Comparative analysis of different catalytic baskets for dual-bed catalytic reactor based on CFD simulations

Catalytic baskets used to support catalyst beds can have different designs. For industrial practice, reactors with axial and radial gas flow direction through the catalyst bed are commonly used. Based on CFD simulations, the influence of the tail gas distribution in a dual-bed catalytic reactor on the linear gas flow velocity and pressure drop across the catalyst bed was analysed. CFD simulations were performed for the reactor's use in a pilot nitric acid plant for axial-radial and radial catalytic basket designs. The calculation results indicated a significant influence of the basket design on the linear gas flow velocity profile and pressure drop distribution in a dual-bed catalytic reactor. The most advantageous solution was the coaxial arrangement of the catalyst beds without separating them with a space, which can affect the reliability of the reactor. The lowest linear flow velocity and gas flow resistance values in a dual-bed catalytic reactor were obtained for the mixed axial and radial gas flow through the catalysts beds, separated only with a porous baffle.