Kinetic study of the gas-phase hydrogenation of aromatic and aliphatic organochlorinated compounds using a Pd/Al 2O 3 catalyst

Abstract

The hydrodechlorination of dichloromethane (DCM), tetrachloroethylene (TTCE), chlorobenzene (CBZ) and 1,2-dichlorobenzene (DCBZ), all of them alone and in mixtures, over a commercial Pd/Al 2O 3 catalyst in a continuous packed-bed reactor was studied in the present work. Results indicate that the reaction kinetics for the single compounds are pseudo-first order kinetics. The reactivity of the compounds studied is very different. So, whereas aromatic compounds and tetrachloroethylene can be fully converted at the operation conditions reported in this work, dichloromethane conversions are lower than 30% in all the cases. The hydrodechlorination of mixtures of organochlorinated compounds shows important inhibition effects, these effects increase as the number of chlorine atoms in the molecule increase. Reaction kinetics for the hydrogenation of mixtures can be represented by a Langmuir–Hinshelwood model.