Coupled steam and oxidative reforming for hydrogen production in a novel membrane circulating fluidized-bed reformer

A novel circulating fluidized-bed membrane reactor employing a reactor-regenerator type of configuration is proposed for hydrogen production by the steam reforming of natural gas. The removal of hydrogen through hydrogen-permeable membranes pushes the equilibrium toward higher production of hydrogen. In the present paper, modeling studies are carried out on the reactor section of this configuration. Cases with and without hydrogen-selective membranes (cocurrent and countercurrent) are considered and compared. The model results show the great advantages associated with the breaking of the thermodynamic limitations coupled to the hydrodynamic limitations associated with the previous generations of bubbling fluidized-bed reformers. It is shown that autothermal operation can be achieved through simultaneous oxidative reforming, giving high hydrogen yields and productivities with low net consumption of energy.