Hydrogen Membrane Technologies and Application in Fuel Processing

Hydrogen Membrane Technologies and Application in Fuel Processing 

Hydrogen and Syngas Production and Purification Technologies, Edited by Ke Liu, Chunshan Song and Velu Subramani 

When selecting between membrane and PSA purification processes, it is important to consider scale. Practice has shown that PSA scales up economically and for large stationary applications (e.g., petroleum refining, petrochemical production, coal gasification), this may be the best choice. By the same reasoning, PSA usually does not scale down economically, and here membrane-based processes may be strongly favored. Also, membrane processes are more likely to be selected for applications wherein the platform is moving or otherwise subjected to shock and vibration that would likely have detrimental effects on PSA adsorbent beds. 

Yet another potential advantage of membrane purification processes over PSA is that membrane processes are usually more easily controlled. As mentioned above, they are continuous throughput operations as opposed to cyclic, multibed operations (characterized by PSA). Assuming the feed stream composition does not vary too much in composition, control of the membrane process may be as simple as controlling the membrane operating temperature, feed pressure, and permeate pressure. 

This section will provide an overview of the principles of hydrogen separation and purification using membranes. More detailed discussions of the theory governing membrane separation processes can be found elsewhere.1 

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Chapter 8 Hydrogen Membrane Technologies and Application in Fuel Processing... 

Although the mixed conduction is detrimental to fuel cell application, the high electronic conductivity of doped ceria in low p02 conditions can be exploited in hydrogen separation membrane technology. The chemical, thermal expansion and processing compatibilities of the two oxides in the composite make pervoskite-ceria combination suitable for the mixed conducting membrane application. 

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