No increase in ultra-fine particles from biodiesel

The study measured exhaust gas for a heavy-duty engine using four different fuels: biodiesel (B100); fossil diesel fuel; Shell V-Power diesel fuel; and a blend of Aral Ultimate diesel fuel with 5% biodiesel. The aim was to examine the apparent increase in ultra-fine particles that is observed when biodiesel is used instead of fossil diesel fuel.

Diminished
Results showed that, except for NOx, biodiesel actually emitted less ultra-fine particles. If an oxidation catalytic converter (DOC) was used, then the oxidizable components of the exhaust could also be diminished. Further analysis of the exhaust gas showed that the ultra-fine particles that were emitted consisted mainly of unburned fuel and not of potentially harmful soot.

The authors of the report say that the results conclusively show that biodiesel does not lead to an increased emission of harmful ultra-fine particles.

Federal Agricultural Research Center
The study, Measurement of ultra-fine particles in the exhaust gas of diesel engines fuelled with biodiesel, was carried out at the Institute for Technology and Biosystems Engineering of the Federal Agricultural Research Center (FAL) in Braunschweig, in cooperation with the Steinbeis Transfer Center for Biofuels and Environmental Analysis, Coburg.

The project was funded by the Fachagentur Nachwachsende Rohstoffe (FNR – Agency of Renewable Resources), the Union zur Förderung von Oel- und Proteinpflanzen (UFOP – Union for the Promotion of Oil and Protein Plants) and the Verband der Deutschen Biokraftstoffindustrie (VDB – Association of the German Biofuels Industry).