HYDROTREATING REACTION OF 4,6-DIMETHYLDIBENZOTHIOPHENE AND CARBAZOLE AS PETROLEUM MODEL COMPOUNDS OVER NI-MO AL2O3 IN THE PRESENCE OF SATURATED-HYDROCARBON SOLVENTS/

Hydrotreating reaction of 4,6-dimethyldibenzothiophene (DMDBT) and car bazole (CBZ) as heteroatom-containing petroleum model compounds and bi phenyl (BP) was examined without any solvent or with a solvent such as cyclohexane or decalin to obtain basic information on the effect of a ddition of saturated hydrocarbon solvents on the reaction. The treatme nt was conducted with a presulfided Ni-Mo/Al2O3 catalyst under 70 kg/c m(2) of hydrogen (at room temperature) at 300-350 degrees C in a batch autoclave. It was observed that, irrespective of the substrates, both conversion and hydrogen consumption in the reaction increased in the order: no solvent < decalin < cyclohexane. In the treatment of DMDBT i n n-paraffins in the range of C-6-C-12, it was also observed that the reaction was relatively more promoted as their chain lengths became sh orter. These results are discussed in terms of diffusivity of the subs trates in the reaction medium.