oil aging

The paper deals with the results of the study on the purification process of used mineral and semi-synthetic motor oils in the presence of crystalline urea. The effect of the process main factors (the amount of the main reagent, time, and temperature) on the performance indicators of purified motor oils was studied. Used mineral and semi-synthetic motor oils for gasoline and diesel engines were purified under the established optimal conditions.

The changes in operational and physico-chemical properties of original and used semi-synthetic motor oil Castrol 10W-40 before and after its use in a diesel engine have been investigated. Derivatographic studies were carried out to examine a thermal stability; IR spectroscopy was used to confirm the presence of oil aging products. The composition of the inorganic part of the studied semi-synthetic oils was established by X-ray fluorescence analysis.