AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Characterizing the Gaseous Toxic Pollutants, Ultrafine Particle Emissions, Size Distributions, Electrophilic, and Redox Properties of Biodiesel Exhaust from Heavy-Duty Vehicles with and without Aftertreatment Controls
NICHOLAS GYSEL, Thomas D. Durbin, Debra A. Schmitz, Arthur K. Cho, Georgios Karavalakis, University of California Riverside
Abstract Number: 451 Working Group: Combustion
Abstract Fuels derived from biological sources, such as fatty acid methyl esters (FAMEs), have received and continue to receive increasing attention. For this study, we examined the emissions impacts of high biodiesel blends of different origin on the exhaust emissions from two heavy-duty trucks equipped with different aftertreatment configurations. Experiments were conducted on a 2012 Cummins ISX15 engine fitted a diesel particle filter (DPF) and selective catalytic reduction (SCR) control devices and on a 2004 Cummins ISX450 engine without an aftertreatment control device. Each truck was tested on four different fuels including a CARB diesel and three biodiesel blends at 50 percent proportion with the CARB diesel. The biodiesel used were a soy-based biodiesel, an animal fat biodiesel, and a biodiesel obtained from waste cooking oils.
For this study, gaseous toxics were analyzed for aldehydes and ketones and for light aromatic hydrocarbons. Chemical analysis for carbonyl compounds and VOCs was performed using a HPLC and a GC-MC, respectively. Emphasis was placed on the measurement of real-time particle size distributions using an engine exhaust particle sizer (EEPS) spectrometer and on the determination of particle number emissions using a condensation particle counter (CPC). Particulate matter 2.5 micro-meter samples and semi-volatile compounds were collected in Teflon filters and XAD-4 resin, respectively, and subsequently analyzed for redox activity by DTT assay and electrophilic properties by GAPDH assay. Preliminary results showed that biodiesel blends resulted in pronounced reductions in particle number emissions for the newer vehicle, while particle number emissions trended higher with biodiesel for the older technology vehicle. For all fuels and both vehicles, particles showed a consistent nucleation mode. Additionally, the use of biodiesel led to reduced DTT activity compared to diesel fuel. This suggests that addition of biodiesel to diesel may result in less toxic emissions and thus reduce adverse health effects and improve urban air quality.