Catalytic steam reforming of chlorocarbons: Methyl chloride

This paper reports a novel catalytic process for the destruction of chlorinated hydrocarbons. Based on CH4-steam reforming reactions, the approach gives high levels of conversion (5-nines possible) at high space velocities (2-3 x 10(5) h(-1)) and temperatures (650-750 degrees C). Products comprise CO, CO2, H-2 and HCl and no others were identified. Rapid deactivation by parallel thermal pyrolysis reactions occurs if high conversion is not maintained. The presence of Cl species poisons CH4-steam reforming and water gas shift activities, but the effect is only temporary and disappears when the Cl compounds are removed from the feed. Kinetic studies on methyl chloride have been carried out and show a Langmuir-Hinshelwood type behavior, from which a proposed mechanism involving dual-site surface dissociation is suggested. Comparisons with other common chlorocarbons show similarities, with the exception that 1,1,1-trichloroethane is very sensitive to thermal pyrolysis and gives faster deactivation.