Numerical Investigation of Sorption Enhanced Steam Methane Reforming Process Using Computational Fluid Dynamics Eulerian−Eulerian Code

Abstract

This paper highlights the use of a fluidized bed reactor of 10 cm i.d. for producing hydrogen by sorption-enhanced steam methane reforming (SE-SMR). The model used for the hydrodynamic behavior of the bed is Eulerian−Eulerian. The kinetics of the steam methane reforming, water−gas shift, and carbonation reactions are based on literature values. Intra- and extraparticle mass transfer effects are considered together with the kinetics in the chemical models. The bed is composed of an Ni catalyst and calcined dolomite. A static bed height of 20 cm is investigated. A volume ratio of dolomite/catalyst is varied from 0−5 during the simulation. Dry hydrogen mole fraction of >0.93 is predicted for temperatures of 900 K and a superficial gas velocity of 0.3 m/s with a dolomite/catalyst ratio >2. Furthermore, the bubble formation in the fluidized bed influence product yields and product oscillations are observed. Another important aspect is that when the dolomite/catalyst ratio is higher than 2 the necessary heat for the reforming endothermic reaction can be almost entirely supplied by the exothermic reaction of carbonation.