Unregulated Emissions from a Heavy-Duty Diesel Engine with Various Fuels and Emission Control Systems

Tang, Shida; Frank, Brian P.; Lanni, Thomas; Rideout, Greg; Meyer, Norman; Beregszaszy, Chris

doi:10.1021/es0622249

Cited by 53 publications

(29 citation statements)

References 25 publications

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“…The reductions in PAHs range from 80% to more than 99% relative to a 2000-technology engine. 19 All PAHs with more than four rings except fluoranthene and pyrene were below the detection limit. Table 8 reports a 92% reduction in nitroPAH compound emissions with the 2007-technology engines.…”

Section: Resultsmentioning

confidence: 94%

Regulated and Unregulated Emissions from Highway Heavy-Duty Diesel Engines Complying with U.S. Environmental Protection Agency 2007 Emissions Standards

Khalek

Bougher

Merritt

et al. 2011

Journal of the Air & Waste Management Association

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As part of the Advanced Collaborative Emissions Study (ACES), regulated and unregulated exhaust emissions from four different 2007 model year U.S. Environmental Protection Agency (EPA)-compliant heavy-duty highway diesel engines were measured on an engine dynamometer. The engines were equipped with exhaust high-efficiency catalyzed diesel particle filters (C-DPFs) that are actively regenerated or cleaned using the engine control module. Regulated emissions of carbon monoxide, nonmethane hydrocarbons, and particulate matter (PM) were on average 97, 89, and 86% lower than the 2007 EPA standard, respectively, and oxides of nitrogen (NO x ) were on average 9% lower. Unregulated exhaust emissions of nitrogen dioxide (NO 2 ) emissions were on average 1.3 and 2.8 times higher than the NO 2 emissions reported in previous work using 1998-and 2004-technology engines, respectively. However, compared with other work performed on 1994-to 2004-technology engines, average emission reductions in the range of 71-99% were observed for a very comprehensive list of unregulated engine exhaust pollutants and air toxic contaminants that included metals and other elements, elemental carbon (EC), inorganic ions, and gas-and particle-phase volatile and semi-volatile organic carbon (OC) compounds. The low PM mass emitted from the 2007 technology ACES engines was composed mainly of sulfate (53%) and OC (30%), with a small fraction of EC (13%) and metals and other elements (4%). The fraction of EC is expected to remain small, regardless of engine operation, because of the presence of the high-efficiency C-DPF in the exhaust. This is different from typical PM composition of pre-2007 engines with EC in the range of 10 -90%, depending on engine operation. Most of the particles emitted from the 2007 engines were mainly volatile nuclei mode in the sub-30-nm size range. An increase in volatile nanoparticles was observed during C-DPF active regeneration, during which the observed particle number was similar to that observed in emissions of pre-2007 engines. However, on average, when combining engine operation with and without active regeneration events, particle number emissions with the 2007 engines were 90% lower than the particle number emitted from a 2004-technology engine tested in an earlier program.

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Section: Resultsmentioning

confidence: 94%

Regulated and Unregulated Emissions from Highway Heavy-Duty Diesel Engines Complying with U.S. Environmental Protection Agency 2007 Emissions Standards

Khalek

Bougher

Merritt

et al. 2011

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

show abstract

“…17 Other studies have also reported similarly high EC and OC reductions across a range of engines, aftertreatment configurations, test cycles, and fuel sulfur content. 25,26,28,37,38 For example, Liu et al 28 observed >99% reductions for both EC and OC in their comprehensive study of emissions of more than 150 organic species from a 2007 engine representative of NTDE versus a 2004 non-retrofit engine (see Table 1 for engine specifications).…”

Section: Major Chemical Speciesmentioning

confidence: 99%

Particulate Matter in New Technology Diesel Exhaust (NTDE) is Quantitatively and Qualitatively Very Different from that Found in Traditional Diesel Exhaust (TDE)

