Radial mixing diffusion of hydrogen in a packed-bed type of palladium membrane reactor
Radial mixing diffusion of hydrogen in a packed-bed type of palladium membrane reactor
复制标题
填充床式钯膜反应器中氢气的径向混合扩散
DOI：
10.1021/ie00026a004
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发表时间：
1994
影响因子：
4.2
通讯作者：
K. Haraya
中科院分区：
文献类型：
--
作者：
N. Itoh;W. Xu;K. Haraya
以往的研究表明，管式填充床型钯膜反应器通过钯膜选择性分离反应过程中产生的氢气，可以显著促进环己烷的催化脱氢反应。在常压、473 K下，采用环形填充床钯膜反应器，考察了径向扩散对低流速含氢混合气体中氢分离的影响。采用理想扩散模型和径向扩散模型对填充床内氢浓度（分压）的轴向分布进行了实验测量和数学分析。理想流动模型不能很好地解释实验结果。径向扩散模型能较好地模拟钯膜反应器中氢分压沿床层沿着方向的分布。结果表明，由于氢透过钯膜，在填充床径向存在氢分压梯度。此外，还确定了低雷诺数下的佩克莱数，并可以用扩展的温范方程来解释。
A previous study has shown that a tubular packed-bed type of palladium membrane reactor can considerably promote the catalytic dehydrogenation reaction of cyclohexane by selectively separating hydrogen produced in the course of reaction through palladium membrane. Effects of radial diffusion on the hydrogen separation from a low-flow-rate gas mixture containing hydrogen was examined under atmospheric pressure at 473 K using an annular packed-bed type of palladium membrane reactor. The axial profiles of hydrogen concentration (partial pressure) in the packed bed were experimentally measured and mathematically analyzed using two flow models, ideal and radial diffusion models. The ideal flow model could not explain the experimental results very well. On the other hand, the radial diffusion model could successfully simulate the profiles of hydrogen partial pressure formed along the packed bed of palladium membrane reactor. It became clear that there exists a gradient of hydrogen partial pressure in the radial direction of the packed bed due to its permeation through palladium membrane. In addition, Peclet numbers at low Reynolds numbers were determined and were explainable by the extended Wen and Fan equation.