When it comes to Liquid-Liquid Extraction (LLE), much of the basic equilibrium data needed for design,that exists for, say, distillation design, just does not exist. When LLE is being considered we often measure liquid-liquid equilibrium data as a first step at our pilot plant.
When is LLE used?
• Separation is not feasible by distillation
• Breaking of azeotropes
• Energy requirements of distillation are prohibitive
• A complex distillation sequence is required
• The material is heat sensitive
• The solute material is non-volatile
The general rule: If a separation can be made economically by distillation, there is no reason to consider LLE. However, in situations where distillation is not feasible for reasons such as a complex process sequence, high investment or operating costs, heat sensitive materials, or low volatility, LLE is often the best technology to use and we head to our Houston-based pilot plant, often with clients alongside.
As Wendy Parker, Pilot Plant Director, said recently, “Clients will come to us with a problem first. Our skilled chemical engineers will work out how best to solve it, and then our pilot plant proves it.” Koch Modular provides a Process Performance Guarantee and will not build an extraction column without pilot plant testing the separation first.