Repair of palladium membrane modules by metallic diffusion bonding

• Inter-metallic diffusion offers a method to repair membrane defects.
• A procedure to repair membrane defects is developed.
• A repair permeation factor is introduced and its calculation method is derived.
• Repair factor is influenced by repair patch size and module hydrodynamics.
• Defects in two membrane modules have been successfully repaired.

Thin palladium membranes are easy to form defects during the preparation and application processes. The inter-metallic diffusion offers a method to repair large membrane defects such as wrinkles and cracks by pasting a membrane patch on the defect area. A repair procedure based on the inter-metallic diffusion bonding is developed. A repair permeation factor is introduced to denote the influence of the repair on membrane module performance. The repair factor is not only a function of the membrane repair patch size, but also the flow hydrodynamics of the membrane module and the position of the repair patch on the membrane module. Repair of the defects on two membrane modules has been successfully demonstrated. The integrity of the modules after repair is confirmed. The measured repair permeation factors are very close to those predicted ones.