Effects of fuels, engine load and exhaust after-treatment on diesel engine SVOC emissions and development of SVOC profiles for receptor modeling

Abstract

Diesel exhaust emissions contain numerous semivolatile organic compounds (SVOCs) for which emission information is limited, especially for idling conditions, new fuels and the new after-treatment systems. This study investigates exhaust emissions of particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and sterane and hopane petroleum biomarkers from a heavy-duty (6.4 L) diesel engine at various loads (idle, 600 and 900 kPa BMEP), with three types of fuel (ultra-low sulfur diesel or ULSD, Swedish low aromatic diesel, and neat soybean biodiesel), and with and without a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF). Swedish diesel and biodiesel reduced emissions of PM2.5, Σ15PAHs, Σ11NPAHs, Σ5Hopanes and Σ6Steranes, and biodiesel resulted in the larger reductions. However, idling emissions increased for benzo[k]fluoranthene (Swedish diesel), 5-nitroacenaphthene (biodiesel) and PM2.5 (biodiesel), a significant result given the attention to exposures from idling vehicles and the toxicity of high-molecular-weight PAHs and NPAHs. The DOC + DPF combination reduced PM2.5 and SVOC emissions during DPF loading (>99% reduction) and DPF regeneration (83–99%). The toxicity of diesel exhaust, in terms of the estimated carcinogenic risk, was greatly reduced using Swedish diesel, biodiesel fuels and the DOC + DPF. PAH profiles showed high abundances of three and four ring compounds as well as naphthalene; NPAH profiles were dominated by nitro-naphthalenes, 1-nitropyrene and 9-nitroanthracene. Both the emission rate and the composition of diesel exhaust depended strongly on fuel type, engine load and after-treatment system. The emissions data and chemical profiles presented are relevant to the development of emission inventories and exposure and risk assessments.

Characterization of Gas and Particulate Phase Organic Emissions (C9–C37) from a Diesel Engine and the Effect of Abatement Devices

“…A limited number of studies have therefore investigated S/IVOC emissions under steady-state engine conditions (constant engine torque, speed, etc.) with and without emission control technologies 15,16,17 .…”

New Leakage Current Particulate Matter Sensor for On-Board Diagnostics

“…But the high PM emission of diesel engine will have great influence on human health and environment [1,2]. Diesel particulate filters (DPF) have been widely used in diesel vehicles to remove PM from exhaust gas and help meet stringent legislation [3][4][5]. On-board diagnostics (OBD) require monitoring of the DPF system for malfunction that may cause PM emission to exceed the regulated levels.…”

Airborne Dioxins, Furans, and Polycyclic Aromatic Hydrocarbons Exposure to Military Personnel in Iraq

“…Diesel vehicles are known to be sources of airborne PAHs. 41,42,43,44,45 In addition to the ground vehicles, there were aircraft (fixed wing and helicopters) that are sources of PAH emissions. 46,47 Diesel generators were used at multiple sites across JBB to provide electricity.…”

“…In particular, PCDDs+Fs and PAHs profiles were derived from: simulated deployed US military waste emissions; 39 legacy (1985 6.2L and 1993 10L) heavy-duty diesel engines at transient on-road settings; 43 common in-use heavy-duty diesel engines (1998 11L) without after-treatment devices at cruise, urban, and idling speeds; 44 modern diesel engines (2008 6.7L and 2008 6.4L) with and without exhaust gas after-treatment at average conditions; 42,45 various aircraft turbofan engines. 47,57 …”