Liquid–liquid extraction for efficient synthesis and separation by utilizing micro spaces
Liquid–liquid extraction for efficient synthesis and separation by utilizing micro spaces
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DOI：
10.1016/j.ces.2008.05.017
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发表时间：
2008-08
影响因子：
4.7
通讯作者：
Y. Okubo;T. Maki;Nobuaki Aoki;Teng Hong Khoo;Yoshikage Ohmukai;K. Mae
中科院分区：
文献类型：
--
作者：
Y. Okubo;T. Maki;Nobuaki Aoki;Teng Hong Khoo;Yoshikage Ohmukai;K. Mae
利用微空间的特性，可以强化液液两相间的传质，提高萃取效率。本论文研究了Y型微通道接触流、分段流和乳化三种萃取操作。使用分段流的提取依赖于通过分子扩散的传质，并且其速率通过段塞内部产生的内循环流而增强。通过调节操作参数，如流速和流速比，可以精确地控制萃取速率。液-液两相分离可以瞬间实现。因此，包括液-液萃取然后两相分离的方法的连续操作预期是可能的。对于基于乳化的萃取，由于界面面积的显著增加，使得快速萃取成为可能。虽然萃取本身是快速的，但液-液分离可能需要很长时间，因为稳定乳液的聚结需要时间。它适用于强烈要求快速萃取的系统。通过将萃取操作结合起来，充分利用分段流或乳化与反应的特点，可以开发出先进的反应分离系统。
Enhancement of mass transfer between two phases and improvement of extraction efficiency are expected if features of micro spaces are adopted for a liquid–liquid two-phase process. In this work, three extraction operations, contact flow in a Y-shaped microchannel, segmented flow and emulsification, have been investigated. Extraction using segmented flow is dependent on mass transfer by molecular diffusion and its rate is enhanced by the internal circulation flow generated inside slugs. The extraction rate can be controlled precisely by adjusting operational parameters such as the flow rate and the flow rate ratio. Liquid–liquid two-phase separation can be achieved instantly. Thus, continuous operation of a process involving liquid–liquid extraction and then two-phase separation is expected to be possible. For extraction based on emulsification, rapid extraction is made possible owing to significant increase in the interfacial area. Though extraction itself is rapid, liquid–liquid separation may take a long time because coalescence of stable emulsions requires time. It is suitable for systems strongly requiring only rapid extraction. Advanced reaction–separation systems can be developed by combining the extraction operations, making full use of the characteristics of segmented flow or emulsification and the reaction.