Implementing a KARR® extraction column in the unit operations lab

The use of a continuous countercurrent Karr (R) extraction column for the senior unit operations lab at Villanova University is described. A number of issues were addressed in developing this experiment. These issues included the purpose of the experiment, the specific material system to use, i.e., the composition of the feed, extract and the solute, the volume of materials to process, safety concerns including toxicity and flammability of the materials, waste handling, the analytical technique needed to determine solute recovery, and identification of a design application related to the laboratory data. The experiment described here has been successfully used for three years without any significant problems. Student survey results and report grading rubrics indicate that the students understood important aspects of the fluid dynamics that govern mass transfer in a continuous extraction column and how to use lab data for a commercial design. Students also identified areas for potential improvement. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.