Measuring Diesel Ash Emissions and Estimating Lube Oil Consumption Using a High Temperature Oxidation Method

Atomized fresh and used lube oil experiments showed that the HTOM reached stable particle size distributions and concentrations at temperatures above 700°C. The HTOM produced very similar number and volume weighted particle size distributions for both types of lube oils. The particle number size distribution was unimodal, with a geometric mean diameter of about 23 nm. The volume size distribution had a geometric volume mean diameter of about 65 nm.

Inductively coupled mass spectrometry (ICP-MS) was used to determine the ash content of different lube oils, revealing the differences in elemental compositions of ash for a fresh lube oil and an used lube oil; the most notable changes were a 166% increase in Mg and a 194% increase in Fe concentrations. The mass penetration fraction of lube oil using the HTOM was compared to the oil ash concentrations found from the ICP-MS analysis and the results are discussed.

The HTOM was also used to measure exhaust ash concentrations from a passenger car Diesel engine during steady-state and transient engine conditions. Using known oil ash compositions the HTOM was used to estimate engine oil consumption rates from exhaust ash measurements.