Reaction networks and dynamics of isopropyl acetate hydrogenation to produce dual alcohols

Hydrogenation of carboxylic acid esters to prepare alcohols is a green and atom-economy process. Ethanol and isopropanol production via isopropyl acetate hydrogenation catalyzed with 20Cu-8ZnO/SiO₂-5K₂O was studied. The reaction mechanism and network were proposed by analyzing the roles of catalyst components, as well as the composition and distribution of reaction products. After eliminating internal and external diffusion resistance, intrinsic kinetic data in a fixed bed reactor with three temperature control sectors were studied under the conditions of: feeding hydrogen ester molar ratio 30~60, isopropyl acetate feed flow 0~0.20 mL·min^-1 and reaction temperature 250~280℃ at 5.0 MPa. Intrinsic dynamic models were established and the model parameters were fitted after simplification of the reaction network. Moreover, the applicability of the model was discussed by studying the physical meaning of the model parameters. Results show that the internal and external diffusion resistance is eliminated when the flow rate of isopropyl acetate is over 0.04 mL·min^-1 and the catalyst particle size is below 0.30 mm. The results obtained by nonlinear least-square methods using Matlab are in good agreement with the dynamic experimental data, which means the established intrinsic kinetic models are suitable for the experimental conditions studied.