Feasibility study of a novel membrane reactor for syngas production: Part 2: Adiabatic reactor simulations

To investigate the adiabatic behaviour of a novel Reverse Flow Catalytic Membrane Reactor with perovskite membranes, detailed reactor simulations were performed with an experimentally determined O2 permeation expression (Part 1). Simulation results obtained with the High Switching Frequency Model showed that when the activation energy was not accounted for in the O2 permeation expression, stationary reactor operation with high syngas selectivities can be achieved. However, these simulations also revealed that the local production rate of reaction heat changes enormously along the membrane. This caused severe temperature excursions when the activation energy was accounted for, which would be detrimental for the chemical and mechanical stability of the perovskite membrane, and no stable reactor operation could be achieved. To avoid these problems, the use of a porous support on the air side of the membrane to limit the O2 permeation flux was investigated. With HSFM simulations it was demonstrated that the local O2 permeation flux can indeed be moderated and stationary axial temperature profiles could be obtained. To demonstrate that the RFCMR with perovskite membranes can also be operated dynamically and that high quality syngas can be produced in an energy efficient way, simulations with the Dynamic Model were performed. Indeed very high syngas selectivities could be achieved, higher than typically encountered in current industrial practice.