Palladium membranes represent a suitable alternative to obtain high purity hydrogen for industrial applications. The modeling of hydrogen permeation through composite membranes is important to understand gas separation systems. Here, experimental and calculated hydrogen flux data through composite palladium/alumina membranes were compared. A dense palladium film of 2.4 μm thick was deposited on a porous support and the produced composite membrane presented infinite hydrogen/nitrogen selectivity. Experimental molecular hydrogen flux at 100 kPa and 723 K was 0.1015 ± 0.0009 mol m⁻² s⁻¹. Calculated molecular hydrogen fluxes with the conventional permeation model, without considering external mass transfer and support resistances, were at least 5.7 times greater than experimental data. However, calculated hydrogen flux was only 6.7% lower than the experimental flux at 100 kPa and 723 K when external mass transfer and support resistances were included in the conventional permeation model. Thus, external mass transfer resistances and the permeation through the porous support should be considered for a suitable description of hydrogen fluxes through composite palladium membranes.

中文翻译：

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外部传质和支撑阻力对复合钯膜氢渗透的影响

钯膜是获得工业应用高纯度氢气的合适替代品。通过复合膜的氢气渗透建模对于理解气体分离系统很重要。在这里，通过复合钯/氧化铝膜的实验和计算的氢通量数据进行了比较。2.4 μm 厚的致密钯膜沉积在多孔载体上，制备的复合膜具有无限的氢/氮选择性。100 kPa 和 723 K 下的实验分子氢通量为 0.1015 ± 0.0009 mol m ^-2  s ^-1. 在不考虑外部传质和支撑阻力的情况下，使用传统渗透模型计算的分子氢通量至少比实验数据大 5.7 倍。然而，当外部传质和支撑阻力包含在常规渗透模型中时，计算出的氢通量仅比 100 kPa 和 723 K 下的实验通量低 6.7%。因此，应考虑外部传质阻力和通过多孔载体的渗透，以适当描述通过复合钯膜的氢通量。