HYDROGENOLYSIS OF ORGANOCHLORINATED POLLUTANTS - PARALLEL HYDRODESULFURIZATION OF METHYLTHIOPHENE AND HYDRODECHLORINATION OF DICHLOROBENZENE OVER CARBON-SUPPORTED NICKEL, MOLYBDENUM AND NICKEL-MOLYBDENUM SULFIDE CATALYSTS

The sulfide catalysts Ni/C, Mo/C, Ni-Mo/C and Ni-Mo/alumina were compa red in parallel hydrodesulfurization (HDS) of 3-methylthiophene and hy drodechlorination (HDC) of o-dichlorobenzene in a flow reactor at 1 MP a and 300 degrees C. The work was related to the disposal of chlorinat ed organic wastes contaminated by sulfur. The magnitude of the synergi sm in activity between Ni and Mo in the composite Ni-Mo catalyst obser ved both for HDS and HDC was significantly smaller for HDC than HDS. H DC was faster than HDS over all catalysts studied. The Ni/C sample exh ibited the highest selectivity to HDC versus HDS and also surprisingly high HDC activity, which was higher than that of the commercial Ni-Mo /alumina catalyst. It was concluded that HDC and HDS can be uncoupled by changing the active sulfide phase and that significant room exists to develop sulfide HDC catalysts with better activity than the convent ional Go-Mo or Ni-Mo/alumina catalysts.