The application of biodiesel fuel (BDF) to diesel engines is very effective at reducing CO2 emissions, because biodiesel is considered to be carbon neutral in principle. Gas-to-liquid (GTL) fuel, a synthetic fuel, is expected to reduce emissions from diesel engines. This study focused on the effects of driving conditions and fatty acid methyl ester (FAME) and GTL blended fuel on emissions from diesel engines/vehicles meeting Japan's new short-term regulations, or '03 regulations. FAME including rape methyl ester (RME), palm oil methyl ester (PME) and soybean methyl ester (SME) were studied.
Major technologies for emissions reduction may include common-rail high-pressure fuel injection system, cooled exhaust gas recirculation (EGR) system, diesel oxidation catalyst (DOC) and diesel particulate filter (DPF). Various driving cycles with a wide range of average vehicle speeds and accelerations were selected, including US Highway cycle, Japanese JC08 and JE05 mode driving cycles, and Tokyo Metropolitan Government driving cycles #2 (TMG-2) and #5 (TMG-5).
GTL and FAME-blended fuels were used as test fuels, the blending rate was varied from 0 to 100%. PM emissions including soluble organic fraction (SOF) and soot, NOx, THC, CO and aldehyde compounds were examined. The emissions reduction effect of DOC and DPF was also investigated.