AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Biodiesel Effects on Black Carbon Emissions from a Diesel Engine
YUAN CHENG, Shao-Meng Li, John Liggio, Katherine Hayden, Tak Chan, Marie-Josee Poitras, Environment Canada
Abstract Number: 67 Working Group: Source Apportionment
Abstract More than 50 countries have set goals to replace a substantial fraction of transport fuel with biofuels (mainly biodiesel and bioethanol). Therefore, the impacts of biofuel on emissions from the transportation sector require careful evaluation. This is particularly true for black carbon (BC) emissions from diesel engines due to the strong radiative forcing on global and regional climate associated with BC. An experimental system capable of achieving dilution ratios representative of ambient conditions was used to measure the emission factors of particulate matter components, where BC was measured by a single particle soot photometer. Using this system, we investigated the effect of biodiesels on BC emissions from a light-duty diesel engine. Three biodiesels, based on soybean, tallow/waste fry oil, and canola oil, were investigated under three driving modes representing aggressive, highway and city average driving behaviors. Apart from the use of baseline ultra low sulphur diesel (ULSD), four blend levels (B5, B20, B50 and B100) were used in the biodiesel tests. In general, decreases in the BC emission factor were observed with increasing biodiesel content in the blends. Moreover, large reductions in BC emissions were found with the low blending level of B05; increasing the blending level higher brings incremental reductions in BC emissions but not proportional to the blending level. For example, a 70% BC emission reduction was achieved with the B5 soybean biodiesel blend versus a 90% reduction seen with the B100 soybean biodiesel at the highway mode. Higher load engine operation conditions lead to larger BC emission reductions; for example, a 60% emission reduction with B20 canola oil was observed at the city average driving mode, versus an 85% reduction achieved at the aggressive driving mode. These results are important for modeling and regulating the impacts of vehicle emissions into the future.