Kyriakides A., Voutetakis S., Papadopoulou S., Seferlis P., 2015, Optimization of a Membrane Reactor for Low Temperature Methane Steam Reforming, Chemical Engineering Transactions, 45, 703-708.
The main aim of this study is the optimization of a membrane reactor (MR) for H2 production via CH4 steam reforming (MSR). Reactions take place over a Ni-Pt/CeZnLa foam supported catalyst at operating temperature of 500 °C and pressure of 10 bar. A permeable membrane with Pd-Ru deposited on a ceramic dense support is used to selectively remove the produced H2 from the reaction zone. In this way, chemical equilibrium is shifted towards H2 production, thus enabling the achievement of a high CH4 conversion at relatively low temperature levels. A model-based optimization framework has been developed in order to calculate the optimal operating conditions for the highly interactive reactor system. A nonlinear, two-dimensional, and pseudo-homogeneous mathematical model of the membrane fixed-bed reactor validated using results from an experimental MR installed at the Process Systems Design and Implementation Laboratory (PSDI) of CPERI/CERTH is utilized in the optimization framework. The mathematical model consists of mass, energy and momentum balances considering both axial and radial gradients of temperature and concentration. The optimal steam to carbon ratio and sweep gas flow rate that minimize the overall CH4 utilization (i.e. reformed CH4 and equivalent CH4 for heating purposes) have been calculated for a range of H2 production rates. ?he optimal reactor design is also calculated for a given pure H2 production rate.
