Catalytic hydrogenolysis of renewable substrates to prepare polyols

Heterogeneous hydrogenolysis of glycerol to propylene glycol was carried out in both batch and trickle bed reactors. A kinetic study was done in both reaction systems by changing temperature, pressure, glycerol concentration, base concentration, and catalyst loading. Different solvents were tested to determine to what extent the solvent affected kinetics. The catalysts prepared by our collaborator were characterized.;A combined mass transfer-kinetic model, which integrated mass and energy balances, was developed and optimized to find kinetic parameters for the reaction. Prediction of outlet glycerol concentration and temperature profile with model was in good agreement with experimental data. In order to improve model's prediction accuracy, empirical correction factor was numerically fitted; adjusted model gives more accurate prediction and facilitates the understanding of overall reaction rate and its components in the model. Moreover, model's assumptions were examined and checked by developing simplified models.;Finally, lactic acid hydrogenation to prepare propylene glycol was studied in batch and trickle bed reactors with the same reaction conditions to correlate their intrinsic reaction rates. The research shows both reactors, under the intrinsic reaction regime, are correlated. Simulation was performed with the model incorporating the intrinsic kinetics specifically developed for lactic acid hydrogenation, and results are in good agreement with experimental data.