The mass transfer of hydrogen in fat hydrogenation was studied in two geometrically similar reactors of 30 and 500 liter capacity equipped for hydrogen rec/rculation. A scale-up rule was formulated on the basis of the experiments and checked in industrial hydrogenations with a 24 m 3 reactor. The scale-up rule found was similar to the equal mixing time rule.

The influence of mass transfer steps in the kinetic study of rapeseed oil hydrogenation in a laboratory reactor was estimated. Hydrogenations were carried out at 140–200 C and at 0.3–10 atm hydrogen pressure in the presence of 0.087% of commercial nickel‐on‐kieselguhr catalyst, corresponding to 0.05% of nickel. Despite intense mixing conditions on the macroscale of the bulk oil, corresponding to a reaction rate independent of further increase of the stirrer rate, the concentration differences across the liquid film surrounding the bubbles and the catalyst particles could not be neglected. The pore transport of triglycerides and hydrogen molecules was found not to be a slow step in most hydrogenations.

The kinetics of rapeseed oil hydrogenation was studied at 140-220C and at 0.3-10atm hydrogen pressure in a laboratory reactor in the presence of 0.05% nickel catalyst. A mathematical model was fitted to the experimental data, and temperature and pressure dependence of the different reaction steps was discussed on the basis of the model. The adequacy of the model was tested by means of a residual analysis.A Guide for Authors is Located in JAOCS 52(January):56A(1975)

in ABSTRACT AND SUMMARYA computational method for fitting a simplified mathematical model of fat hydrogenation reactions to experimental kinetic data is given. The parameters of the mathematical model were estimated by a nonlinear least-squares regression technique, and the minimum search method included was tested on a special function with a narrowed curved valley.