(132c) Computational Modelling of Dimethyl Ether (DME) Steam Reforming in a Dual Fluidized Bed System

DME has attracted attentions as a potential source of hydrogen for fuel cells. This study presents a theoretical investigation of the catalytic steam reforming of dimethyl ether (DME) for the production of hydrogen in the riser section of a dual fluidized bed (DFB) system. The DFB has the advantages of sustainable operation while regenerating the catalysts within the closed loop system. A two-phase (Eulerian-Eulerian) model was solved in CFD software (ANSYS FLUENT) to simulate the reactor flow hydrodynamics, heat transfer and reactions in three dimensional coordinates. A sub-model for the reactions and kinetics was developed and incorporated in the model as user defined function (UDF). The kinetic parameters for the DME steam reforming and the associated methanol reforming and water gas shift reactions were obtained from the experimental data reported by Feng et al., (2009) and Yan et al., (2014) with bi-functional catalyst CuO/ZnO/Al₂O₃ -ZSM-5. The effect of steam and catalysts to DME ratio, reactor temperature and space velocity on the DME conversion and product gas composition were investigated. The results have shown strong dependence of the DME conversion on the reactor operating temperature with the maximum hydrogen yield and 100% DME conversion obtained at the temperature >300 °C. The parametric analysis have shown good match between the model predictions and the reported experimental data, thus demonstrating the great potential of the proposed model for optimization and future development of the proposed process to industrial scale applications. 

Feng, D., Wang, Y., Wang, D., & Wang, J. (2009). Steam reforming of dimethyl ether over CuO–ZnO–Al2O3–ZrO2+ZSM-5: A kinetic study. Chemical Engineering Journal, 146(3), 477–485. doi:10.1016/j.cej.2008.11.005

Yan, C.-F., Ye, W., Guo, C.-Q., Huang, S.-L., Li, W.-B., & Luo, W.-M. (2014). Numerical simulation and experimental study of hydrogen production from dimethyl ether steam reforming in a micro-reactor. International Journal of Hydrogen Energy, 4–11. doi:10.1016/j.ijhydene.2014.02.133