Pilot Plant Testing for Liquid-Liquid Extraction and Distillation

Accurate design for liquid-liquid extraction (LLE) columns and distillation columns often requires pilot plant testing in order to ensure accurate sizing for production columns. Simulations are useful to determine many of the process conditions required for a given separation, but often times these are not sufficient to determine the efficiency and capacity of the column. In many instances, pilot plant testing is required to accurately determine HETP (which sets the column height) and optimal capacity (which sets the column diameter). When testing in a pilot plant, it is imperative to use the minimum size column that is possible, in order to minimize the amount of feed and time required for a test program. This presentation will show the minimum size columns that can be used to effectively generate scale-up data, and will utilize an actual example for both LLE and distillation. LLE testing can be accomplished in a 1” or 3” dimeter column, depending on the column type used. Distillation is performed in 3” – 6” diameter columns with either structured packing or sieve trays. With good experience and an effective test method, the required data can be collected within one calendar week.