We systematically examined the effects of blending ultralow sulfur diesel (ULSD) with five different oxygenates at 2% and 4% oxygen levels on the carbonaceous composition of both total diesel particulate matter (DPM) and size-segregated DPM, respectively.

The study demonstrates that despite all diesel-oxygenate blends are effective in promoting soot (or elemental carbon, EC) oxidation in all size ranges and in reducing the total engine-out DPM mass concentrations, but lead to a significant increase in organic carbon (OC) and water-soluble organic carbon (WSOC) fractions. Smaller particles had higher fractions of OC, particle-bound PAHs and n-alkanes, which varied with the type and content of oxygenates used.