Hydrogen Permeation in Selected Systems

Light alkane (C2-C4) dehydrogenation was the reaction studied by Gryaznov and coworkers in their pioneering studies [2.1, 2.2]. In their dehydrogenation reaction studies, they used Pd or Pd-alloy dense membranes, which were 100 % selective towards hydrogen permeation. The choice of these membranes in many of the early studies is because they were commercially available at that time in a variety of compositions, and their metallic nature allows the construction of multitubular and other complex-shaped membrane reactor systems. Comprehensive review papers on Pd membrane reactors have been published by the same group [2.1, 2.2], and also by Shu et al [2.3]. 

Membrane separation is also used to separate hydrogen selectively from the rest of the reformate gases. Palladium membranes provide excellent permeation selectivity to hydrogen. A disadvantage is the low long-term stability of thin membranes in pressurized systems - the lowering of the amount of Pd being a prerequisite for low-... 

The feasibility of the palladium membrane system with an oxidation reaction on the permeation side and 1-butene dehydrogenation reaction on the reaction side in a membrane reactor has been successfully demonstrated. The palladium and its alloy membrane not only can withstand high temperature but also are selectively permeable to hydrogen... 

The generation of electrolytic hydrogen is achieved by selecting an MHR system in the electricity generation mode [72]. The two major safety aspects, higher operating temperatures and tritium permeation to the product gas, were evaluated and shown not to be a serious concern for the nuclear process heat plant [63]. 

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