Modeling of autothermal reforming of methane in a fluidized bed reactor with perovskite membranes

The performance of perovskite membrane-assisted fluidized bed reactors for ultra-high purity hydrogen production through autothermal reforming of methane has been investigated using numerical simulations. Two different three-phase phenomenological models have been developed differing in their description of the mass transfer between the membranes and the emulsion, cloud and bubble phases, where the parameters in the oxygen permeation flux expression were determined from new experimental data. The calculation of the required oxygen-to-carbon ratio is based on overall enthalpy balance. The reactor performance without and with O₂ permeable perovskite membranes have been investigated and compared. The two models of perovskite membrane-assisted fluidized bed reactors produce basically the same results, indicating that the external mass transfer from the membranes to the bulk of the fluidized bed is not rate limiting, but clearly show that the fluidized bed membrane reactor can largely outperform ordinary fluidized bed reactors for the autothermal reforming of methane. It has been demonstrated that with perovskite membrane-assisted fluidized bed reactors autothermal operation with a high CH₄ conversion and H₂ yield can be achieved with a relatively small catalyst inventory.