Development of a Process for the Production of Diesel Grade Engine Oil via Vacuum Distillation - Adsorption process

Abstract

This study presents the development of an integrated vacuum distillation-adsorption process for the efficient production of diesel-grade engine oil from waste lubricating oil. This process aims to recover valuable base oils while meeting the stringent quality specifications of modern diesel engines. Initial vacuum distillation, conducted at a vacuum pressure of -0.032 to -0.062MPa and a temperature range of 275-300°C, yielded a distillate fraction constituting approximately 75 wt% of the input waste oil. This fraction, characterized by a kinematic viscosity of 8.5 cSt at 100°C, subsequently underwent an adsorption step utilizing activated clay. Adsorption parameters, specifically a clay dosage of 3 wt% and a contact time of 60 min at 80°C, resulted in a significant reduction in total acid number (TAN) from 5.7 mg KOH/g to 5.0 mg KOH/g and an improvement in color from ASTM D1500 7.0 to 2.5. The final refined oil exhibited properties consistent with those of commercial diesel-grade engine oils, including a flash point of 154°C and a viscosity index of 11. This integrated approach demonstrates a promising and environmentally sound method for producing high-quality base oils, contributing to resource sustainability and the principles of a circular economy.