TY - JOUR
T1 - Modelling of kinetic and transport effects in aldol hydrogenation over metal catalysts
AU - Salmi, Tapio
AU - Rantakylä, Tiina Kaisa
AU - Wärnå, Johan
AU - Mäki-Arvela, Päivi
AU - Kuusisto, Jyrki
AU - Martinez, Izacar
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002/5/16
Y1 - 2002/5/16
N2 - This work concerned the pathway from intrinsic kinetics to diffusion-affected kinetics in catalytic hydrogenation. Kinetics and mass transfer effects in the liquid-phase hydrogenation process of an aldol (2,2-dimethylol-1-butanal) to the corresponding triol (trimethylol- propane) were studied in a semibatchwise operating autoclave, where finely dispersed and large catalyst particles were used. The intrinsic hydrogenation kinetics was determined with the crushed catalyst particles at 40-80 bar H2 and 50-90°C in isobaric experiments. A kinetic model based on competitive adsorption and surface reaction between the aldol and hydrogen was successfully fitted to the experimental data. Physical measurements of the density, viscosity as well as hydrogen solubility in the reaction mixture were carried out. The measurements revealed that the governing factor in the physical data is the temperature dependence, while the composition dependence during the hydrogenation is a minor factor under the actual experimental conditions. The models for intrinsic kinetics, physical properties and mass transfer effects were combined to describe the behaviour of large catalyst particles. It turned out that the theoretically developed model agreed well with experimental observations made with large-size catalyst particles. The approach is suitable for the scale-up of catalytic hydrogenation processes.
AB - This work concerned the pathway from intrinsic kinetics to diffusion-affected kinetics in catalytic hydrogenation. Kinetics and mass transfer effects in the liquid-phase hydrogenation process of an aldol (2,2-dimethylol-1-butanal) to the corresponding triol (trimethylol- propane) were studied in a semibatchwise operating autoclave, where finely dispersed and large catalyst particles were used. The intrinsic hydrogenation kinetics was determined with the crushed catalyst particles at 40-80 bar H2 and 50-90°C in isobaric experiments. A kinetic model based on competitive adsorption and surface reaction between the aldol and hydrogen was successfully fitted to the experimental data. Physical measurements of the density, viscosity as well as hydrogen solubility in the reaction mixture were carried out. The measurements revealed that the governing factor in the physical data is the temperature dependence, while the composition dependence during the hydrogenation is a minor factor under the actual experimental conditions. The models for intrinsic kinetics, physical properties and mass transfer effects were combined to describe the behaviour of large catalyst particles. It turned out that the theoretically developed model agreed well with experimental observations made with large-size catalyst particles. The approach is suitable for the scale-up of catalytic hydrogenation processes.
KW - Kinetics
KW - Liquid-phase hydrogenation
KW - Physical properties
KW - Porous catalyst particles
KW - Production of triols
KW - Reaction-diffusion model
UR - http://www.scopus.com/inward/record.url?scp=0037117937&partnerID=8YFLogxK
U2 - 10.1016/S0009-2509(02)00047-7
DO - 10.1016/S0009-2509(02)00047-7
M3 - Article
AN - SCOPUS:0037117937
SN - 0009-2509
VL - 57
SP - 1793
EP - 1803
JO - Chemical Engineering Science
JF - Chemical Engineering Science
IS - 10
ER -