SIMULATION OF METHANE REFORMING IN A FLUIDIZED BED REACTOR USING CFD

Abstract

A two dimensional (2D) transient simulation is carried out to simulate oxidative reforming of methane in a fluidized bed reactor for hydrogen production using the computational fluid dynamics software FLUENT 14.5. The two fluid approach along with equations for species transport is used to model the reactor. Combustion, steam reforming, dry reforming and shift reactions are incorporated in the reaction model and laminar finite rate model available in Fluent is used to model the reactions. Gidaspow drag model is used to model the interactions occurring between gas and solid phase in the reactor. The results have been validated again simulations done previously. The results show that model can satisfactorily represent the reforming of methane in a fluidized bed reactor. Hydrodynamics of the fluidized bed is also studied. The product gases mainly consists of Syngas and unreacted gases. The effect of carbon dioxide addition to the feed on hydrogen production has been studied and it was found to increase the hydrogen production. Increase in the feed temperature was found to increase the hydrogen production by it also increases the operating costs. Problem of hot spot formation was also found within the reactor. As the space velocity was increased the methane conversion and hydrogen production were found to decrease. Increasing the content of oxygen in the feed increased the conversion of methane . It was found to increase the hydrogen production and then reduce it after a certain ratio