(251b) Reformer Performance for Co-Current and Counter Current Flow Mode

A model for a methane steam reformer is presented. Endothermic steam reforming reaction is coupled with burner flue gases. Steam reformer is modeled as a pseudo homogeneous reactor. Concentration and temperature dependence of viscosity of gas mixture is incorporated in both process gas and flue gas for better accuracy. Gas is assumed to be an ideal gas. Wall heat transfer coefficient is modeled using suitable correlation. Concentric cylindrical geometry is considered for reactor where steam reforming takes place at inner tube and flue gas flows inside the annulus. Co-current and counter current mode of flow arrangement for fuel gas and process gas is considered separately. Resulting dynamic model equations are solved numerically for each flow arrangement under different operating parameters. From simulation results, comparison between two cases is made based on heat recovery, methane conversion, hydrogen to carbon monoxide ratio and maximum wall temperature. Dynamic effect of variation of operating parameters is simulated to obtain better insight for best control.