Kinetic Study of Catalytic Hydrogenation of O-Nitroanisole to O-Anisidine in aMicrochannel Reactor

摘要

Hydrogenation reactions are ubiquitous in the fine chemicals and pharmaceuticalrnindustries. The hydrogenation of o-nitroanisole to o-anisidine in methanol was selected as arnmodel three-phase reaction for kinetics study in a packed-bed microchannel reactor using Pdrnmetal supported on zeolite as a catalyst. The kinetics of three-phase hydrogenation reactionsrnin conventional slurry or batch reactors is often limited by mass transfer of hydrogen throughrnthe liquid due to the limited solubility of hydrogen in organic substrates and solvents. Thesernreactions are also highly exothermic, therefore adequate temperature control is of primaryrnimportance to reduce side reactions and to prevent thermal runaway conditions. The use of arnmicrochannel reactor for such reactions provides improved mass and heat transfer rates whichrnmay ensure that the reaction operates close to intrinsic kinetics. In the present study, the raterndata in the intrinsic kinetic regime were analyzed and found to be well represented by L-H typernrate equations. Kinetic experiments were also conducted in a semi-batch reactor under similarrnreaction conditions as the microchannel reactor. The performance of the packed bedrnmicrochannel reactor was compared to that of the semi-batch reactor by evaluating the massrntransfer resistance in each system.