Details:

Creators:
Frey, H. Christopher ; Rasdorf, William J. ; Kim, Kangwook ; Pang, Shih-Hao ; Lewis, Phil ; ... More +
Frey, H. Christopher ; Rasdorf, William J. ; Kim, Kangwook ; Pang, Shih-Hao ; Lewis, Phil ; Abolhassani, Saeed Less -
Corporate Creators:
North Carolina State University. Department of Civil, Construction, and Environmental Engineering
Corporate Contributors:
North Carolina. Dept. of Transportation. Research and Analysis Group
Subject/TRT Terms:
[+]
Air--Pollution--North Carolina Air Pollution Construction Equipment Construction Equipment--North Carolina Construction Equipment--Testing Testing
Publication/ Report Number:
FHWA/NC/2006-55
Resource Type:
Tech Report
Geographical Coverage:
North Carolina
Edition:
Final report; July 2005-June 2007.
Corporate Publisher:
North Carolina. Department of Transportation. Research and Analysis Group
Abstract:
Field data for in-use fuel consumption and emission rates were collected for 15 nonroad vehicles using a portable emission

measurement system (PEMS). Each vehicle, including 5 backhoes, 4 front end loaders, and 6 motor graders, were tested

once on petroleum diesel and once on B20 biodiesel. The vehicles included different model years and thus represent a

variety of engine certification tiers. A methodology was developed for study design, field data collection, data screening and

quality assurance, data analysis, and benchmarking of the data. The average rate of loss of data due to data quality issues was

6.9%. On average, over 3 hours of valid data were collected in each test. Time-based emission factors were found to

increase monotonically with respect to engine manifold absolute pressure. Fuel-based emission factors were mainly sensitive

to differences between idle and non-idle engine operation. Typical duty cycles were quantified in terms of frequency

distributions of manifold absolute pressure (MAP) and used to estimate cycle average emission factors. On average, the use

of B20 instead of petroleum diesel lead to an insignificant 1.8% decrease in NO emission rate and significant decreases of 18,

26, and 25% for opacity, HC, and CO, respectively. Emission rates were also found to decrease significantly when

comparing newer, higher tier vehicles to lower ones. Fuel use rate, and NO, HC, and CO emission factors, were found to be

of similar magnitude as independent benchmark data. An emissions inventory was developed for these vehicles. The current

fuel mix of B20 and petroleum diesel is estimated to produce 0.4 to 6.4 percent lower emissions, depending on the pollutant,

than usage of 100 percent petroleum diesel. If NCDOT were to use 100% B20 in the same vehicles, then additional

reductions in emissions of each pollutant would be approximately 2.0% to 36.9% lower than for the current fuel mix of B20

and petroleum diesel. Although higher tier engines have lower emissions factors for each pollutant than lower tier engines,

their annual average emissions tend to be higher because of greater utilization. Specific recommendations are made for

future work, including expansion of the use of B20 to further reduce tailpipe emissions in the NCDOT inventory,

replacement of older vehicles with newer ones, field data for larger sample sizes of vehicles for each Tier in order to improve

confidence in the emissions factors and inventories, assessment of Tier 4 vehicles as they become available using improved

instrumentation, evaluation of fuel formulations, evaluations of other vehicle types, and others.


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:93481a7f3ef49eeb5c8ec396ca290759a820614a707270868cbd85bdf159c19f
Download URL:
https://rosap.ntl.bts.gov/view/dot/17477/dot_17477_DS1.pdf
File Type:

Supporting Files

• No Additional Files

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