Experimental demonstration of the reverse flow catalytic membrane reactor concept for energy efficient syngas production. Part 2: Model development

In this contribution the technical feasibility of the reverse flow catalytic membrane reactor (RFCMR) concept with porous membranes for energy efficient syngas production is investigated. In earlier work an experimental proof of principle was already provided [Smit, J., Bekink, G.J., van Sint Annaland, M., Kuipers, J. A.M., 2005a. A reverse flow catalytic membrane reactor for the production of syngas: an experimental study. International Journal of Chemical Reactor Engineering 3 (A12)], but compensatory heating was required and problems related to the mechanical strength of the powder-based YsZ catalyst and the steel filter were reported. Therefore, in Part 1 the performance of a Rh-Pt/Al2O3 catalyst with improved mechanical strength and porous Al2O3 membranes with excellent temperature resistance was tested in an isothermal membrane reactor. For this purpose a novel sealing technique was developed that could withstand sufficiently high pressure differences and temperatures. Very high syngas selectivities close to the thermodynamic equilibrium could be achieved for a considerable period of time without any increase in pressure drop and without any decrease in syngas selectivity. Using the Rh–Pt/Al2O3 catalyst, several experiments were performed in a RFCMR demonstration unit and the influence of different operating conditions and design parameters on the reactor behaviour was investigated. It is shown that very high syngas selectivities (up to 95%) can be achieved with a maximal on-stream time of 12 h, without using any compensatory heating and despite inevitable radial heat losses. In Part 2 a reactor model is discussed that can well describe the experimental results presented in this part.