Liquid-Liquid extraction is a method of purifying a substance. This is achieved by dissolving the crude material in a solvent- in which other parts of the feed material are soluble. This method worked remarkably well in a project spearheaded by Koch Modular, in which the goal was to purify motor oil through the liquid-liquid extraction process.

In order to remove the impurities from recycled motor oil, a continuous countercurrent extraction process was required. We followed this with a vacuum distillation to recover the extraction solvent.

Pilot Testing of oil purification through liquid-liquid extraction began at the Koch Modular Process Systems pilot plan in Houston, Texas. A SCHEIBEL® extractor was selected for this application.