Impact of FAME Content on the Regeneration Frequency of Diesel Particulate Filters (DPFs)

Report no. 14/16: Modern diesel passenger cars utilize Diesel Particulate Filters (DPFs) to reduce particulate matter exhaust emissions. In addition oxygenated fuels and fuel blending components such as Fatty Acid Methyl Esters (FAMEs) are known to reduce PM formation in the combustion chamber and reduce the amount of soot that must be filtered from the engine exhaust by the DPF. This effect is also expected to lengthen the time between DPF regenerations and reduce the fuel consumption penalty that is associated with DPF loading and regeneration.

This study investigated the effect of FAME content, up to 50% v/v (B50), in diesel fuel on the DPF regeneration frequency by repeatedly running a Euro 5 multi-cylinder bench engine over the European regulatory cycle (NEDC) until a specified soot loading limit had been reached. The results verified the expected reduction of engine-out particulate mass (PM) emissions with increasing FAME content and the reduction
in fuel economy penalty associated with reducing the frequency of DPF regenerations. Fuel dilution measurements on lubricant samples taken from the engine sump showed that the FAME content in the engine lubricant increased with higher FAME contents in the fuel blends.