Hydrogen permeation substrate effect

The effect of the substrate on the hydrogen permeation through the composite membrane can be evaluated by the substrate influence factor, defined by the ratio of the pressure drop across the substrate to the total pressure difference across the composite membrane ... 

Figure 4.4 Hydrogen permeation flux through Pd/Al203 composite hollow fiber membranes as a function of temperature for substrates with different effective porosities. Reproduced from [15]. With permission from Elsevier.

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