Vehicle exhaust/emissions

Table 8. California Light-Duty Vehicle Exhaust Emission Standards...

EEC Directive on motor vehicle exhaust emission tests... 

The generation of arr pollutants, including VOC s, from automotive vehicles was identified to come from two principal sources vehicle exhaust emissions, and fuel system evaporative emissions [4], Evaporative emissions are defined as the automotive fuel vapors generated and released from the vehicle s fuel system due to the interactions of the specific fuel in use, the fuel system characteristics, and environmental factors. The sources of the evaporative emissions are discussed below and, as presented m the remainder of this chapter, control of these evaporative emissions are the focus of the application of activated carbon technology in automotive systems. 

Noble, W. M. The Relation of Plant Damage to Fuel Composition. Paper Presented at the Joint Research Conference on Motor Vehicle Exhaust Emissions and Their Effects, Dec. 5, 1%1, University of California, Los Angeles. 11 pp. 

FIGURE 16.33 Distribution of exhaust CO and hydrocarbon (HC) vehicle exhaust emissions as a function of model year in the United States (adapted from Stephens, 1994). 

Cadle, S. H., and R. D. Stephens, Remote Sensing of Vehicle Exhaust Emissions, Enciron. Sci. Technoi, 28, 258A-264A(1994). 

Hoekman, S. K Speciated Measurements and Calculated Reactivities of Vehicle Exhaust Emissions from Conventional and Reformulated Gasolines, Environ. Sci. Technol., 26, 1206-1216 (1992). 

Hough, A. M and C. Reeves, Photochemical Oxidant Formation and the Effects of Vehicle Exhaust Emission Controls in the U.K. The Results from 20 Different Chemical Mechanisms, Atmos. Environ., 22, 1121-1135 (1988). 

Stephens, R. D., Remote Sensing Data and a Potential Model of Vehicle Exhaust Emissions, J. Air Waste Manage. Assoc., 44, 1284-1292 (1994). 

Promoters are added to Pt catalysts because the promoted catalyst with modified electronic properties leads to a decrease in the activity for coke formation and also in the rate of metal sintering. Several promoted systems have been reported in the literature including for environmnetal pollution (vehicle exhaust emission) control and some are summarized here. 

Ce02-supported noble-metal catalysts such as Pt, Pd and Rh are of interest because of their importance in the so-called three-way converter catalysts (TWC), designed to reduce emissions of CO, NOx and uncombusted hydrocarbons in the environment and to purify vehicle-exhaust emissions. Such catalysts are also of current interest in steam reforming of methane and other hydrocarbons. Conventional practical catalysts for steam reforming consist of nickel supported on a ceramic carrier with a low surface area and are used at high temperatures of 900 C. This catalyst suffers from coke formation which suppresses the intrinsic catalyst activity. Promoters such as Mo are added to suppress coke formation. Recently, Inui etal(l991) have developed a novel Ni-based composite... 

In addition to very low exhaust emissions, CNG vehicles also have the advantage of no evaporative emissions or running loss emissions9 caused by the fuel. As vehicle exhaust emissions are reduced to meet the most stringent standards, running loss emissions become more important. 

In order to protect health and the environment, vehicle exhaust emission standards will continue to be tightened in the EU, and increasing numbers of vehicles will be fitted with the latest exhaust emission-control technologies. By 2020 about one quarter of the total mileage in EU-27 is likely to be covered by cars and trucks certified to Euro 5/V, and more than half by vehicles certified to Euro 6/VI, according to scenarios examined in the LIFE + EC4MACS project (www. ec4macs.eu). 

As previously mentioned, in the big urban centres of Eastern Mediterranean Basin the concentrations of PM10 are frequently above the threshold limit values. However, the quantification of vehicles exhaust emissions suggests that solely the latter cannot possibly explain the observed high concentrations. 

Owing to their greater exposure to motor vehicle exhaust emissions, it is possible that fatty foods on sale at shops attached to petrol stations or at stalls and shops in busy roads could contain higher concentrations of aromatic hydrocarbons than similar foods on sale at other shops. A study in Germany found that concentrations of benzene and toluene were higher in retail packs from petrol stations on busy roads than from petrol stations in rural areas.15 It also found that retail packs from shops in busy roads contained higher concentrations of benzene, toluene, xylenes and ethylbenzene than retail packs from shops in residential areas. 

Gas analytical instruments for vehicle exhaust emission surveillance, evidential breath alcohol analysis in road traffic and calorific value determination of fuel gases are subject to legal control and require type approval and initial and subsequent verification. The national standards required in this part of gas analysis are provided by BAM. PTB uses in-house standards prepared by dynamic blending to ensure traceability of its type approval... 

Gordon Larson who succeeded McCabe continued to reduce the emissions of refineries and other industries. He also undertook the control of emissions from open dump burning and backyard incinerators and made the initial contacts with the automobile industry to control motor vehicle exhaust emissions. However, in this drive to control the proved main sources of air pollution, Larson was opposed by the petroleum, chemical, and other industries, and primarily the individual citizen with his backyard incinerator. 

Respirable particulate or gaseous forms of lead may be inhaled. Sources include cigarette smoke vehicle exhaust emissions from municipal waste incinerators, iron and steel plants, smelting and refining operations, lead acid battery manufacturing facilities, and sandblasting and burning of surfaces coated with lead paint. Particulate air emissions may eventually deposit and contaminate the soil. 

EXPOSURE ROUTES ingestion inhalation dermal contact wastewater fugitive emissions during its production and use as a chemical intermediate vehicle exhaust emissions... 

A. Gorse, J.D. Benson, L.J. Painter, V.R. Bums, R.M. Reuter, A.M. Hochlauser, B.H. Ripon "Toxic Air Pollutant Vehicle Exhaust Emissions with Reformulated Gasolines", SAE Teclmical Paper 912324. 

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