Unregulated Exhaust Emissions from Alternate Diesel Combustion Modes

Merritt, Patrick M.; Huang, Yuhao; Khair, Magdi; Pan, Joseph

doi:10.4271/2006-01-3307

Cited by 18 publications

(6 citation statements)

References 3 publications

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“…Other contributing species include low-volatility components like methyl ester in biodiesel and polycyclic aromatic hydrocarbons (PAHs) present in diesel fuel and from combustion. The study by Merritt et al (2006) on unregulated emissions from CDC and LTC showed orders of magnitude increases of particle forming PAH compounds for LTC modes in comparison to CDC modes. Other studies suggest that species beyond PAH and unburned fuel contribute to LTC particles.…”

Section: Introductionmentioning

confidence: 97%

“…Prikhodko et al (2010) showed an order of magnitude increase in HC for low load RCCI compared to equivalent speed and load CDC. These emissions contain a range of organic compounds with molecular weight ranging from methane to unburned fuel molecules and heavy polycyclic aromatic (PAH) compounds (Merritt et al 2006). In-cylinder formation mechanisms and speciation of HCs from LTC have been studied (Knafl et al 2006;Colban et al 2007;Han et al 2008).…”

Section: Introductionmentioning

confidence: 99%

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Volatility characterization of nanoparticles from single and dual-fuel low temperature combustion in compression ignition engines

Lucachick

Curran

Storey

et al. 2016

Aerosol Science and Technology

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This work explores the volatility of particles produced from two diesel low temperature combustion (LTC) modes proposed for high-efficiency compression ignition engines. It also explores mechanisms of particulate formation and growth upon dilution in the near-tailpipe environment. The number distribution of exhaust particles from low-and mid-load dual-fuel reactivity controlled compression ignition (RCCI) and single-fuel premixed charge compression ignition (PPCI) modes were experimentally studied over a gradient of dilution temperature. Particle volatility of select particle diameters was investigated using volatility tandem differential mobility analysis (V-TDMA). Evaporation rates for exhaust particles were compared with V-TDMA results for candidate pure nalkanes to identify species with similar volatility characteristics. The results show that LTC particles are mostly comprised of material with volatility similar to engine oil alkanes. V-TDMA results were used as inputs to an aerosol condensation and evaporation model to support the finding that smaller particles in the distribution are comprised of lower volatility material than large particles under primary dilution conditions. Although our results show that saturation levels are high enough to drive condensation of alkanes onto existing particles under the dilution conditions investigated, they are not high enough to allow homogeneous nucleation of these same compounds in the primary exhaust plume. Therefore, we conclude that observed particles from LTC operation must grow from low concentrations of highly nonvolatile compounds present in the exhaust. EDITOR Matti Maricq

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Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Volatility characterization of nanoparticles from single and dual-fuel low temperature combustion in compression ignition engines

Lucachick

Curran

Storey

et al. 2016

Aerosol Science and Technology

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“…The volatile organic compounds (VOC) from diesel engines, including aldehydes, which cause the sickhouse syndrome, and benzene, which is a carcinogen, are of concern and remain as unregulated harmful substances [1][2][3][4][5][6][7][8]. Twelve substances from diesel engines, including formaldehyde, have been listed as unregulated harmful substances in Japan.…”

Section: Introductionmentioning

confidence: 99%

“…As it is considered that the concentrations of these volatile organic substances often have positive correlations to total hydrocarbon (THC) concentrations, the characteristics of unregulated harmful exhaust-gas emissions have to be grasped under high THC emission, including conditions of low coolant temperature [4]. While lowtemperature diesel combustion (LTC) and premixed charge compression ignition combustion (PCCI) can simultaneously realize ultra-low NO x and low particulate emissions [6][7][8][9][10][11][12][13][14][15][16][17][18][19], high levels of VOC and polycyclic aromatic hydrocarbons (PAH) as well as unburned hydrocarbon and CO emissions are observed with these new combustion regimes [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Volatile Organic Compounds in Exhaust Gas from Diesel Engines under Various Operating Conditions

