Impact of Oxygenated Gasoline Use on California Light-Duty Vehicle Emissions

Kirchstetter, Thomas W.; Singer, Brett C.; Harley, Robert A.; Kendall, Gary R.; Chan, Waymond

doi:10.1021/es950406p

Cited by 165 publications

(165 citation statements)

References 13 publications

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“…In both studies, the magnitude of near-traffic effects appeared to be more pronounced for NO X . We hypothesize that this results because NO X emissions from motor vehicles are almost entirely in the form of NO (Kirchstetter et al, 1996). NO reacts quickly with ozone to form NO 2 , but there may not always be enough ozone to titrate all of the emitted NO during the short period of transit between a freeway and a nearby site.…”

Section: Discussionmentioning

confidence: 99%

Passive measurement of nitrogen oxides to assess traffic-related pollutant exposure for the East Bay Children's Respiratory Health Study

Singer

2004

Atmospheric Environment

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The East Bay Children's Respiratory Health Study is examining associations between trafficrelated pollutant exposures and respiratory health among children who reside and attend schools at varied proximity to northern California freeways. Chronic exposures are being inferred from outdoor pollutant concentrations at neighborhood schools. This paper reports primarily weeklong integrated NO 2 and NO X concentrations measured with passive samplers placed outside at ten elementary schools during 14 weeks in spring and 8 weeks in fall 2001. Measurements were also made outside selected student residences to examine spatial variability within three school neighborhoods. Regional concentrations of NO 2 and NO X varied widely from week to week.School site data were normalized to measurements at a nearby regional monitoring station to facilitate analysis of relative pollutant exposures at the neighborhood schools. Normalized concentrations occurred at a school located directly adjacent to a major freeway and a shopping center. In this case, normalized NO 2 and NO X were ~60% and ~100% higher than regional background levels. At three schools within 130-230 m downwind of a freeway, normalized NO 2 and NO X were ~20-30% and ~50-80% higher than regional levels. Validation testing of the passive samplers indicated precision of better than 5% for both NO 2 and NO X when samplers were deployed outside for one-week periods. Passive sampler results agreed with co-located chemiluminescence measurements to within 8% for NO 2 and 3% for NO X .

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Section: Discussionmentioning

confidence: 99%

Passive measurement of nitrogen oxides to assess traffic-related pollutant exposure for the East Bay Children's Respiratory Health Study

Singer

2004

Atmospheric Environment

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“…7 EMFAC 7F correctly predicted the VOC/NO X ratio but still underpredicted the CO/NO X ratio by a factor of 1. 8 Since inventories of vehicle emissions are so uncertain, development of an independent method of calculating the MVEI has been identified as a high priority for air quality research.…”

Section: Introductionmentioning

confidence: 88%

A Fuel-Based Motor Vehicle Emission Inventory

Singer¹,

Harley

1996

Journal of the Air & Waste Management Association

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104

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A fuel-based methodology for calculating motor vehicle emission inventories is presented. In the fuel-based method, emission factors are normalized to fuel consumption and expressed as grams of pollutant emitted per gallon of gasoline burned. Fleet-average emission factors are calculated from the measured on-road emissions of a large, random sample of vehicles. Gasoline use is known at the state level from sales tax data, and may be disaggregated to individual air basins. A fuel-based motor vehicle CO inventory was calculated for the South Coast Air Basin in California for summer 1991. Emission factors were calculated from remote sensing measurements of more than 70,000 in-use vehicles. Stabilized exhaust emissions of CO were estimated to be 4400 tons/day for cars and 1500 tons/day for light-duty and medium-duty trucks, with an estimated uncertainty of ±20% for cars and ±30% for trucks. Total motor vehicle CO emissions, including incremental start emissions and emissions from heavy-duty vehicles were estimated to be 7900 tons/day. Fuelbased inventory estimates were greater than those of California's MVEI 7F model by factors of 2.2 for cars and 2.6 for trucks. A draft version of California's MVEI 7G model, which includes increased contributions from high-emitting vehicles and off-cycle emissions, predicted CO emissions which closely matched the fuel-based inventory. An analysis of CO mass emissions as a function of vehicle age IMPLICATIONSThe fuel-based methodology presented in this study may be used to calculate a motor vehicle emission inventory for any geographic area for which emissions data are available. The fuel-based approach requires fuel use data, which is obtained from state tax records, and onroad emissions data, which are becoming more available as remote sensing devices are used in Inspection & Maintenance programs around the country. Currently, the fuel-based method may be used to verify official emission inventories of CO. With further development of the methodology and advances in remote sensing capabilities for NOx and HC, the fuel-based approach could become the standard emission inventory methodology.revealed that cars and trucks which were ten or more years old were responsible for 58% of stabilized exhaust CO emissions from all cars and trucks.

