Performing Optimal Pilot Plant Tests for Design of Liquid-Liquid Extraction Columns

Due to the complexity of the processes taking place within an extraction process (e.g. droplet breakup/coalescing, mass transfer, and axial and radial mixing), and the fact that small amount of trace impurities can dramatically affect performance, it remains impossible today to size equipment with any reasonable degree of confidence and accuracy without pilot plant testing. For liquid-liquid extraction (LLE), a well designed and executed pilot plant test program is a powerful tool that can help process engineers optimize their designs and later help guide the plant personal towards successful start-up and operation. This paper will summarize the key elements to consider when evaluating a new extraction process and outline the thought process for setting up and performing a successful pilot test program for LLE. It will discuss the types of equipment used, parameters studied and the data collected to proceed with confidence to commercial scale-up. Actual examples of pilot plant tests will be presented wherein this method was used. These examples will show the equipment used, data generated and subsequent scale up to successfully plant LLE processes.