Esterification of a fatty acid by reactive distillation

A reactive distillation process for the production of decanoic acid methyl esters by esterification of the fatty acid decanoic acid with methanol is presented. The reaction has been catalyzed heterogeneously by a strong acidic ion-exchange resin (Amberlyst 15). A pragmatic kinetic model based on a Langmuir-Hinshelwood-Hougen-Watson approach has been derived and the kinetic constants of this and a pseudohomogeneous model have been fitted. Two different catalytic packings, Katapak-S and Katapak-SP, have been used for reactive distillation experiments. The separation efficiency of Katapak-SP was determined experimentally and reactive distillation experiments in pilot-plant columns have been performed. Operation conditions have been varied (reflux ratio and reactant ratio) experimentally. An equilibrium stage model is capable of describing the experiments quantitatively when the adsorption based a kinetic model is applied. Simulation has been used subsequently to determine the influence of important operating and design factors (reactant ratio, reflux ratio, pressure, distillate-to-feed ratio, size of the reactive section, and role of a prereactor) and to compare the packings systematically. Finally, a process is proposed that is promising for scale-up and optimization with regard to economic issues.