Department of Chemical and Biochemical Engineering, Missouri University of Science and Technology, Rolla, MO 65409-1230, USA.
J Sep Sci. 2013 Jun;36(12):1913-24. doi: 10.1002/jssc.201300126.
A mathematical model is constructed and solved that could describe the dynamic behavior of the adsorption of a solute of interest in single and stratified columns packed with partially fractal porous adsorbent particles. The results show that a stratified column bed whose length is the same as that of a single column bed, provides larger breakthrough times and a higher dynamic utilization of the adsorptive capacity of the particles than those obtained from the single column bed, and the superior performance of the stratified bed becomes especially more important when the superficial velocity of the flowing fluid stream in the column is increased to accommodate increases in the system throughput. This occurs because the stratified column bed provides larger average external and intraparticle mass transfer and adsorption rates per unit length of packed column. It is also shown that increases in the total number of recursions of the fractal and the ratio of the radii between larger and smaller microspheres that make up the partially fractal particles, increase the intraparticle mass transfer and adsorption rates and lead to larger breakthrough times and dynamic utilization of the adsorptive capacity of the particles. The results of this work indicate that highly efficient adsorption separations could be realized through the use of a stratified column comprised from a practically reasonable number of sections packed with partially fractal porous adsorbent particles having reasonably large (i) total number of recursions of the fractal and (ii) ratio of the radii between larger and smaller microspheres from which the partially fractal particles are made from. It is important to mention here that the physical concepts and modeling approaches presented in this work could be, after a few modifications of the model, applied in studying the dynamic behavior of chemical catalysis and biocatalysis in reactor beds packed with partially fractal porous catalyst particles.
构建并求解了一个数学模型，该模型可以描述在填充部分分形多孔吸附剂颗粒的单柱和分层柱中吸附感兴趣的溶质的动态行为。结果表明，长度与单柱床相同的分层柱床比单柱床提供更大的穿透时间和更高的颗粒吸附容量的动态利用率，并且当柱中流动流体的表面速度增加以适应系统吞吐量的增加时，分层床的优越性能变得更加重要。这是因为分层柱床提供了更大的单位填充柱长度的外部和颗粒内传质和吸附速率。还表明，分形的总递归次数和构成部分分形颗粒的较大和较小微球之间的半径比的增加会增加颗粒内传质和吸附速率，并导致更大的穿透时间和颗粒吸附容量的动态利用率。这项工作的结果表明，可以通过使用由具有合理大（i）分形的总递归次数和（ii）较大和较小微球之间的半径比的部分分形多孔吸附剂颗粒组成的分层柱来实现高效的吸附分离。从部分分形颗粒制成。值得一提的是，本工作中提出的物理概念和建模方法在经过模型的一些修改后，可以应用于研究填充部分分形多孔催化剂颗粒的反应器床中化学催化和生物催化的动态行为。
