Computational Study of Staged Membrane Reactor Configurations for Methane Steam Reforming: II. Effect of Number of Stages and Catalyst Amount

The present work complements part I of this article and completes a computational analysis of the performances of staged membrane reactors for methane steam reforming. The influence of the number of stages and catalyst amount is investigated by comparing the methane conversion and hydrogen recovery yield achieved by an equisized-staged reactor to those of an equivalent conventional membrane reactor for different furnace temperatures and flow configurations (co- and counter-current). The most relevant result is that the proposed configuration with a sufficiently high number of stages and a significantly smaller catalyst amount (up to 70% lower) can achieve performances very close to the ones of the conventional unit in all the operating conditions considered. This is equivalent to say that the staged configuration can compensate and in fact substitute a significant part of the catalyst mass of a conventional membrane reactor. To help the interpretation of these results, stage-by-stage temperature and flux profiles are examined in detail. Then, the quantification of the performance losses with respect to the conventional reactor is carried out by evaluating the catalyst amount possibly saved and furnace temperature reduction. (C) 2009 American Institute of Chemical Engineers AIChE J, 56: 259-267, 2010