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Kinetics of the hydroprocessing of anisole, a compound representative of lignin-derived bio-oils, catalyzed by a commercial sulfided CoMo/Al2O3, was determined at 8–20 bar pressure and 573–673 K with a once-through flow reactor. The catalyst was sulfided in an atmosphere of H2 + H2S prior to the measurement of its performance. Selectivity-conversion data were used as a basis for determining an approximate, partially quantified reaction network showing that hydrodeoxygenation (HDO), hydrogenolysis, and alkylation reactions take place simultaneously. The data indicate that these reactions can be stopped at the point where HDO is virtually completed and hydrogenation reactions (and thus H2 consumption) are minimized. Phenol was the major product of the reactions, with direct deoxygenation of anisole to give benzene being kinetically almost insignificant under our conditions. We infer that the scission of the Cmethyl–O bond is more facile than the scission of the Caromatic–O bond, so that the HDO of anisole likely proceeds substantially through the reactive intermediate phenol to give transalkylation products such as 2-methylphenol. The data determine rates of formation of the major primary products. The data show that if oxygen removal is the main processing goal, higher temperatures and lower pressures are favored.

Catalytic hydroprocessing of 4-methylanisole as a representative of lignin-derived bio-oils was catalyzed by a commercial sulphided CoMo/γ-Al2O3 catalyst in a fixed-bed flow reactor at various space velocities, temperatures, pressures, and feed compositions. An approximate reaction network is presented that accounts for the major products, and approximate kinetics are also presented. The kinetically significant reactions are 4-methylanisole conversion to (a) 4-methylphenol via hydrogenolysis, (b) toluene and benzene via hydrodeoxygenation, (c) cyclohexanone and methylcyclohexanone via hydrogenation, and (d) methylphenol derivatives via alkylation and transalkylation. The formation of toluene and benzene along with water and methanol from 4-methylanisole is inferred to result from direct scission of the Caromatic-O bond. Cleavage of the Cmethyl-O bond is faster than cleavage of the Caromatic-O bond. The main pathway to toluene formation is the hydrogenolysis of the Caromatic-O bond of the intermediate 4-methylphenol. [ABSTRACT FROM AUTHOR]