Hesterberg

Long

Sax

et al. 2011

Journal of the Air & Waste Management Association

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Diesel exhaust (DE) characteristic of pre-1988 engines is classified as a "probable" human carcinogen (Group 2A) by the International Agency for Research on Cancer (IARC), and the U.S. Environmental Protection Agency has classified DE as "likely to be carcinogenic to humans." These classifications were based on the large body of health effect studies conducted on DE over the past 30 or so years. However, increasingly stringent U.S. emissions standards for particulate matter (PM) and nitrogen oxides (NO x ) in diesel exhaust have helped stimulate major technological advances in diesel engine technology and diesel fuel/lubricant composition, resulting in the emergence of what has been termed New Technology Diesel Exhaust, or NTDE. NTDE is defined as DE from post-2006 and older retrofit diesel engines that incorporate a variety of technological advancements, including electronic controls, ultra-low-sulfur diesel fuel, oxidation catalysts, and wall-flow diesel particulate filters (DPFs). As discussed in a prior review (T. W. Environ. Sci. Technol. 2008, 42, 6437-6445), numerous emissions characterization studies have demonstrated marked differences in regulated and unregulated emissions between NTDE and "traditional diesel exhaust" (TDE) from pre-1988 diesel engines. Now there exist even more data demonstrating significant chemical and physical distinctions between the diesel exhaust particulate (DEP) in NTDE versus DEP from pre-2007 diesel technology, and its greater resemblance to particulate emissions from compressed natural gas (CNG) or gasoline engines. Furthermore, preliminary toxicological data suggest that the changes to the physical and chemical composition of NTDE lead to differences in biological responses between NTDE versus TDE exposure. Ongoing studies are expected to address some of the remaining data gaps in the understanding of possible NTDE health effects, but there is now sufficient evidence to conclude that health effects studies of pre-2007 DE likely have little relevance in assessing the potential health risks of NTDE exposures. INTRODUCTIONDiesel-engine exhaust (DE) exposures and health effects have been studied extensively for decades. DE is a source of particulate matter (PM), nitrogen oxides (NO x ), carbon monoxide (CO), and a number of air toxics (e.g., aldehydes,

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“…Tang et al reported that for all of the fuels studied the TC mass emissions were reduced by the DOC and the EC/OC ratio was increased due to more reduction of OC than EC emissions [18]. In this study, the variation of the OC/EC ratio after the DOC was not consistent and depended on operating conditions.…”

Section: Pm Sampling and Composition Analysismentioning

confidence: 54%

Effects of a diesel oxidation catalyst on gaseous pollutants and fine particles from an engine operating on diesel and biodiesel

Shi

Song

et al. 2011

Front. Environ. Sci. Eng.

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The effects of a diesel oxidation catalytic (DOC) converter on diesel engine emissions were investigated on a diesel bench at various loads for two steady-state speeds using diesel fuel and B20. The DOC was very effective in hydrocarbon (HC) and CO oxidation. Approximately 90%-95% reduction in CO and 36%-70% reduction in HC were realized using the DOC. Special attention was focused on the effects of the DOC on elemental carbon (EC) and organic carbon (OC) fractions in fine particles (PM 2.5 ) emitted from the diesel engine. The carbonaceous compositions of PM 2.5 were analyzed by the method of thermal/optical reflectance (TOR). The results showed that total carbon (TC), OC and EC emissions for PM 2.5 from diesel fuel were generally reduced by the DOC. For diesel fuel, TC emissions decreased 22%-32% after the DOC depending on operating modes. The decrease in TC was attributed to 35%-97% decrease in OC and 3%-65% decrease in EC emissions. At low load, a significant increase in the OC/EC ratio of PM 2.5 was observed after the DOC. The effect of the DOC on the carbonaceous compositions in PM 2.5 from B20 showed different trends compared to diesel fuel. At low load, a slight increase in EC emissions and a significant decrease in OC/EC ratio of PM 2.5 after DOC were observed for B20.

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Unregulated Emissions from a Heavy-Duty Diesel Engine with Various Fuels and Emission Control Systems

Cited by 53 publications

References 25 publications

Regulated and Unregulated Emissions from Highway Heavy-Duty Diesel Engines Complying with U.S. Environmental Protection Agency 2007 Emissions Standards

Regulated and Unregulated Emissions from Highway Heavy-Duty Diesel Engines Complying with U.S. Environmental Protection Agency 2007 Emissions Standards

Particulate Matter in New Technology Diesel Exhaust (NTDE) is Quantitatively and Qualitatively Very Different from that Found in Traditional Diesel Exhaust (TDE)

Effects of a diesel oxidation catalyst on gaseous pollutants and fine particles from an engine operating on diesel and biodiesel

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