Liquid-Liquid Extraction Equipment and Chemical Separation Solutions
Koch Modular goes beyond designing and constructing liquid-liquid extraction columns. We continue the relationship with our customers after installation and startup. Koch Modular provides replacement parts, repair services and troubleshooting assistance for all types of extraction columns. Our team consists of professional, skilled, and highly qualified technicians and engineers who can provide on-site mechanical and process related support.
In addition to distillation, the application of liquid-liquid extraction is recognized as a powerful separation method in the chemical industry. (see figure on the right).
Reasons to use liquid-liquid extraction:
- To break azeotropes
- Compounds are sensitive to heat or non-volatile
- The liquid-liquid extraction process involves a complex distillation sequence
- The distillation project has prohibitive energy requirements
- Distillation is not enough to separate solvents
The general rule: Extraction can be avoided if it is more economical to separate solvents via distillation. Liquid-liquid extraction methods, however, are needed when factors such as low volatility, heat sensitive materials, high operating costs/investments, complex process sequences are involved.
Next, it is important to consider the solvent recovery aspects early in the project since they can affect the overall process economics. By looking at the sample extraction process below, you can see that approximately 3% of the operating cost is incurred in the extractor and the remaining 97% in solvent recovery. In most cases, a majority of the capital cost is incurred downstream of the extraction column.
Common Liquid-Liquid Extraction Applications
- Washing polar compounds, acids, and bases from organics
- Recovering acrylic acids
- Recovering carboxylic acids from fermentation broths or other biomass
- Recovering oil from algae broths
- Recovering active materials from fermentation broths
- Purifying vitamin products
- Recovering phenol, DMF, DMAC
- Recovering acetic acid from dilute solutions
- Recovering caprolactam for nylon-manufactured products
- Separating catalyst from reaction products
- Improving overall lube oil quality
- Separating aromatics/aliphatics (BTX)
- Separating olefins/parafins
- Separating structural isomers
- Decaffeination of tea and coffee
- Separating essential oils in the flavors and fragrances industries
Complete System Design
In addition to the extraction column, the downstream distillation column design is also an important aspect of any extraction application that recycles and/or recover solvents. At Koch Modular, we often supply extraction and distillation columns as a complete and integrated modular system for Solvent Recovery applications. Typical examples are illustrated on this page. From conceptualization through start-up, our professional and skilled engineers can provide sound guidance at every step of the liquid-liquid extraction process.
Advantages of Modular Construction for LLE
- Weather conditions do not affect work progress
- Single source responsibility
- Prevents plant site safety concerns as construction is done offsite
- Construction of modular system can proceed while permits are still pending
- Minimal plant site interruption
- Compressed schedule
- Lower initial lump sum bids and operational costs
LLE Development: Extraction Services From Bench Scale to Pilot Scale
Pilot tests are performed to certify the basis for most commercial plant designs. This is critical because liquid-liquid extraction separations typically face many unknown factors such as capacity data, entrainment tendency, interface behavior, emulsion formation, flood point, diffusion rates, and stage efficiency. In addition, small trace impurities can have a significant impact on the above-mentioned factors. For the most accurate results, customers should provide actual plant feed and solvent materials when conducting these tests.
Bench scale tests should be performed before pilot tests to generate liquid-liquid equilibrium data. In addition to acquiring equilibrium data, these tests also reveal information on entrainment and emulsions to help guide proper extractor selection.
Bench Scale and Pilot Scale Tests
- Selection of extraction technology for pilot test
- Settling times
- Mixing characteristics
- Equilibrium data
- Development of basis for performance guarantee for commercial scale system
- Optimization of liquid-liquid extraction separation
- Complete process demonstrations
- Useful data for scale-up projects (agitation speed, throughput, amd stage efficiency)
Koch Modular chooses the extraction technology based on our review of each application. Our team then runs pilot tests to demonstrate the process performance and provide data for scale-up. These pilot tests will be conducted in the same type of extraction column that is planned for the commercial scale. In some cases, more than one type of extraction technology will be tested to facilitate performance comparisons. See more details of Koch Modular’s Pilot Plant Capabilities.
Liquid-Liquid Extraction Column: Selection, Scale-up and Design
The extractor’s separation performance is typically measured during the pilot plant test. It may be measured over an array of effective heights, solvent-to-feed ratios, and flow rates. It is useful to note that the agitation speed varies if the selected extractor is agitated. The agitation is increased at each flow rate until a flood point is reached. The data from the Pilot Testing allows us to better determine the conditions that provide optimum volumetric efficiency.
The next step is scaling up to commercial size for installation at our customer’s plant. Scaleup procedures must determine how the power input varies with column size, how stage efficiency varies with diameter, and how diameter varies with throughput. In the final step, the extraction column will then be sized with the active zone height (along with the top and bottom settler zones) and any instrumentation that controls the column interface.
Koch Modular has a wide range of extractors to choose from, both static and agitated columns. Click on the column types below for more information on each.
Our team of experienced engineers is available to work together with you on your next liquid-liquid extraction application, from conceptualization through start-up.