Modeling and simulation of removal of sulfur component from oil in a fixed bed reactor in dynamic state

Author(s): Maryam Mirzaie, Amir Sarrafi, Majid Tahmoresi

Sulfur compounds are the most important pollutants in petroleum products and removing these compounds is a primary objective in the refining industries. In this study, the industrial unifiner reactor of Shiraz refinery for hydrodesulfurization of naphtha has been simulated in dynamic conditions. The proposed model, consisting of a set of algebraic and partial differential equations, is based on a heterogeneous two-dimensional unsteady state formulation. The equations discretized in finite difference formand solved with 4th order Rung Kutta method in steady state condition and in dynamic condition, implicit finite differencemethod that cuppeldwhit simple iteration method was used. Changes in concentration and temperature profiles obtained and discussed as a function of reactor axial and radial position and time. the dynamicmodelwas applied to predict the dynamic behavior of the reactor. To verify the proposed model, the simulation results have been compared to available data from industrial reactor of the Shiraz refinery.A good agreement has been found between the simulation results and industrial data.Asensitivity analysis has been carried out to evaluate the influence of several parameters on the process. Results of simulation showed that conversion decreased from0.9548 to 0.923 with increase in concentration of sulfur in the feed of reactor from 1500 ppm to 2000 ppm and at high temperature conversion decreased from 0.9548 to 0.91 because of coke formation on catalyst.

Share this