Modeling and simulation of an industrial falling film reactor using the method of lines with adaptive mesh. Study case: Industrial sulfonation of tridecylbenzene

The method of lines with adaptive mesh was used to solve a falling film reactor model for the industrial sulfonation of tridecylbenzene. A model composed by three partial differential equations, three ordinary differential equations and several arithmetic ones was proposed. Using a discretization of 60 nodes in radial direction, the percentage of error respect to plant data in terms of exit liquid mean temperature and SO3 conversion was 0.03% and 1%, respectively. Temperature distribution in the liquid film aided to detect hot zones in the falling film near the entrance of the reactor, reaching an increase of ca. 36 K in the hottest point. The behavior of the reaction along the reactor was also studied based on the conversion profile and concentration distribution in the liquid film. The model allows performing a complete analysis of the reactor operation, making the model and its results a useful tool for the industry.