Modeling and Control of the Crude Atmospheric Unit in Khartoum Refinery

Moutaz M. Eldirderi, Salah Eldeen F. M. Hegazi

Abstract: The work undertaken, lead to a mathematical model of the distillation column that can separate multicomponent systems in Khartoum refinery. Software was developed and might be used for research and development as well as at the stage of starting - up and shut down periods. A case study taking Distillation Column Units (DCU) of Khartoum Refinery was studied and investigated. This work investigates the experimental data for the equilibrium of the Nile blend crude was determined. The equilibrium data were correlated (using short cut methods) and an equilibrium model was constructed. This model coupled with a multicomponent material balance was used for the determination of the number of theoretical stages, stage efficiency, and composition and temperature profiles. Three transfer functions around the condenser, the re boiler and the feed plate were determined. Software of MATLAB 7 was used to analyze the system stability, these were Nyquist diagram, Bode plot and Routh Hurwtz. The transfer functions of the reboiler, condenser, and feed plate were obtained. From the transfer functions created Nyquist diagrams, Bode plots, were converted from Laplace domain to Z domain, using MATLAB7 Software. A closed loop control strategy for the system was recommended.

Keywords: Equilibrium, Distillation, Matlab, Multi-components, Software, Condenser