Investigation of Multistage Circulating Fast Fluidized Bed Membrane Reformers for Production of Ultraclean Hydrogen and Syngas

A rigorous mathematical model is implemented to simulate multistage circulating fast fluidized bed membrane reformers (CFFBMRs) for production of ultraclean hydrogen and a high-grade syngas. Discrete physically well-mixed catalysts are employed in this study. It has been shown that enhancement of the water-gas shift reaction (WGS) by addition of CO in the feed coupled with the heat release from the partial oxidation reactions substantially improved the total H-2 yield by 27.60% in the first CFFBMR1. At the best operating conditions, it was found that the total H-2 yield is significantly increased by 48.75% in the first CFFBMR1 and by 59.66% in the second CFFBMR2. The simulation results show that CO2 concentration can be reduced by 96.39% to a very low level. The results also reveal that the heat integration and energy saving can be realized through coupling endothermic and exothermic reactions reinforced by catalyst patterns.