Mathematical Model of a Falling Film Reactor for Methyl Ester Sulfonation

Abstract

Methyl ester sulfonation with sulfur trioxide derived from oleum is possible under special conditions on a pilot plant scale. Quantum chemical calculations were used to study the relative stability between intermediates in the proposed mechanism. In this report an analysis of a mathematical model for a falling film sulfonation reactor is presented. It aims to estimate the temperature and conversion profiles of the thin film. The model treats the heat released and the trioxide sulfur dissolution assuming that the film theory is applicable. The temperature and concentration gradients can exist across the film during the chemical reaction. The equations were solved using finite differences. The most important data obtained by the mathematical model for a subsequent correlation with the properties of the reagents and product are the conversion, the density and viscosity of the sulfonic product. The results indicate an increase in the axial temperature of the liquid film and the conversion from the top reactor in accordance with the experimental results. It considers that at the upper section of the reactor the reaction is controlled by means of mass transfer due to gas phase turbulence. A mild conversion on the reactor bottom means that the liquid phase controls the mass transfer due to the amounts of sulfur trioxide transferred into the film which produces changes in the film composition.