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The closures determining the interactions of particle−particle and gas−particle are very important for gas−solid flow. A three-dimensional two-fluid modeling approach with the kinetic theory of granular flow is used to simulate the hydrodynamic behaviors of a bubbling fluidized bed and a circulating fluidized bed. The influences of the coefficient of restitution and the drag model on the flow pattern are studied. The simulation results for bubbling beds are compared with the experimental results of Lin et al. It is found that the coefficient of restitution has strong influence on the flow pattern of the particle phase in bubbling beds. A relationship between the coefficient of restitution and the superficial inlet velocity is correlated. The effects of restitution coefficient on the distribution of solid phase in the circulating fluidized beds were also studied. In this case, the influence of the coefficient of restitution is weaker than for bubbling fluidized beds.

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A three-dimensional (3D) Eulerian two-fluid model with an in-house code was developed to simulate the gas-particle two-phase flow in the fluidized bed reactors. The CO 2 capture with Ca-based sorbents in the steam methane reforming (SMR) process was studied with such model combined with the reaction kinetics. The sorptionenhanced steam methane reforming (SE-SMR) process, i.e., the integration of the process of SMR and the adsorption of CO 2 , was carried out in a bubbling fluidized bed reactor. The very high production of hydrogen in SE-SMR was obtained compared with the standard SMR process. The hydrogen molar fraction in gas phase was near the equilibrium. The breakthrough of the sorbent and the variation of the composition in the breakthrough period were studied. The effects of inlet gas superficial velocity and steam-to-carbon ratio (mass ratio of steam to methane in the inlet gas phase) on the reactions were studied. The simulated results are in agreement with the experimental results presented by Johnsen et al. (2006a, Chem Eng Sci 61:1195-1202.