| This dissertation was concerned with a systematic study of the hydrogenation-hydrodeoxygenation (HDO) reactions of aromatic ethers, phenols, and oxygen-rich synfuels. The feeds investigated included diphenyl ether; dibenzyl ether; anisole (methoxybenzene); dibenzofuran; 2,3-benzofuran; phenol; 2-naphthol; 2-phenylphenol; and three types of oxygen-rich synfuel feedstocks, i.e., peat-derived bitumens; fir-root bitumen, and a low-temperature coal depolymerization product. The studies were performed in autoclave reactors between 110-370(DEGREES)C and hydrogen pressures between 250-2000 psig using sulfided CoMo/(gamma)-Al(,2)O(,3) and NiMo/(gamma)-Al(,3)O(,3) as catalysts. Changes in product composition as a function of experimental variables (reaction temperature, hydrogen pressure, reaction time, catalyst type, and H(,2)S (CS(,2)) concentration were determined. Kinetic rate constants and activation energies for each step in the reaction network of the structurally distinct model compounds were calculated, and mechanistic aspects of the HDO reactions elucidated.; It is found that the rate of C-O hydrogenolysis depends on the C-O bond dissociation energy and that the relative ease of HDO is in the order: dibenzyl ether > diphenyl ether > dibenzofuran. The higher resistance to C-O hydrogenolysis of dibenzofuran can be ascribed to stabilization of the C-O bond by conjugation of the furanic ring with the two condensed benzene rings. For phenolic compounds, the HDO rates are dependent on the nature of the ring system and of the substituents. The relative HDO rates found were in the order: 2-naphthol > phenol > 2-phenylphenol. The HDO reactions are sensitive to steric and induction effects. Addition of H(,2)S (CS(,2)) during the HDO process decreases the C-O hydrogenolysis of the sulfided catalysts.; Hydrotreatment of highly aliphatic Swedish peat-derived bitumens between 290-370(DEGREES)C and pressures of 2100-3000 psig in the presence of a sulfided 6%Co8%Mo catalyst, produces a high quality hydrocarbon oil containing < 1.0 wt % of oxygen and 92-96 wt % of distillables, including 48-53 wt % of gasoline, kerosene, and light gas oil fractions. Under the same conditions hydrotreatment of a low-temperature depolymerization product from Wyodak coal yielded a hydrocarbon oil containing 92.5 wt % of distillables including 34.9 wt % of components boiling between 50-325(DEGREES)C. |
