Reactions, hydrodynamics and mass transfer in micro-packed beds-Overview and new mass transfer data
Reactions, hydrodynamics and mass transfer in micro-packed beds-Overview and new mass transfer data
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DOI：
10.1016/j.cep.2016.09.016
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发表时间：
2016-12-01
影响因子：
4.3
通讯作者：
Larachi, Faical
中科院分区：
文献类型：
--
作者：
Faridkhou, Ali;Tourvieille, Jean-Noel;Larachi, Faical
对微填充床的研究进行了回顾，指出了其主要发现的主要贡献。微填充床中可忽略不计的传质阻力和温度梯度使得能够获得内在的动力学数据。小规模还可以为极端条件和危险材料的生产提供安全性。微填充床的流体动力学研究表明，更强的毛细管力会导致宏观和微填充床之间的流体动力学差异。此外，研究一致认为，活塞流的偏差很小。微填充床中的传质研究大多与动力学研究相结合，结果通常报告为总体传质系数比宏观尺度高两个数量级。在所审查的研究中，传质被认为是覆盖率最低的，因此对微填充床中的液-固传质系数（k(Ls)）进行了补充工作。实验在扩散限制范围内进行，并讨论了 k(LS) 值与宏观尺度相关性的对应关系。研究发现，在单相液体流动中，微观尺度 kLs 可以通过宏观尺度相关性来密切预测。宏观和微观尺度的比较表明，由于有限体积内固液相互作用较高且表面积与体积比较高，后者的体积传质系数较高。 (C) 2016 Elsevier B.V. 保留所有权利。
Studies on micro-packed beds were reviewed pointing out major contributions with their key findings. Negligible mass transfer resistance and temperature gradients in micro-packed beds enables access to intrinsic kinetic data. Small scales also provide safety for extreme conditions and production of hazardous materials. Hydrodynamic studies in micro-packed beds suggest that stronger capillary forces give rise to hydrodynamic differences between macro- and micro-packed beds. Also, studies reach consensus that deviations from plug flow are minimal. Mass transfer studies in micro-packed beds have been mostly coupled with kinetic studies and results are typically reported as overall mass transfer coefficients two orders of magnitude higher than those in macro-scale. Among the reviewed studies, mass transfer has been identified as the scarcest in coverage and therefore a complementary work was performed on liquid-solid mass transfer coefficients (k(Ls)) in micro-packed beds. Experiments were performed within the diffusion-limited regime and the correspondence of k(LS) values with macro-scale correlations was discussed. It was found that in single-phase liquid flow, micro-scale kLs is closely predicted by macro-scale correlations. Comparison between macro- and micro-scale showed that volumetric mass transfer coefficients are higher in the latter due to higher solid-liquid interactions in confined volumes and high surface-to-volume ratios. (C) 2016 Elsevier B.V. All rights reserved.