PHYSICAL AND CHEMICAL PROPERTIES OF DIESEL ENGINE EXHAUST AND LUBRICATING OIL PARTICULATES

Abstract

Abstract: To systematically investigate the differences in physical and chemical properties between diesel engine exhaust particulates (DS) and in-use lubricating oil particulates (LS), the exhaust particulates from a China VI diesel engine and the in-use lubricating oil particulates from the same engine were collected. The differences in physical and chemical properties between the two types of particulates were examined using high-resolution transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analyzer, and the reasons for the differences in particulate properties were discussed.The results show that both types of particulates exhibit a typical "core-shell" structure. The average particle sizes of DS and LS particulates are 58.2 nm and 52.6 nm, respectively. Both types of particulates are mainly composed of C and H. Functional elements of lubricating oil such as Ca, S, P, and Zn are found in LS particulates, and Ca mainly exists in the forms of CaSO₄ and CaO. Compared with DS, LS had the following characteristics: slightly higher graphitization degree and slightly thinner graphite shell; slightly higher fractal dimension and greater particle structure compactness; slightly higher oxidation activity, making it more prone to oxidation reactions.

Key words: particulates, diesel engine, lubricanting oil, nanoscale microstructure, oxidation characteristics

References

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