A multichannel palladium (Pd) membrane system in association with flow bypass is designed for hydrogen separation with high recovery, and the mass transfer phenomena in the system are simulated by developing a computational fluid dynamics (CFD) model. Two Pd membranes are installed in the system. The predictions suggest that the H2recovery (HR) can be substantially improved by the bypass. The higher the feed gas Reynolds number, the more pronounced the improvement of H2recovery by the bypass. The HR by the first membrane is independent of the bypass ratio (BR), revealing that the enhancement of HR is completely contributed by the second membrane. An increase in H2/CO2molar ratio in the feed gas reduces HR, but raises the H2permeation rate. The maximum HR by the second membrane always develops at the feed gas Reynolds number (Rer,M1) of 500, regardless of bypass ratio. This reveals that the aforementioned Reynolds number is an appropriate condition for H2separation in the designed membrane system. Based on the HR in the absence of flow bypass (i.e., BR = 0), the higher the Rer,M1, the larger the intensification of H2permeation. A contour map and a correlation from regression analysis in terms of Rer,M1and BR are established. Under a desired H2recovery, the combination of Rer,M1and BR can be suggested to provide flexible operation for H2separation in the membrane system.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment