Evaluation of physico-chemical properties of re-refined lubricating oils obtained from fabricated packed bed reactor

Abstract

This study aimed at fabricating a packed bed reactor (PBR) and evaluating its performance on improving physico-chemical properties of used lubricating oils. The sorbent used was a composite of bentonite, limestone, diatomite, quartz, and wood charcoal in the same ratio by mass. Samples of used lubricating oils from two brands (Mobil Super SAE 20W-50 and Total Quartz 5000 SAE 20W-50) were run through the fabricated PBR. The mean values of the analyzed physico-chemical parameters (kinematic viscosity, viscosity index, flash point, pour point, acid number, base number, iodine value, ash content, density, and refractive index) of the exuded (treated) oils were compared with those of used and virgin oils of the same brand. Apart from the iodine value, the mean values obtained for the treated oil samples are close to those of virgin oil samples. The t-test results indicated that most of the parameters showed significant difference between their mean values in the used oils indicating distinct properties and hence, good treatment effects, while a good number showed no significant difference between their mean values in the treated Mobil and treated Total oils, indicating similar properties and that the treatment had similar effects on the two brands of oils. Also, various results of cross plots had R2 values greater than 0.96, indicating high linear relationships of the impact of the treatment on the various oil samples. The overall results established the high effectiveness of the fabricated PBR for the treatment of used lubricating oils.