Conversion-temperature diagram for a palladium membrane reactor. Analysis of an endothermic reaction: Methane steam reforming

An analysis of the conversion-temperature diagram for methane steam reformi ng is presented. A mathematical model of a membrane reactor (MR) containing a Pd-based membrane with ideal behavior was' developed to calculate the te mperature and species profiles. The comparison of annular and tubular confi gurations showed different MR performance because of thermal effects. The e quilibrium of the MR system was calculated, starting from the method of "re actors in series". The equilibrium curve of a MR was calculated as a functi on of the sweep factor (I), defined as the ratio of the sweep gas and metha ne feed Row rates. The existence region for a MR was defined as a function of I and is delimited by the adiabatic, isothermal, and equilibrium curves. Once I, the feed molar ratio, and the oven temperature were defined, the r eaction paths of ah MRs fell within the existence region. This was observed for various values of reaction rates, membrane thicknesses, flow rates, ov erall heat transfer coefficients, and geometric parameters. The existence r egion of a MR is, therefore, an extension of that in a traditional reactor, achieving better performance with increased methane conversion.