Emissions of PAHs, Nitro-PAHs and Quinones (Oxy-PAHs) Associated to PM_1.0 and PM_2.5 Emitted by a Diesel Engine Fueled with Diesel-Biodiesel-Ethanol Blends

Abstract

Emissions of PAH, nitro-PAHs, and oxy-PAHs from a diesel engine fueled with diesel-biodiesel-ethanol blends need to be controlled and reduced, as they are unregulated emissions harmful to the environment and human health. The objective of this work was to investigate the effect of ethanol concentration on diesel engine emissions when fueled with diesel–biodiesel–ethanol blends. Ethanol was added with biodiesel–diesel blends. Diesel B7 and two ternary blends, B7E3 and B7E10, with 3% and 10% ethanol, were tested and studied in a diesel engine to determine engine performance characteristics and particulate matter emissions and to quantify polycyclic aromatic compounds (PACs) associated with PM1.0 and PM2.5. Under the same engine conditions, 18 PAHs, 27 nitro-PAHs, and 6 quinones (oxy-PAHs) were determined by GC–MS in real samples obtained from the engine. The mean concentrations of PACs found in the B7, B7E3, and B7E10 blends for PM1.0 ranged from 0.1 µg m−3 (coronene) to 118.1 µg m−3 (2-nitrofluorene). The concentrations for PM2.5 ranged from 0.1 µg m−3 (acenaphthylene) to 99.7 µg m−3 (2-nitrofluorene). Potent mutagens benzanthrone (BA) and 3-nitrobenzanthrone (3-NBA) were found at concentrations ranging from 0.10 µg m−3 to 1.9 µg m−3 and 0.3 µg m−3 to 1.6 µg m−3, respectively. Low molecular weight (LMW) PAHs were mainly PACs bounded to the PM1.0 and PM2.5 particles emitted by B7E10. Flow properties were improved by adding 3% and 10% ethanol to biodiesel. B7E3 and B7E10 blends presented low fuel consumption and a reduction in the emission factor (EF) by the engine. B7E10 blending showed a smaller total concentration of ∑PAH (26.8 µg m−3), ∑nitro-PAH (85.4 µg m−3), and ∑oxy-PAH (6.0 µg m−3) associated with PM2.5 particles compared PM1.0.

Keywords

• fuel blends
• fine particles
• PAHs
• nitro-PAHs
• oxy-PAHs