Exhaust particle properties from a light duty diesel engine using different ash content lubricating oil

Abstract

Three kinds of lubricating oil with different ash contents were used in a light-duty diesel engine to investigate exhaust particle properties. This study applied transmission electron microscopy (TEM) equipped with energy dispersal x-ray spectroscopy (EDX). Results show that with increasing ash content in the lubricating oil, the macroscopical structure of diesel particles transforms from chain-like to a more complex and disordered agglomerated structure. The outer ordered carbon layers of the core–shell structure become thinner. The thickness of the amorphous materials attached onto the outer carbon layer increases. The mean diameter of the primary particles first increases and then decreases. The content of C element in particles decreases with increasing ash content in lubricating oil, while the content of the O element increases, as does the content of trace elements in diesel exhaust particles.