Ogawa

2011

International Journal of Engine Research

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The volatile organic compounds (VOC) from diesel engines, including formaldehyde and benzene, are of concern and remain as unregulated harmful substances. These substances are positively correlated with total hydrocarbon (THC) emissions, but the VOC and aldehyde compounds at light load or idling conditions are more significant than THC. When coolant temperatures are low at light loads, there are notable increases in formaldehyde and acetaldehyde, and with lower coolant temperatures the increase in aldehydes is more significant than the increase in THC. With ultra-high exhaust-gas recirculation (EGR) suppressing in-cylinder soot and NO x formation, VOC increase drastically with intake oxygen content below 14 per cent. These trends correlate well with the drastic increase in THC emissions. Oxidation catalysts are effective for reducing some VOC emissions, including aldehydes and some unsaturated hydrocarbons. However, aromatics and methane generated from ultra-high EGR, low-temperature smokeless combustion, are hardly reduced with the catalysts, particularly under overall rich conditions.

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“…Various researchers have demonstrated the possibility of greatly decreasing HC and CO emissions, while maintaining very low NO x and PM mass emissions, through increased intake pressure to enhance the in-cylinder fuel-air mixing and combustion. [18,19,[35][36][37][38][39][40][41][42] Two understandings of HC emissions from premixed combustion have been proposed. [19] The first possible source of HC emissions is from under-mixed regions which don't allow sufficient mixing with the available oxygen for the fuel to fully combust.…”

Section: Introductionmentioning

confidence: 99%

Effects of intake pressure on particle size and number emissions from premixed diesel low-temperature combustion

Desantes

Benajes

García-Oliver

et al. 2013

International Journal of Engine Research

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SAGE Publications (UK and US)Desantes Fernández, JM.; Benajes Calvo, JV.; García Oliver, JM.; Kolodziej, CP. (2014). Effects of intake pressure on particle size and number emissions from premixed diesel lowtemperature combustion. ABSTRACTIn this study, ten premixed Diesel Low Temperature Combustion engine operating conditions were chosen based on engine intake pressure (1.2 -1.6 bar), intake oxygen concentration (10%, 11%, and 12%), and injection timing (-24°aTDC in all cases). At each intake oxygen concentration, the effect of intake pressure on combustion parameters and emissions measurements (carbon monoxide, hydrocarbons, nitrogen oxides, particulate matter mass concentration, and particle size distributions) was analyzed. Although increased intake pressure resulted in higher in-cylinder charge air density which improved fuel-air premixing and late-cycle oxidation quality, higher intake pressure also advanced the start of combustion (SOC) and thereby decreased the time available for fuel and air premixing. But even with the decrease in premixing time available before SOC, increased intake pressure caused significant decreases in carbon monoxide, hydrocarbon, particulate matter (PM) mass, and particle number emissions. Particle size distribution measurements allowed greater understanding of how higher intake pressure decreased the PM mass concentrations with respect to particle size. To further investigate the experimental results, a 0D engine heat release code was used to analyze combustion temperatures and a 1D free spray model was used to estimate the relative levels of liquid fuel spray impingement on the piston surface and maximum local equivalence ratio at SOC for each test case. Therefore, though the premixing time was shortened by higher intake pressures, the decreased emissions were understood by combined effects of enhanced fuel and air premixing quality and much improved late-cycle oxidation near the end of combustion.

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Unregulated Exhaust Emissions from Alternate Diesel Combustion Modes

Cited by 18 publications

References 3 publications

Volatility characterization of nanoparticles from single and dual-fuel low temperature combustion in compression ignition engines

Volatility characterization of nanoparticles from single and dual-fuel low temperature combustion in compression ignition engines

Volatile Organic Compounds in Exhaust Gas from Diesel Engines under Various Operating Conditions

Effects of intake pressure on particle size and number emissions from premixed diesel low-temperature combustion

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