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“…On-road vehicle measurements comparing reformulated fuel (containing MTBE) to conventional gasoline (without MTBE) have shown net decreases in VOCs, benzene, NO x , and CO emissions. 12 The most prominent effect of oxygenated fuels is on CO emissions. NO x emissions decrease when MTBE is used in LO gasoline, but increases with the regular gasoline.…”

Section: Methodsmentioning

confidence: 99%

Effect of Methyl Tertiary Butyl Ether Concentrations on Exhaust Emissions from Gasoline Used in the Metropolitan Area of Mexico City

Schifter

Díaz

Avalos

et al. 2000

Journal of the Air & Waste Management Association

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In this work, the primary objective was to assess the impact of oxygenated fuel on the exhaust emissions from an important fraction of vehicles in the Metropolitan Area of Mexico City (MAMC). The results aim to provide information on the actual effect of MTBE on a fleet that represents more than 60% of the in-use vehicles in the MAMC. Ten vehicles were tested with a low-octane base gasoline, and 10 more with a regular-grade unleaded base gasoline. Three MTBE concentrations, 5, 10, and 15 vol %, were tested following the U.S. Federal Test Procedure (FTP). CO, total HC, and NO x from the exhaust gases were quantitatively evaluated and also characterized for FTP speciated organic emissions. From this data, the O 3 -forming potential of the fuels was calculated. Results show that for the fleet using low-octane gasoline, the addition of 10% MTBE substantially reduced CO emissions, but total HC concentration in the exhaust showed a modest decrease. For the regular gasoline, the 10% MTBE blend seemed to be the best choice, but there was not a significant decrease in emissions. The specific reactivity of each fuel, expressed in grams of O 3 per gram of nonmethane organic gases, increased with MTBE concentration in both cases. This result is important to IMPLICATIONS Oxygenated gasoline has been used as an air quality control strategy to reduce ambient CO concentrations in the MAMC. MTBE use is being phased out or cut back in the United States and other countries, due to a range of health and environmental concerns. The potential for the phaseout to spread to Mexico is significant. Removal of the oxygenate from Mexican gasoline would likely result in a deterioration of air quality. In this work, the primary objective was to assess the actual impact of oxygenated fuel on the exhaust emissions of a representative fraction of vehicles in the MAMC. The O 3 -forming potential values of the HCs from the exhaust composition are high, so care must be taken to decide which blend is the least polluting.consider, especially for a region like Mexico City, which has high atmospheric O 3 concentrations. INTRODUCTIONFuel composition and characteristics play an important role in engine design and emissions performance. The composition and properties of gasoline and diesel fuel can significantly affect vehicle emissions. Although the relationships among fuel properties, engine technologies, and exhaust emissions are complex, changes in one fuel characteristic may lower emissions of one pollutant but increase those of another. For example, decreasing the aromatics content in gasoline lowers CO and HC emissions but increases NO x emissions. In some cases, engines in different vehicle classes respond quite differently to changes in fuel properties.

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Impact of Oxygenated Gasoline Use on California Light-Duty Vehicle Emissions

Cited by 165 publications

References 13 publications

Passive measurement of nitrogen oxides to assess traffic-related pollutant exposure for the East Bay Children's Respiratory Health Study

Passive measurement of nitrogen oxides to assess traffic-related pollutant exposure for the East Bay Children's Respiratory Health Study

A Fuel-Based Motor Vehicle Emission Inventory

Effect of Methyl Tertiary Butyl Ether Concentrations on Exhaust Emissions from Gasoline Used in the Metropolitan Area of Mexico City

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