Remote sensing of PM, NO, CO and HC emission factors for on-road gasoline and diesel engine vehicles in Las Vegas, NV (original) (raw)
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Journal of the Air and Waste Management Association, 2011
Fuel-based emission factors for 143 light-duty gasoline vehicles (LDGVs) and 93 heavy-duty diesel trucks (HDDTs) were measured in Wilmington, CA using a zero-emission mobile measurement platform (MMP). The frequency distributions of emission factors of carbon monoxide (CO), nitrogen oxides (NO x), and particle mass with aerodynamic diameter below 2.5 mm (PM 2.5) varied widely, whereas the average of the individual vehicle emission factors were comparable to those reported in previous tunnel and remote sensing studies as well as the predictions by Emission Factors (EMFAC) 2007 mobile source emission model for Los Angeles County. Variation in emissions due to different driving modes (idle, low-and high-speed acceleration, low-and high-speed cruise) was found to be relatively small in comparison to intervehicle variability and did not appear to interfere with the identification of high emitters, defined as the vehicles whose emissions were more than 5 times the fleet-average values. Using this definition, approximately 5% of the LDGVs and HDDTs measured were high emitters. Among the 143 LDGVs, the average emission factors of NO x , black carbon (BC), PM 2.5 , and ultrafine particle (UFP) would be reduced by 34%, 39%, 44%, and 31%, respectively, by removing the highest 5% of emitting vehicles, whereas CO emission factor would be reduced by 50%. The emission distributions of the 93 HDDTs measured were even more skewed: approximately half of the NO x and CO fleet-average emission factors and more than 60% of PM 2.5 , UFP, and BC fleet-average emission factors would be reduced by eliminating the highest-emitting 5% HDDTs. Furthermore, high emissions of BC, PM 2.5 , and NO x tended to cluster among the same vehicles.
Transportation Research Part D: Transport and Environment, 2004
Carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NO) emission factors (EFs) are measured with a commercial vehicle emissions remote sensing system (VERSS) during a large-scale vehicle exhaust emissions study in Las Vegas. Particulate matter (PM) EFs are simultaneously measured for individual vehicles with a newly developed PM-VERSS based on ultraviolet backscatter light detection and ranging (Lidar). The effectiveness of CO and HC EFs as proxy for NO and PM EFs for spark-ignition vehicles is evaluated. Poor correlations were found between EFs for pollutants on an individual vehicle basis indicating that high EFs for one or more pollutants cannot be used as a predictor of high EFs for other pollutants. Stronger functional relationships became evident after averaging the EF data in bins based on rank-order of a single pollutant EF. Low overlap between the highest 10% emitters for CO, HC, NO, and PM was found. These results imply that for an effective reduction of the four pollutants, inspection and maintenance (I/M) programs, including clean screening, should measure all four pollutants individually. Fleet average CO and HC concentrations determined by gaseous VERSS were compared with fleet average CO and HC concentrations measured at low-idle and at high-idle during local I/M tests for spark-ignition vehicles. The fleet average CO concentrations measured by I/M tests at either idle were about half of those measured by remote sensing. The fleet average high-idle HC concentration measured by I/M tests was about half of that measured by VERSS while low-idle I/M and VERSS HC average concentrations were in better agreement. For a typical vehicle trip, most of the fuel is burned during non-idle conditions. (C. Mazzoleni).
Road vehicle emission factors development: A review
Atmospheric Environment, 2013
h i g h l i g h t s < The accuracy of road emission models is directly linked to the quality of their emission factors. < Road vehicles have a large natural variability in their emission profiles. < Emission factors may have different resolution according to their intended use. < Emission modellers should combine laboratory data with real-world measurements.
