Abstract
The coupling of steam and oxidative reforming of methane has been studied in a circulating fast fluidized bed membrane reactor (CFFBMR). The concept of oxygen distribution has been investigated by employing discrete injection points along the length of the reformer. The addition of oxygen is to supply the necessary heat required by the endothermic reforming reactions from oxidative reforming reactions. An external air membrane separation system is suggested to supply pure oxygen. A mathematical model is used for a systematic simulation in order to investigate the performance of the CFFBMR. Simulation results show that the staging distribution of oxygen and removal of hydrogen by the permselective membrane play an important role in the significant shift of the thermodynamic equilibrium and substantial enhancement of hydrogen yield. It has been shown that the discrete distribution of oxygen has a potential to eliminate the thermal runaway by mitigating the temperature along the length of the CFFBMR. The results indicate that the coupling of endothermic steam reforming and exothermic oxidative reforming reactions allows efficient energy integration without external supply of energy. The exit hydrogen yield shows a maximum value at which the oxygen to methane feed ratio (O/M) is optimal. The locus of maximum exit hydrogen yield is chosen for the sensitivity analysis. The influence of various reformer key parameters is investigated.