106exp(−27055/RT). This study shows that C2H4 became the major product for reaction temperatures higher than 700 °C, and became one of the final products together with HCl. iled kinetic mechanism consisting of 202 elementary reactions with 59 species was developed to model the results obtained from the experiments. Sensitivity analyses were performed to rank the significance of each reaction in the mechanism. Modeling and sensitivity analysis revealed that C2Cl4+H→C2HCl3+Cl, C2Cl4+H→C2Cl3+Cl, and C2Cl4→C2Cl3+Cl are the primary reactions for the decomposition of C2Cl4.