Liquid-Liquid Extraction Technology 0610 4501 Liquid-Liquid Extraction Technology at Sulzer Chemtech Sulzer Chemtech, a member of the Sulzer Corporation, with headquarters in Winterthur, Switzerland, is active in the field of process engineering, employing 3’000 persons worldwide. Sulzer Chemtech is represented in all important industrial countries setting standards in the field of mass transfer and static mixing with its advanced and economical solutions. Sulzer Chemtech is organized into four business units, one of which is the Process Technology group. This business unit was formed in early 2009 following the acquisition of Kühni, a Swiss company with more than 75 years experience in innovative separation processes. Today, Sulzer Chemtech Process Technology is headquartered in Allschwil (Basel), Switzerland. We provide a unique and wide portfolio of separation and application technologies, amongst which liquid-liquid extraction. Working Principle Fields of Application Liquid-liquid extraction is an important the liquids are transported countercur- Liquid-liquid extraction is a complex sepa- separation technology, with a wide range rently. The viscosity and interfacial tension ration process. An additional component of applications in the modern process in- are additional important parameters. has to be introduced as extractant, which dustry. The extraction process is based on makes other subsequent separation steps In nearly all liquid-liquid extraction pro- different solubilities of components in two necessary. Therefore, liquid-liquid extrac- cesses one of the liquids is dispersed into immiscible, or partially miscible, liquids. tion is mostly used when separation of the second liquid in the form of droplets. The components that need to be recov- components by distillation is either un- The key for a high process performance ered are extracted from the feed stream economical, or even impossible. Some is an adapted droplet size and a uniform with the help of an extractant (often called examples are: hold-up profile throughout the column. solvent). Both liquids have to be thorough- This requires specially adapted equipment • Simultaneous separation of various ly contacted and subsequently separated and in-depth know-how about two phase components with widely differing boiling from each other again. To achieve high pu- liquid flows. points rities and yields, it is necessary to operate with multiple stages and with the liquids • Separation of high-boiling products or flowing countercurrently. pollutants which are present in only low concentrations For successful separation by extraction, all • Separation of components with similar components must meet certain specifica- boiling points or components forming tions. The main criteria for the extractant azeotropes are a favorable partition coefficient, a high selectivity and an easy separation from • Separation of mixtures with thermally the extracted product. The basic condi- sensitive components tions for the pair of liquids are a low mutual • Selective separation of single compo- solubility and a difference in density, which nents out of a multi-component mixture is the driving force for the motion of the • Separation of components from electro- droplets. In most multistage extractors, lytic solutions Our head offices in Allschwil, Switzerland 0611 4503-1 2 Liquid-Liquid Extraction Technology at Sulzer Chemtech Overview of Equipment Sulzer Chemtech, a member of the Sulzer Corporation, with headquarters in Winterthur, Switzerland, is active in the field of process Our liquid-liquid extraction is a technically sophisticated separation technology, offering you a solution where other tech- engineering, employing 3’000 persons worldwide. Sulzer Chemtech is represented in all important industrial countries setting standards nologies are uneconomical or even not feasible in the field of mass transfer and static mixing with its advanced and economical solutions. Sulzer Chemtech is organized into four business units, one of which is the Process Technology group. This business unit was formed in Extractors Classification Extractor Types early 2009 following the acquisition of Kühni, a Swiss company with more than 75 years experience in innovative separation processes. Today, Sulzer Chemtech Process Technology is headquartered in Allschwil (Basel), Switzerland. We provide a unique and wide portfolio The main task of any extractor is to create A wide range of equipment for liquid-liquid You can find our equipment in almost all of separation and application technologies, amongst which liquid-liquid extraction. optimal conditions for mass transfer be- extraction is available, which can be cat- industrial applications. Our portfolio is tween the two phases. This includes drop- egorized as follows: based on a number of modern, efficient let formation / dispersing, transport and • Extraction columns types of extractors. The core of this range Working Principle Fields of Application settling of the phases. Two types of dis- is the agitated Kühni column type ECR • Mixer-settlers Liquid-liquid extraction is an important the liquids are transported countercur- Liquid-liquid extraction is a complex sepa- persion are possible. The feed can be dis- with an extremely wide field of applica- • Centrifugal extractors separation technology, with a wide range rently. The viscosity and interfacial tension ration process. An additional component persed into the solvent, or be continuous tions, and the Sulzer packed column ECP. of applications in the modern process in- are additional important parameters. has to be introduced as extractant, which with the solvent dispersed into it. These The extraction columns, also referred to as Mixer-settler type extractors are available dustry. The extraction process is based on makes other subsequent separation steps two types often show a considerably dif- extraction towers, can be further differenti- if process reasons do not favor the use of In nearly all liquid-liquid extraction pro- different solubilities of components in two necessary. Therefore, liquid-liquid extrac- ferent behavior. Also, the type of contact ated into three groups: columns. cesses one of the liquids is dispersed into immiscible, or partially miscible, liquids. tion is mostly used when separation of between the two phases is an important, the second liquid in the form of droplets. • Static without energy input Column type extractors: The components that need to be recov- components by distillation is either un- equipment related aspect. In the case of The key for a high process performance • Agitated • Agitated Kühni column ECR ered are extracted from the feed stream economical, or even impossible. Some stage-wise contact, the liquids are com- is an adapted droplet size and a uniform with the help of an extractant (often called examples are: pletely separated from each other in every • Pulsed • Sulzer packed column ECP hold-up profile throughout the column. solvent). Both liquids have to be thorough- stage, whereas in the case of differential This requires specially adapted equipment • Simultaneous separation of various Mixer-settler type extractors: ly contacted and subsequently separated contact, the liquids are in continuous, and in-depth know-how about two phase components with widely differing boiling • Mixer-settler EMS from each other again. To achieve high pu- countercurrent contact. Both systems liquid flows. points rities and yields, it is necessary to operate have specific advantages affecting equip- • Mixer-settler column ECMS with multiple stages and with the liquids • Separation of high-boiling products or ment sizes and extraction efficiency. flowing countercurrently. pollutants which are present in only low concentrations For successful separation by extraction, all • Separation of components with similar components must meet certain specifica- boiling points or components forming tions. The main criteria for the extractant azeotropes are a favorable partition coefficient, a high selectivity and an easy separation from • Separation of mixtures with thermally the extracted product. The basic condi- sensitive components tions for the pair of liquids are a low mutual • Selective separation of single compo- solubility and a difference in density, which nents out of a multi-component mixture Sulzer extraction packing Installation of an industrial ECR type column on site is the driving force for the motion of the • Separation of components from electro- droplets. In most multistage extractors, lytic solutions Our head offices in Allschwil, Switzerland 0611 4503-1 2 3 Agitated Kühni Column ECR Our flexible, multipurpose extraction column Basic and Mechanical Design Advantages and Characteristics The agitated Kühni column is a well-prov- Based on its flexible design and our long- en, highly efficient extractor. Its main char- standing experience, the Kühni column acteristics are the agitated compartments, ECR has a range of advantages: arranged one on top of each other. The • Universal use concept is simple, yet, its hydrodynamic performance is outstanding. • High flexibility for varying process para- meters and physical properties Turbine Mixers and Partition • Reliable scale-up Plates • More than 30 theoretical stages in one single column Turbine agitators installed in each stage are responsible for the formation of the • Standard turndown 1 : 3 dispersion. They create a torus-shaped, • Column diameter: 30 mm - 3.5 m rotary flow pattern and also mix the liquid • Physical properties: