Abstract
Catalytic hydrocracking of Khafji atmospheric residue over 8 catalysts: Co/Al2O3, Ni/Al2O3, Ni/SiO2, Ni/SiO2-Al2O3, Mo/Al2O3, W/Al2O3, NiMo/Al2O3 and NiW/Al2O3 (Table 1) was performed at 400°C and hydrogen pressure of 250kg/cm2 for 3hr. The relation between selectivity for the reaction and composition of the catalysts was investigated. The analytical procedure used for the product is given in reference 9.
Fractional analysis of each product is given in Table 2. The main products were oil that was nondistillable but heptane-soluble and a distillate fraction in the boiling range of 300-415°C. Higher levels of cracking of the residue to distillates were possible over the three-component catalysts (NiMo/Al2O3 and NiW/Al2O3) compared with the two-component catalysts used.
The amounts of hydrogen consumption and the value of H/C of the individual fractions are listed in Table 3. The H/C value of the nondistillable depended on the amount of hydrogen consumption. Mo/Al2O3 and W/Al2O3 catalysts consumed more hydrogen than the other two-component catalysts and the amount of hydrogen consumption of the three-component catalysts was approximately 3/2 times that of Mo/Al2O3 and W/Al2O3 catalysts.
The contents of sulfur and nitrogen are listed in Tables 4 and 5, respectively. When molybdenum-containing catalysts were used, both desulfurization and denitrification proceeded to higher levels compared with tungsten-containing catalysts.
The role of nickel metal in the three-component catalysts was discussed.
