The Liquid-Liquid Extraction Process:
Development From Bench Scale to Pilot Scale
Most projects involve a pilot test to provide the basis for commercial plant design. Unlike distillation, which can often be designed by simulations alone, liquid-liquid extraction usually has many unknown factors such as stage efficiency, rates of diffusion, flood point, emulsion formation, interface behavior, entrainment tendency and capacity data. Small trace impurities can have a significant impact on all of the above. For this reason, it is preferred to use only actual plant feed and solvent materials are best used for these tests.
Before pilot testing begins bench scale tests are performed to generate the liquid-liquid equilibrium data. Besides supplying the equilibrium data, these tests can reveal information on emulsions or entrainment that help guide extractor selection.
Information From Liquid-Liquid Extraction
Bench Scale Tests Provide
- Equilibrium data
- Mixing characteristics
- Settling times
- Extractor type selection for pilot test
Pilot Scale Tests Provide
- Data for scale-up > stage efficiency, throughput, agitation speed
- Demonstration of the entire process
- Process optimization
- Basis for performance guarantee
We select the appropriate extractor based on our review of each application. Pilot tests are then run to demonstrate the process performance as well as provide data for scale-up. These pilot tests are performed in the same type of extractor planned for the commercial scale. In some cases, more than one type of extractor will be tested to compare performance.
See more details of Koch Modular’s Pilot Plant Capabilities.