South African Journal of Chemical Engineering (Jan 2021)
Performance evaluation of hydrogen permeation through pd/cu membrane at different plasma system conditions
Abstract
The interest of hydrogen separation using palladium-based membranes has been raised due to their high permeability and selectivity. In this study, the performance of hydrogen permeation using dielectric barrier discharge (DBD) plasma in a microchannel plate reactor (MPR) was investigated. Pure hydrogen gas was injected into the MPR reactor at H2 flow rate of 0.1 L/min. The effect of plasma only, plasma-catalyst, plasma-heating, and the electrode gap distance (EGD) on the performance of H2 permeation through Pd-Cu membrane was experimentally analyzed. The results showed that these parameters have an important influence on hydrogen permeation through Pd-Cu membrane. Small amount of permeated hydrogen gas was observed in the sole DBD plasma experiments when plasma applied at ambient temperature. Furthermore, a significant enhancement of hydrogen permeation rate at high input power was registered in the plasma-catalyst experiment because of the plasma creates an increase in the surface gas temperature increased subsequently catalyst temperature which enhanced the catalytic material activity. The best hydrogen permeation rate was achieved in the plasma-heating experiment and electrode gap distance of 4.5 mm. Moreover, it was found that the electrode gap distance (EGD) has an important role in enhancing the hydrogen permeation under DBD plasma. Additionally, it was found that at large electrode gap distance (4.5 mm) has the long residence time which improved the hydrogen permeability and H2 permeation rate reach the maximum value of 102.7%. Also, it can be concluded that the DBD plasma should be used with catalyst and a suitable electrode gap distance.