Composition-Explicit Distillation Curves of Waste Lubricant Oils and Resourced Crude Oil: A Diagnostic for Re-Refining and Evaluation

Abstract

Problem statement: We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. The modifications include a composition-explicit data channel for each distillate fraction and temperature measurements that are true thermodynamic state points that can be modeled with an equation of state. The composition-explicit information is achieved with a sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the method (called the advanced distillation curve technique) to a variety of fluids, including simple n-alkanes, rocket propellants, gasoline, jet fuels, diesel and biodiesel fuels and crude oils (both petroleum-and bio-derived crude oils). Approach: In this study, we present the application of the method to new, recycled and resourced heavy oils. The ultimate purpose of this work is waste reduction and energy utilization, by placing the reprocessing steps on a more fundamental footing. First, we present measurements on four unused automotive crankcase oils and then four samples of used oils: automotive oil, cutting oil, transformer oil and a commingled lubricant waste stream. Using the advanced distillation curve metrology, we can distinguish between the different weights (viscosity ranges) of crankcase oils and compare them to the sample of used crankcase oil. The distillation curves also provide valuable information regarding the presence or absence of low-boiling contaminants in the recycled automotive oil, such as water and gasoline. Results: Additionally, we demonstrate the evaluation of all four used lubricant oils. Then, we apply the advanced distillation curve method to a sample of crude oil prepared using a plastic waste stream from an automotive plant. Conclusion: Overall, we conclude that the composition-explicit advanced distillation curve metrology is important for understanding the boiling behavior of the various oils streams and is a valuable diagnostic for future re-refining of the used lubricant oils. This information will be essential in the development of models for the thermophysical properties of such fluids.