title: Performance and Long-Term Stability of Pd/PSS and Pd/Al2O3 Membranes for Hydrogen Separation.
abstract: The present work is focused on the investigation of the performance and long-term stability of two composite palladium membranes under different operating conditions. One membrane (Pd/porous stainless steel (PSS)) is characterized by a ~10 µm-thick palladium layer on a porous stainless steel substrate, which is pretreated by means of surface modification and oxidation; the other membrane (Pd/Al2O3) is constituted by a ~7 µm-thick palladium layer on an asymmetric microporous Al2O3 substrate. The operating temperature and pressure ranges, used for studying the performance of these two kinds of membranes, are 350-450 °C and 200-800 kPa, respectively. The H2 permeances and the H2/N2 selectivities of both membranes were investigated and compared with literature data. At 400 °C and 200 kPa as pressure difference, Pd/PSS and Pd/Al2O3 membranes exhibited an H2/N2 ideal selectivity equal to 11700 and 6200, respectively, showing stability for 600 h. Thereafter, H2/N2 selectivity of both membranes progressively decreased and after around 2000 h, dropped dramatically to 55 and 310 for the Pd/PSS and Pd/Al2O3 membranes, respectively. As evidenced by Scanning Electron Microscope (SEM) analyses, the pinholes appear on the whole surface of the Pd/PSS membrane and this is probably due to release of sulphur from the graphite seal rings.
authors: Institute on Membrane Technology of Italian National Research Council (ITM-CNR), c/o University of Calabria, Cubo 17/C, Rende (CS) 87036, Italy. s.liguori@itm.cnr.it.
authors: Simona
authors: S
authors: Liguori
authors: Institute on Membrane Technology of Italian National Research Council (ITM-CNR), c/o University of Calabria, Cubo 17/C, Rende (CS) 87036, Italy. a.iulianelli@itm.cnr.it.
authors: Adolfo
authors: A
authors: Iulianelli
authors: Chemistry and Chemical Technologies Department, University of Calabria, Cubo 15/D, Via P. Bucci, Rende (CS) 87036, Italy. dalena.ch@gmail.com.
authors: Francesco
authors: F
authors: Dalena
authors: RSE S.p.A., Via Rubattino 54, Milano (MI) 20134, Italy. pietro.pinacci@rse-web.it.
authors: Pietro
authors: P
authors: Pinacci
authors: RSE S.p.A., Via Rubattino 54, Milano (MI) 20134, Italy. francesca.drago@rse-web.it.
authors: Francesca
authors: F
authors: Drago
authors: RSE S.p.A., Via Rubattino 54, Milano (MI) 20134, Italy. maria.broglia@rse-web.it.
authors: Maria
authors: M
authors: Broglia
authors: State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry & Chemical Engineering, Nanjing University of Technology, Xin-Mo-Fan Road 5, Nanjing 210009, China. huangy@njut.edu.cn.
authors: Yan
authors: Y
authors: Huang
authors: Institute on Membrane Technology of Italian National Research Council (ITM-CNR), c/o University of Calabria, Cubo 17/C, Rende (CS) 87036, Italy. a.basile@itm.cnr.it.
authors: Angelo
authors: A
authors: Basile