In-situ repair of composite palladium membranes with macro defects: A case study.

A new method was developed for repairing Pd/Al 2 O 3 membranes with macro defects without the need of disassembling the membrane from the module. In order to target and fill the membrane defect automatically with solid particles, a TiO 2 powder was firstly tested by flowing high-pressure nitrogen as a carrier gas, followed by a heat treatment. A filter cake was found on the membrane defect but still porous. A glass powder was selected instead of TiO 2 , and the membrane defect was successfully sealed by glazing. The in-situ repair of a waste commercial Pd/Al 2 O 3 membrane separator was carried out with the glass powder, and the hydrogen flux and H 2 /N 2 selectivity of the membrane separator at 450 °C under 100 kPa reached 12.6 m3m−2h−1 and 1600, respectively. [Display omitted] • Pd/Al 2 O 3 membrane with macro defect can be repaired without membrane disassembling. • Solid particles can automatically fill and sinter on the membrane defect under nitrogen flowing. • A Li–B–Si–O glass powder can glaze and seal the membrane defect. • A waste commercial membrane separator showed high selectivity after repair. [ABSTRACT FROM AUTHOR]