SIMULATION OF TRICKLE BED REACTOR

Abstract

Hydrodesuffurization has assumed great importance in hydrocarbon industry. For the simulation of a trickle bed reactor, it is necessary to establish the model that best represents the reactor behaviour_ In most cases mathematical models are too involved mathematically and consist of non-linear ordinary or partial differential equations, which cannot be solved analytically. The present report pertains to the simulation of an industrial trickle bed hydrodesulfurization reactor. Dibenzothiophene is assumed as the major sulfur component present in the diesel fluids (liquid phase), and is hydrodesulfurized over CoO-Mo03/yA1203 catalyst bed in trickle flow regime. One-dimensional pseudo homogeneous model and one-dimensional heterogeneous model have been developed to describe the reactor behavior and its performance. The models do not account for the axial or radial dispersion as is the case normally found in the industrial trickle bed reactors. The one-dimensional homogeneous model equations have been solved using Runge-Kutta (fourth order) method. The one-dimensional heterogeneous model equations have been solved using orthogonal collocation technique coupled with broyden's method. Simulation of the models gives the variation of temperature and conversion along the bed depth and incorporates the concentration gradient inside the catalyst pores. The simulated models can be used to determine the operating parameter and to predict the performance of an industrial reactor.