Performance test of a bench-scale multi-tubular membrane reformer

Abstract

Apart from H 2 production, hydrogen membrane reforming is also an attractive process for CO 2 capture when integrated in a natural gas fired power plant. In this study, a bench-scale multi-tubular Pd membrane reactor which has a capacity of 8.5 Nm 3/h H 2 product, was used to carry out the methane steam reforming reaction at near-practical working conditions: 823 K and up to 35 bar(a). The maximum CH 4 conversion and H 2 production rate were respectively achieved as 73.4% and 1.3 Nm 3/h at a feed/permeate pressure of 35/5 bar(a). A typical pre-reformed mixture (PR) was used as feed gas in this work, and was found to be more efficient than CH 4/H 2O mixture that is normally adopted in the literature. The steam sweep exhibited a similar effect as N 2 sweep except at very low space velocity that revealed steam outperforming N 2. Stable performance was found both for the membranes and the membrane reactor under the challenging conditions for over 30 days, showing a great potential of hydrogen membrane reforming for H 2 production. However, membrane reforming is found to be less attractive for CO 2 capture due to the low CH 4 conversion and consequent low driving force for transmembrane hydrogen transport at the high permeate pressure typical for NGCC operation.