Evaluation of silica membrane reactor performance for hydrogen production via methanol steam reforming: Modeling study

The aim of this work is to analyze the potential application of microporous silica membrane reactor carrying out methanol steam reforming reaction for hydrogen production. As a further study, a comparison with dense Pd-Ag membrane reactor and a traditional reactor, working at the same operating conditions of silica membrane reactor, is realized. To this purpose and as a first approach, a 1-dimensional isothermal numerical model was developed and its validation was realized by comparing the theoretical results with experimental data. In particular for silica MR, scientific literature experimental data were used, while both dense Pd-Ag membrane reactor and traditional reactor models were validated by our experimental data. In all three cases, a good agreement between modeling results and experimental data was found. So, the model was used for studying the effect of some important operating parameters (temperature, pressure and GHSV) on the performance of silica membrane reactor in terms of methanol conversion and hydrogen recovery. The same study was performed for both dense Pd-Ag membrane and traditional reactors. The modeling analyses showed that the silica membrane reactor presents comparable performance to the dense membrane reactor in terms of methanol conversion operating at low temperature (493 K) and high GHSV (more than 2000 h(-1)). Moreover, in order to improve the performance of silica MR, as an example different H-2/N-2 ideal selectivities were also investigated. This analysis indicated that the silica membrane reactor presents acceptable performance with respect to the dense Pd-Ag membrane reactor when the H-2/N-2 ideal selectivity is higher than 100 and hydrogen permeance is in the range: 1 x 10(-7)-5 x 10(-7) mol/m(2) Pa s. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.