Catalytic hydrodechlorination of monochlorobiphenyls using Ni-Mo/gamma-Al2O3 sulphided catalyst

The hydrodechlorination of monochlorobiphenyls has been studied in the presence of a sulphided Ni-Mo/gamma-Al2O3 catalyst. The reaction runs were carried out in a stirred batch reader in the presence of hydrogen, at constant pressure (p(H2) = 40 bar). Hexadecane was used as a reaction medium. The reaction temperature was varied in the range 250-350 degrees C. The hydrodechlorination kinetic constants and the corresponding parameters of Arrhenius' law were evaluated. The calculated values of the kinetic constants permit us to determine that the HDCl rate of monochlorobiphenyls is independent of the position of the chlorine atom and is higher than that of chlorobenzene by a factor of about two. The results obtained can be useful in modelling PCB hydrodechlorination.