Atmospheric Environment, 2008
Gas-and particle-phase pollutants were measured separately for (a) light-duty (LD) vehicles and (b) medium-duty (MD) and heavy-duty (HD) diesel trucks. Measurements were made during summer 2006 at the Caldecott Tunnel in the San Francisco Bay area as part of a continuing campaign to track changes in vehicle emissions over time. When normalized to fuel consumption, NO x emission factors were found to be 3.070.2 and 4073 g kg À1 for LD vehicles and MD/HD diesel trucks, respectively. Corresponding particulate matter (PM 2.5) emission factors were 0.0770.02 and 1.470.3 g kg À1. The ratio of particulate black carbon to organic mass (BC/OM) for LD vehicles was 0.7170.15. For diesel trucks, BC/OM was 271, indicating that PM 2.5 was dominated by BC. Results from 2006 are compared to similar measurements made at the same site in 1997. For LD vehicles, NO x and PM 2.5 emission factors decreased by 6773% and 36717%, respectively. Corresponding decreases for diesel trucks were 3079% for NO x and 48712% for PM 2.5. The ratio of HD to LD emission factor for NO x increased from 671 to 1371 between 1997 and 2006, which indicates an increase in the relative importance of diesel trucks as a source of NO x emissions. The absorption, scattering, and extinction cross-section emission factors parameters relevant to climate change and atmospheric visibility, were an order of magnitude higher for diesel trucks than LD vehicles. Single-scattering albedo, measured at l ¼ 675 nm, was 0.3170.06 and 0.2070.05 for LD vehicle and diesel truck PM emissions, respectively.
On-road emissions of CO, CO2 and NOX from four wheeler and emission estimates for Delhi
Journal of Environmental Sciences, 2016
This study presents the emission factor of gaseous pollutants (CO, CO 2 , and NO X) from on-road tailpipe measurement of 14 passenger cars of different types of fuel and vintage. The trolley equipped with stainless steel duct, vane probe velocity meter, flue gas analyzer, Nondispersive infra red (NDIR) CO 2 analyzer, temperature, and relative humidity (RH) sensors was connected to the vehicle using a towing system. Lower CO and higher NO X emissions were observed from new diesel cars (post 2010) compared to old cars (post 2005), which implied that new technological advancement in diesel fueled passenger cars to reduce CO emission is a successful venture, however, the use of turbo charger in diesel cars to achieve high temperature combustion might have resulted in increased NO X emissions. Based on the measured emission factors (g/kg), and fuel consumption (kg), the average and 95% confidence interval (CI) bound estimates of CO, CO 2 , and NO X from four wheeler (4W) in Delhi for the year 2012 were 15.7 (1.4-37.1) , 6234 (386-12,252) , and 30.4 (0.0-103) Gg/year, respectively. The contribution of diesel, gasoline and compressed natural gas (CNG) to total CO, CO 2 and NO X emissions were 7:84:9, 50:48:2 and 58:41:1 respectively. The present work indicated that the age and the maintenance of vehicle both are important factors in emission assessment therefore, more systematic repetitive measurements covering wide range of vehicles of different age groups, engine capacity, and maintenance level is needed for refining the emission factors with CI.
Science of The Total Environment, 2019
Road traffic is one of the main sources of particulate matter in the atmospheric environment. Notwithstanding its significance, there are noteworthy challenges in quantitative assessment of its contribution to the concentrations of airborne. This study reports on the characterization and quantification of PM 2.5 emissions and PAHs concentration in PM 2.5 from the exhausts of on-road diesel vehicles with various accumulated mileages in Kaohsiung City, Taiwan. Urban areas could be a subject matter not just in connection to deprived air quality, but similarly to pollution of other significant environmental media by air contaminants. To that end, our study intends to estimate the PM 2.5 emissions from diesel vehicles using diesel fuels and to analyze the PM 2.5 emissions and PAHs concentration in PM 2.5. In this study, particulate matters (PM 2.5) were characterized and quantified from a place impacted by diesel vehicles fueled with diesel in Kaohsiung City, Taiwan. The tested diesel vehicles with various accumulated mileages overs the model year comprising of the vehicles registered from 1984 to 2012 from different manufacturers (or brands) ranging from 8733 to 965,026 km (average 445,433 km) accumulative mileages. Exhaust constituents include CO, NOx, PM 2.5 and particle phase PAHs. The concentrations of twenty-one (21) priority polycyclic aromatic hydrocarbons (PAHs) were studied in the samples by their relationship with atmospheric PM 2.5. However, in relations to cumulative mileages, lower cumulative mileage (mileage b20,000 km) has the lowest CO and NOx emission factors. The mileage ranged from 20,001 to 30,000 km had an increased CO and NOx emission factors, respectively. Interestingly, with the increased high number of mileages ranged from 30,001 to 50,000 km, CO and NOx emission factor was observed to be declining, respectively. This could be attributed to the technological changes on new diesel vehicle models. But nonetheless, the trend of CO
