Reactor Configuration and Concentration Polarization in Methane Steam Reforming by a Membrane Reactor with a Highly Hydrogen-Permeable Membrane

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• 作者：Nobuhiko Mori ; Toshiyuki Nakamura ; Ken-ichi Noda ; Osamu Sakai ; Akira Takahashi ; Naoyuki Ogawa ; Hitoshi Sakai ; Yuji Iwamoto ; Tadashi Hattori
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2007
• 出版时间：March 28, 2007
• 年：2007
• 卷：46
• 期：7
• 页码：1952 - 1958
• 全文大小：167K
• 年卷期：v.46,no.7(March 28, 2007)
• ISSN：1520-5045

文摘

To examine the effect of so-called "concentration polarization" on the performance of a membrane reactorwith a highly hydrogen-permeable membrane, methane steam reforming was conducted, using a Pd/Agmembrane with a thickness of a few micrometers. First, the relation between the methane conversion and thehydrogen recovery was experimentally examined, and the relation was compared with that predicted by arather simple simulation that assumes the instant achievement of equilibrium. When the hydrogen recoverywas smallest, the experimental results agreed well with the simulation results. With increasing reaction pressure,the experimental methane conversion became lower than the simulated conversion. These results suggest thatthe reaction is limited by reduced hydrogen removal, because of the concentration polarization. The influenceof concentration polarization was confirmed by the comparison of the experimental results of hydrogenpermeation from a mixture of H₂ and N₂ with the simulation results based on the plug-flow model. It thenwas experimentally attempted to reduce the concentration polarization by changing the configuration of thereactor. The methane conversion was successfully improved using reactors that had narrower inner diametersand baffle plates, probably because of the reduction in concentration polarization. It was concluded that thereactor configuration was quite essential to make the best use of a membrane reactor with a highly permeablemembrane.