COMPARISON OF CARBON-SUPPORTED AND ALUMINA-SUPPORTED MO, COMO AND NIMO CATALYSTS IN PARALLEL HYDRODENITROGENATION AND HYDRODESULFURIZATION

The effect of support (alumina, active carbon) and promoter (Co, Ni) on activity and selectivity of Mo catalysts was compared in parallel hydrodenitrogenation-hydrodesulphurization (HDN-HDS) of pyridine and thiophene at 320-degrees-C and 2MPa of hydrogen pressure. Two commercial CoMo/alumina and NiMo/alumina catalysts were included for comparison. The undesirable formation of piperidine was much lower on carbon-supported and unpromoted Mo catalyst than on alumina-supported and Co- or Ni-promoted Mo catalyst. Irrespective of the type of support, the presence of Co or Ni accelerated mainly the HDS reaction; the unpromoted Mo catalysts had therefore better HDN/HDS selectivity than the CoMo and NiMo catalysts.