Quantification of motor vehicle emission factors from on road measurements
2003
Assessment and prediction of the impact of vehicular traffic emissions on air quality and exposure levels requires knowledge of vehicle emission factors. The aim of this study was quantification of emission factors from an on road, over twelve months measurement program conducted at two sites in Brisbane: 1) freeway type (free flowing traffic at about 100 km/h, fleet dominated by small passenger cars-Tora St); and 2) urban busy road with stop/start traffic mode, fleet comprising a significant fraction of heavy duty vehicles-Ipswich Rd. A physical model linking concentrations measured at the road for specific meteorological conditions with motor vehicle emission factors was applied for data analyses. The focus of the study was on submicrometer particles; however the measurements also included supermicrometer particles, PM 2.5 , carbon monoxide, sulfur dioxide, oxides of nitrogen. The results of the study are summarised in this paper. In particular, the emission factors for submicrometer particles were 6.08 x 10 13 and 5.15 x 10 13 particles per vehicle-1 km-1 for Tora St and Ipswich Rd respectively and for supermicrometer particles for Tora St, 1.48 x 10 9 particles per vehicle-1 km-1. Emission factors of diesel vehicles at both sites were about an order of magnitude higher than emissions from gasoline powered vehicles. For submicrometer particles and gasoline vehicles the emission factors were 6.08 x 10 13 and 4.34 x 10 13 particles per vehicle-1 km-1 for Tora St and Ipswich Rd, respectively, and for diesel vehicles were 5.35 x 10 14 and 2.03 x 10 14 particles per vehicle-1 km-1 for Tora St and Ipswich Rd, respectively. For supermicrometer particles at Tora St the emission factors were 2.59 x 10 9 and 1.53 x 10 12 particles per vehicle-1 km-1 , for gasoline and diesel vehicles, respectively.
Transportation Research Part D: Transport and Environment, 2009
20 21 Vehicle emissions estimates are needed at high spatial and temporal resolution to estimate near-22 roadway air quality and human exposures. The MOBILE6 emission factor model is based on 23 transient test cycles of less than 65 mph. Correction factors for high speed and constant speed 24 are developed based on vehicle-specific power (VSP)-based modal models for light duty 25 gasoline vehicles, using data obtained from portable emission measurement systems (PEMS). At 26 80 mph versus 65 mph, the estimated average emission rates are greater by 30, 20, 80, and 10 27 percent for NO x , HC, CO, and CO 2 , respectively. The ratio of constant to average of transient 28 speed emission rates range from 0.49 to 0.94 for NO x at speeds of 20 mph and 80 mph, 29 respectively. The high speed and constant speed correction factors are applied to estimate 30 vehicle emissions for a freeway segment that includes vehicle cruising speeds between 65 and 80 31 mph. The potential error for not accounting for constant speed operation on a short segment of 32 highway could be as high as 49 percent at moderate speed and 24 percent at high speed. 33 34
Emission Factors of CH4 and CO2 Emitted from Vehicles
2016
The study of the Emission Factors (EF) of methane (CH4) and Carbon Dioxide (CO2) emitted from vehicle exhaust is the study of greenhouse gases that are crucial to climate change. These gases are part of a fuel known as Compressed Natural Gas (CNG) or as Natural Gas for Vehicles (NGV) in Thailand. This fuel is used as an alternative to oil, which has decreased the amount of gasoline and diesel oil used in the transportation sector of Thailand. This study used different types of cars that were tested on a chassis dynamometer with a Bangkok driving cycle to measure the emissions of CH4 and CO2 and then to calculate the averages of EF-CH4 and EF-CO2, which are associated with speed and fuel consumption, respectively. This study was conducted in 3 vehicle types that are actually used in Thailand, namely, Heavy Duty Diesel Vehicles (HDDV), Light Duty Diesel Vehicles (LDDV) and Light Duty Gasoline Vehicles (LDGV). Our results showed that of the three vehicle types, HDDV produced the highes...