Multistage Liquid Liquid Extraction (LLE) is a process where extraction steps are repeated in order to increase the recovery of a product. This process is required when, due to a small partition coefficient, the recovery in a single extraction step is insufficient.
In industrial applications, LLE is most often arranged with a “countercurrent scheme” (CC-LLE) that provides the smallest consumption of extractant. In this scheme, the aqueous raffinate from one stage is fed to a former stage as a feed while the organic phase is moved in the opposite direction. Hence, even if the recovery of product in each stage is small, the overall system can achieve a high level of recovery.
In other words, with multistage extraction, selectivity of the extraction and process yield are decoupled as the yield depends on the number of extraction stages used, thus providing greater freedom to the process developer.
This system address 3 key challenges typically encountered in developing multi-stage LLE: lack of information, lack of material and difficulty in scale up.
|Typical Internal Volume per Stage at Lab scale (ml)||25-100||150||100||2|
Below we report the extraction of acetone from water with toluene (this is a solvent system used in literature to benchmark Multistage extraction systems). We plot the overall acetone recovery vs. number of stages used. We report the experimental results and data obtained with ASPEN simulation assuming 100% extraction efficiency at each step.
There are two results to highlight:
René Lebl, Trevor Murray, Andrea Adamo, David Cantillo, C. Oliver Kappe, Continuous Flow Synthesis of Methyl Oximino Acetoacetate: Accessing Greener Purification Methods with Inline Liquid-Liquid Extraction and Membrane Separation Technology, ACS Sustainable Chem. Eng. Nov 2019.
Nopphon Weeranoppanant, Andrea Adamo, Galym Saparbaiuly, Eleanor Rose, Christian Fleury, Berthold Schenkel, and Klavs F. Jensen, Design of Multistage Counter-Current Liquid–Liquid Extraction for Small-Scale Applications Ind. Eng. Chem. Res. Apr 2017.
Yi Shen, Nopphon Weeranoppanant, Lisi Xie, Yue Chen, Marcella R. Lusardi, Joseph Imbrogno, Moungi G. Bawendi and Klavs F. Jensen, Multistage extraction platform for highly efficient and fully continuous purification of nanoparticles Nanoscale Mar 2017.
Maryam Peer, Nopphon Weeranoppanant, Andrea Adamo, Yanjie Zhang, and Klavs F. Jensen, Biphasic catalytic hydrogen peroxide oxidation of alcohols in flow: Scale up and extraction Org. Process Res. Dev. Aug 2016.
Contact us if you need more than 5 stages. Platforms can be easily connected together.
|Width||500 mm (19.7 inches)|
|Depth||400 mm (15.7 inches)|
|Height||155 mm (6.1 inches)|
|Total flow rate||0-10 ml/min|
|Separators||ETFE, PFA, FEP, PTFE|
|Pulsation dampener||ETFE, PFA|
|Interstage pumps||FFMK, PVDF|
|Ports||1/4-28 Flat bottom|