Waste Lubricant Oil Regeneration by Solvent Extraction with Membrane Separation

Abstract

Japan generates about 1 million kL of used lubricant oil annually, only 2 % of which is recycled as regenerated oil. The method presented in this report using solvent extraction with membrane separation produces few residual products : only impurities remaining in a membrane rubber bag. For this study, a continuous regeneration system was set up and operated with two waste lubricant oil samples. The oil recovery rate was estimated over time. Oil quality was tested before and after regeneration processing. Sulfur contents, carbon residue, viscosity at 40 °C, carbon number distribution, and water content were analyzed to assess the oil quality. Continuous regeneration up to 15 h was achieved. The regenerated base oil quality was confirmed, showing no degradation during 15 h extraction.