Evaluation of Optimum Design Parameters and Operating Conditions of Axial- andRadial-Flow Tubular Naphtha Reforming Reactors, Using the Differential EvolutionMethod, Considering Catalyst Deactivation

摘要

In this study, a new flow pattern (radial-flow) in a tubuiar reactor is proposed for the naphtha reforming process. The operating conditions of axial-flow and radial-flow tubuiar packed-bed reactors have been optimized by the differential evolution (DE) method. The DE optimization method has been applied to maximize hydrogen and aromatic yields in the steady-state and dynamic conditions. Some parameters, such as total pressure, the hydrogen mole fraction in the recycled stream, the length per diameter of the reactor, and the mass distributions of the catalysts, have been optimized for the steady-state conditions. Moreover, the inlet temperature of the gas at the entrance of each reactor is optimized for the unsteady-state condition to compensate for the effect of catalyst deactivation. A set of coupled partial differential equations are solved by the orthogonal collocation method. The results demonstrate that, by utilizing the optimization technique and alternating the flow pattern in conventional catalytic reformers, the aromatic and hydrogen production rates increase 3.01% and 11.50%, which can approximately satisfy the increasing demand of hydrogen and high-octane gasoline in refineries.