Particle Number Emissions of a Diesel Vehicle during and between Regeneration Events

All modern diesel vehicles in Europe are equipped with diesel particulate filters (DPFs) and their particle number (PN) emissions at the tailpipe are close to ambient air levels. After the Dieselgate scandal for high NOx emissions of diesel vehicles on the road, the high PN emissions during regeneration events are on the focus. The PN emissions of a diesel vehicle on the road and in the laboratory with or without regeneration events were measured using systems with evaporation tubes and catalytic strippers and counters with lower sizes of 23, 10 and 4 nm. The tests showed significant PN levels only during engine cold starts with a big fraction of sub-23 nm particles during the first minute. After the first seconds the sub-23 nm fraction was negligible. Urea injection at the selective catalytic reduction (SCR) for NOx system did not affect the PN levels and the sub-23 nm fraction. The emissions during regeneration events were higher than the PN limit, but rapidly decreased 2-3 orders of magnitude below the limit after the regeneration. Artificially high sub-10 nm levels were seen during the regeneration (volatile artifact) at the system with the evaporation tube. The regenerations were forced every 100–350 km and the overall emissions including the regeneration events were two to four times lower than the current laboratory PN limit. The results of this study confirmed the efficiency of DPFs under laboratory and on-road driving conditions.

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Emissions of a Euro 6b Diesel Passenger Car Retrofitted with a Solid Ammonia Reduction System

Atmosphere ◽

10.3390/atmos10040180 ◽

2019 ◽

Vol 10 (4) ◽

pp. 180 ◽

Cited By ~ 8

Author(s):

Barouch Giechaskiel ◽

Ricardo Suarez-Bertoa ◽

Tero Lahde ◽

Michael Clairotte ◽

Massimo Carriero ◽

...

Keyword(s):

Catalytic Reduction ◽

Nox Reduction ◽

Cold Start ◽

Nox Emissions ◽

Passenger Car ◽

The Road ◽

Diesel Vehicles ◽

Hot Start ◽

On The Road ◽

Solid Ammonia

Nitrogen oxides (NOx) emissions from diesel vehicles are a serious environmental concern. Prior to the introduction of on-road tests at type approval, vehicle on-road NOx emissions were found many times higher than the applicable limits. Retrofitting an existing vehicle is a short/mid-term solution. We evaluated a NOx reduction retrofit system installed on a Euro 6b diesel passenger car both in the laboratory and on the road. The retrofit consisted of an under-floor SCR (selective catalytic reduction) for NOx catalyst in combination with a solid ammonia-based dosing system as the NOx reductant. The retrofit reduced NOx emissions from 25% (50 mg/km) to 82% (725 mg/km) both in the laboratory and on the road. The minimum reduction was achieved at cold start cycles and the maximum at hot start cycles. The retrofit had small effect on CO2 (fuel consumption). No ammonia emissions were detected and the N2O increase was negligible at cold start cycles, but up to 18 mg/km at hot start cycles. The results showed that the retrofit technology could be beneficial even for high emitting Euro 6b diesel vehicles.

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Solid Particle Number Emission Factors of Euro VI Heavy-Duty Vehicles on the Road and in the Laboratory

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph15020304 ◽

2018 ◽

Vol 15 (2) ◽

pp. 304 ◽

Cited By ~ 29

Author(s):

Barouch Giechaskiel

Keyword(s):

Solid Particle ◽

Particle Number ◽

Emission Factors ◽

Heavy Duty ◽

The Road ◽

On The Road ◽

Heavy Duty Vehicles

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Particle Number Emissions of Nonroad Diesel Engines of Various Ages

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4006977 ◽

2012 ◽

Vol 134 (9) ◽

Cited By ~ 1

Author(s):

Seppo Niemi ◽

Krister Ekman ◽

Pekka Nousiainen

Keyword(s):

Diesel Engines ◽

Particle Number ◽

New Technologies ◽

Fuel Injection ◽

Nox Reduction ◽

Particle Size Range ◽

Diesel Particulate ◽

Diesel Particulate Filters ◽

Particulate Filters ◽

Injection Pump

Over the last two decades, gaseous and particle mass emissions of new diesel engines have been reduced effectively and progressively in response to the emissions legislation and due to the applied new technologies. There is, however, increasing concern about whether the engine modifications, while improving combustion and reducing emissions, have increased the number emissions of ultrafine and nanoparticles. So far, emissions regulations have solely been based on particulate matter (PM) mass measurements, not on particle number. Nanoparticles, however, form a major part of the PM emissions, but they do not considerably contribute to the PM mass and cannot be seen as a problem, if only PM mass is determined. Therefore, there is increasing interest in expanding the scope of the regulations to also include particle number emissions, e.g., Euro VI for on-road engines. The PM number limit will also be enforced for nonroad engines slightly later. Thus, more information is required about the particle number emissions themselves, but also about the effects of the engine technology on them. Wall-flow diesel particulate filters reduce the particle number very effectively within the entire particle size range. Nevertheless, in order to keep the filter as small as possible and to lessen the need for regeneration, the engine-out PM number should also be minimized. If the diesel particulate filters (DPFs) could be left out or replaced by a simpler filter, there would be greater freedom of space utilization or cost savings in many nonroad applications. This might be realized in installations where the engine is tuned at high raw NOx and a selective catalytic reduction (SCR) system is adopted for NOx reduction. However, it is not self-evident that new engine technologies would reduce the PM number emissions sufficiently. In this study, particle number emissions were analyzed in several nonroad diesel engines, representing different engine generations and exploiting different emissions reduction technologies: four- or two-valve heads, exhaust gas recirculation, different injection pressures and strategies, etc. All engines were turbocharged, intercooled, direct-injection nonroad diesel engines. Most engines used common-rail fuel injection technology. Comparisons were, however, also performed with engines utilizing either a distributor-type or an in-line fuel injection pump to see the long-term development of the particle number emissions. In this paper, the PM number emissions of nine nonroad diesel engines are presented and compared. Gaseous exhaust emissions and fuel consumption figures are also provided.

