Kinetics and mechanism of desulfurization and denitrogenation of coal-derived liquids. Thirteenth quarterly report, June 21-September 20, 1978

Studies of competing hydroprocessing reactions catalyzed by Ni-Mo/..gamma..-Al/sub 2/O/sub 3/ and involving quinoline, indole, dibenzothiophene, and naphthalene in n-hexadecane show that marked interactions exist. The naphthalene hydrogenation rate is markedly reduced by the presence of quinoline; whereas the reactivity of quinoline is virtually unchanged by the presence of naphthalene. Similarly the rate of hydrodenitrogenation of indole, a non-basic nitrogen-containing compounds is strongly reduced by the presence of quinoline, whereas the rate of hydro-denitrogenation of quinoline, a basic nitrogen-containing compound, is unaffected by the presence of indole. The hydrogenation reactions in the dibenzothiophene reaction network are inhibited severely as indicated by the reduction in their pseudo first-order-rate constants as are the hydrogenation reactions for naphthalene. Thus the hydrogenation rate is reduced 30-fold by increasing the initial quinoline concentration from 0.0 to 0.5 wt % in naphthalene hydrogenation and in dibenzothiophene hydrodesulfurzation. The rate of direct sulfur removal is reduced by only 3-fold by increasing the quinoline concentration from 0.0 to 0.5 wt %. These results clearly show that the rate expressions for the hydrotreating reactions are of the form given in the text.