Solving Separation Problems using Liquid-Liquid Extraction (LLE)

Distillation may be the chemical process industries workhorse for separating the components of a liquid mixture. However, extraction comes to the forefront when separations are either difficult or impossible to economically handle by ordinary distillation.

1. Solving Separation Problems using Liquid-Liquid Extraction (LLE) KMPS Whitepaper Series

2. Why use Liquid-Liquid Extraction (LLE)? Distillation may be the chemical process industries workhorse for separating the components of a liquid mixture. However , extraction comes to the forefront when separations are either difficult or impossible to economically handle by ordinary distillation. Some key examples are : Removal of high boiling organics from dilute aqueous streams such as waste water or fermentation broths. Recovery of non-volatile components which are typically inorganic chemicals. Extraction of water soluble components from immiscible organic streams. Separation of multi-component mixtures, often utilizing fractional extraction technique. R 1 R 2 R 3 R 4 E 1 E 2 E 3 E 4 M 1 M 2 M 3 M 4 B A C F

3. Hierarchy of Separation Methods

4. Industries Using LLE Chemical Washing of acids/bases, polar compounds from organics Biochemical Processing Recovery of carboxylic acid from fermentation broths Effluent Treatment Recovery of phenol, DMF, DMAC Pharmaceuticals Recovery of active materials from fermentation broths Polymer Processing Recovery of caprolactam for nylon manufacture Separation of catalyst from reaction products Petroleum Lube oil quality improvement Separation of aromatics/ aliphatics (BTX) Food Separation of essential oils (flavors and fragrances) Metals Copper production Recovery of rare earth elements Inorganic Chemicals Purification of phosphoric acid Nuclear Purification of uranium

5. The Challenge of LLE Most process engineers and scientists have very little education or training in utilizing LLE technology. Therefore , often this technology is not even considered for a separation problem. Even when LLE is recognized as a viable technology, there is still the issue of knowing how to develop an optimal LLE solution and further, how to take this solution to design and implementation of the production process. Some of the key questions to be asked: How do I select an appropriate solvent for an LLE process? What preliminary data can be developed on the lab scale for determining feasibility? What type of equipment is commercially available for LLE and how do I determine which type is best for my application? What are the steps for developing an optimal LLE process? Can I design commercial scale equipment with a high level of confidence? KMPS maintains a pilot plant dedicated to extraction R & D and applications testing

6. The KMPS Solution KMPS is a world leader in LLE technology. We call upon 50+ years of experience in the design and supply of optimal LLE processes. In our pilot plant alone we have studied more than 200 different LLE processes. We have supplied more than 300 commercial extraction columns and systems. At KMPS we can help you to answer all of the questions shown above by offering the following: A broad level of experience and large database in LLE processes and equipment. Laboratory and pilot plant testing in our Andrew E. Karr Technology Center . We can supply pilot columns for on-site testing, in particular when chemical shipment is an issue. We can design and supply many different extraction devices including KARR®, SCHEIBEL®, RDC and packed columns as well as mixer-settlers. We select the best equipment for each process - not the other way around. Our engineers will evaluate multiple separation techniques for every separation process and provide our clients with the most cost effective solutions.

7. Recent LLE Success Stories A biotech company was looking to develop a process for the recovery of carboxylic acids from fermentation broth . Initial testing with an RDC extraction column (rotating internals) was unsuccessful due to emulsification. KMPS has proven that the reciprocating action in the KARR® Column is often the only acceptable method to handle these types of systems. After performing pilot plant tests , we were able to design a supply an optimal extraction system including the KARR® Column and two downstream distillation columns. The system was delivered as a modular system, started up under our direction and has been successfully operating for several years.

8. Recent LLE Success Stories A large petrochemical company was looking to recover organic acids from a wastewater steam using a solvent that was produced by this company. After generating liquid-liquid equilibrium data to demonstrate the feasibility of the process, a pilot plant test program was performed. The results from the testing provided the design criteria for the LLE column and a distillation column. A complete modular system was provided by KMPS which has been successfully operating since 2013.

9. Recent LLE Success Stories A company specializing in inorganic chemicals was looking to expand the capacity of an existing metal extraction process that used continuous mixer-settlers. Feed solution and solvent from the plant were shipped to our pilot plant where we tested and optimized the process in a SCHEIBEL® Column (rotating turbine agitators). A production column was designed and supplied with a process performance guarantee . This column has been successfully operating for the past 5 years, providing higher capacity and improved recovery .

10. Recent LLE Success Stories A chemical company in Asia was looking to recovery a high concentration of organic acid from an aqueous reaction mixture . However , the process involved an unfavorable density gradient. KMPS successfully tested the application in a SCHEIBEL® Column where the baffle arrangement minimizes the tendency towards back-mixing and efficiency loss during scale up. A large production column was supplied and started up successfully under supervision by KMPS.

11. Solving Separation Problems using Liquid-Liquid Extraction (LLE)