title: Physicochemical characterization of particulate emissions from a compression ignition engine: the influence of biodiesel feedstock.
abstract: This study undertook a physicochemical characterization of particle emissions from a single compression ignition engine operated at one test mode with 3 biodiesel fuels made from 3 different feedstocks (i.e., soy, tallow, and canola) at 4 different blend percentages (20%, 40%, 60%, and 80%) to gain insights into their particle-related health effects. Particle physical properties were inferred by measuring particle number size distributions both with and without heating within a thermodenuder (TD) and also by measuring particulate matter (PM) emission factors with an aerodynamic diameter less than 10 μm (PM(10)). The chemical properties of particulates were investigated by measuring particle and vapor phase Polycyclic Aromatic Hydrocarbons (PAHs) and also Reactive Oxygen Species (ROS) concentrations. The particle number size distributions showed strong dependency on feedstock and blend percentage with some fuel types showing increased particle number emissions, while others showed particle number reductions. In addition, the median particle diameter decreased as the blend percentage was increased. Particle and vapor phase PAHs were generally reduced with biodiesel, with the results being relatively independent of the blend percentage. The ROS concentrations increased monotonically with biodiesel blend percentage but did not exhibit strong feedstock variability. Furthermore, the ROS concentrations correlated quite well with the organic volume percentage of particles - a quantity which increased with increasing blend percentage. At higher blend percentages, the particle surface area was significantly reduced, but the particles were internally mixed with a greater organic volume percentage (containing ROS) which has implications for using surface area as a regulatory metric for diesel particulate matter (DPM) emissions.
authors: ILAQH, Institute of Health and Biomedical Innovation, Queensland University of Technology, 2 George Street, Brisbane QLD 4001, Australia.
authors: N C
authors: NC
authors: Surawski
authors: B
authors: B
authors: Miljevic
authors: G A
authors: GA
authors: Ayoko
authors: S
authors: S
authors: Elbagir
authors: S
authors: S
authors: Stevanovic
authors: K E
authors: KE
authors: Fairfull-Smith
authors: S E
authors: SE
authors: Bottle
authors: Z D
authors: ZD
authors: Ristovski
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000737:chemistry*; D056804:Biofuels / Q000032:analysis*; D003246:Conservation of Energy Resources; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D017382:Reactive Oxygen Species / Q000032:analysis; D018570:Risk Assessment; D001335:Vehicle Emissions
chemical_list: D000393:Air Pollutants; D056804:Biofuels; D052638:Particulate Matter; D011084:Polycyclic Aromatic Hydrocarbons; D017382:Reactive Oxygen Species; D001335:Vehicle Emissions