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Chemical speciation of PM emissions from heavy-duty diesel vehicles equipped with diesel particulate filter (DPF) and selective catalytic reduction (SCR) retrofits

Atmospheric Environment ◽

10.1016/j.atmosenv.2008.12.040 ◽

2009 ◽

Vol 43 (11) ◽

pp. 1917-1925 ◽

Cited By ~ 76

Author(s):

Subhasis Biswas ◽

Vishal Verma ◽

James J. Schauer ◽

Constantinos Sioutas

Keyword(s):

Selective Catalytic Reduction ◽

Diesel Particulate Filter ◽

Chemical Speciation ◽

Catalytic Reduction ◽

Particulate Filter ◽

Heavy Duty ◽

Diesel Particulate ◽

Diesel Vehicles ◽

Heavy Duty Diesel

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PM Emissions from Light-Duty Diesel Vehicles Retrofitted with Diesel Particulate Filters

10.4271/2010-01-0788 ◽

2010 ◽

Cited By ~ 1

Author(s):

Qiang Wei ◽

Frank Ziegler ◽

Wolfgang Winkler

Keyword(s):

Diesel Particulate ◽

Diesel Particulate Filters ◽

Particulate Filters ◽

Diesel Vehicles ◽

Light Duty

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A Method for Measuring Particle Number Emissions from Vehicles Driving on the Road

Environmental Technology ◽

10.1080/09593332508618430 ◽

2002 ◽

Vol 23 (1) ◽

pp. 1-14 ◽

Cited By ~ 14

Author(s):

J. P. Shi ◽

R. M. Harrison ◽

D. E. Evans ◽

A. Alam ◽

C. Barnes ◽

...

Keyword(s):

Particle Number ◽

The Road ◽

On The Road

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Assessment of Gaseous and Particulate Emissions of a Euro 6d-Temp Diesel Vehicle Driven >1300 km Including Six Diesel Particulate Filter Regenerations

Atmosphere ◽

10.3390/atmos11060645 ◽

2020 ◽

Vol 11 (6) ◽

pp. 645 ◽

Cited By ~ 3

Author(s):

Victor Valverde ◽

Barouch Giechaskiel

Keyword(s):

Average Distance ◽

Short Interval ◽

Background Level ◽

Particulate Filter ◽

N2o Emissions ◽

Particulate Emissions ◽

Nox Emissions ◽

Diesel Particulate ◽

The Road ◽

On The Road

Diesel-fueled vehicles have classically had high particulate and NOx emissions. The introduction of Diesel Particulate Filters (DPFs) and Selective Catalytic Reduction for NOx (SCR) systems have decreased the Particle Number (PN) and NOx emissions, respectively, to very low levels. However, there are concerns regarding the emissions released during the periodic DPF regenerations, which are necessary to clean the filters. The absolute emission levels and the frequency of the regenerations determine the contribution of regenerations, but where they happen (city or highway) is also important due to different contributions to human exposure. In this study, we measured regulated and non-regulated emissions of a Euro 6d-temp vehicle both in the laboratory and on the road. PN and NOx emissions were similar in the laboratory and on-the road, ranging around 1010 p/km and 50 mg/km, respectively. Six regeneration events took place during the 1300 km driven, with an average distance between regeneration events of only 200 km. During regeneration events, the laboratory limits for PN and NOx, although not applicable, were exceeded in one of the two measured events. However, the on-road emissions were below the applicable not-to-exceed limits when regenerations occurred. The weighted PN and NOx emissions over the regeneration distance were approximately two times below the applicable limits. The N2O emissions were <14 mg/km and NH3 at instrument background level (<1 ppm), reaching 8 ppm only during regeneration. The results of this study indicate that due to the short interval between regenerations, studies of diesel vehicles should report the emissions during regeneration events.

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Assessment of Dust Concentrations Affecting People Working on Roadsides to Mahasarakham University

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.931-932.676 ◽

2014 ◽

Vol 931-932 ◽

pp. 676-680

Author(s):

Arika Bridhikitti ◽

Kanjana Thongsanit ◽

Sunisa Chumphuthim ◽

Patsorn Khwasui ◽

Pawadee Nabumrung ◽

...

Keyword(s):

Occupational Safety ◽

Ambient Air ◽

Quality Standard ◽

Respirable Dust ◽

Health Administration ◽

The Road ◽

On The Road ◽

Ambient Air Quality Standard ◽

High Level ◽

Dust Sampling

This study aims to assess possibility of health risk attributed to nuisance dust on people living and working on roadside areas nearby Mahasarakham University (MSU). Nuisance dust was measured during November 2012 to May 2013 covering a school semester and a school break. All samples for Ban Tha Kong Yang roadside area showed high level of ambient aerosol with size less than 10 micron and the level was exceeding the national ambient air quality standard of 0.12 mg m-3 . Approximately half of the samples taken for Ban Kham Riang also show the same result. This suggests significant dust problem in these areas and could potentially cause adverse human health effects. Results from personal respirable dust sampling show that construction worker was exposed to the highest respirable dust concentration among three occupations, including security guard and street-food cooker. The levels were significantly higher with longer time on the road and having earth moving activity nearby. Occupational exposure to respirable dust, however, was not exceeding the US Occupational Safety and Health Administration standard of 5 mg m-3.

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