Automotive exhaust, particulate

Melton, C. W., R. I. Mitchell, D. A. Trayser, and J. F. Foster. Chemical and Physical Characterization of Automotive Exhaust Particulate Matter in the Atmos-... 

Secondary particulates were found to account for about 8% and automotive exhaust about 10% of the annual average mass. 

More recently Cass, Boone and Macias constructed a very detailed carbon inventory for Metropolitan Los Angeles in order to estimate the amount of primary elemental and organic carbon in this urban area ( ). Over 50 source types were included in this emission Inventory. A particulate lead emission inventory was also constructed and used as a tracer for primary automotive exhaust. They compared the ratio of organic carbon to elemental carbon and lead from the emission estimates to that measured in the atmosphere during winter mornings. In that study the sampling time and location were chosen in order to measure... 

Emission studies show that lead is only a small part of the automotive pollution problem. Prior to control, hydrocarbon emissions were more than 40 times and the oxides of nitrogen emissions more than 15 times the emission of the lead compounds. Obviously, however, legislation will result in the eventual elimination of lead from gasoline. The removal of lead, besides eliminating a possible toxic pollutant, simplifies the problem of handling other automotive exhaust pollutants in that catalytic exhaust chambers perform much better in the absence of lead contaminant. All emission standards become particularly severe in 1975 and 1980. The particulate standards are equivalent to 1 gram Pb/gal in 1975 and 0.3 gram Pb/gal in 1980. Since the particulates include all solid materials, tolerable lead levels will be less than indicated above. 

Graskow BR, Kittelson DB, Abdul-Khaleek IS, Ahmadi MR, Morris JE (1998) Characterization of exhaust particulate emissions from a spark ignition engine. Society of Automotive... 

In addition to ablation products such as nickel, copper, and iron now commonly present in exhaust, there is the potential occurrence in exhaust particulate of metals in use or considered for use as catalyst materials. Their detection would depend upon both increased use and/or increased analytical sensitivity. Efforts to quantify by routine methods emissions of platinum and palladium, now in widespread use in the oxidation catalyst, have failed to substantiate the presence of these metals in exhaust. An emission factor of 3.1 X 10" g/mile for platinum has been estimated (53). Other metals which have been considered for use in automotive catalysts include ruthenium and vanadium. 

Particulate Emissions in Automotive Exhaust, EPA Contract No. CPA-22-69-145, Dow Chemical Co. (1970). 

PAHs, ketones, and quinones in particulates < 2 pm from automotive exhaust (Rogge et al. 1993), and oxygenated PAHs including ketones and quinones from an urban aerosol-size fractionation... 

Ni troazabenzofa] pyrenes in airborne particulate matter and automotive exhaust (Sera et al. 1994) ... 

Dust from paved and unpaved roads is the most predominant source in Portland. Accurate emissions data is critical to the model s ability to account for all of the measured mass, as well as to the development of a successful strategy. Although the CMB model cannot distinguish between dust emissions from paved and unpaved roads, it can typically assign total dust impacts to within a 5-6% uncertainty. Leaded automotive tailpipe exhaust was selected because it can be accurately estimated by CMB and is the third most abundant contributor to the annual particulate mass, after road dust and vegetative burning. 

Nowadays automobile prevails across the globe as the most popular and important mode of transportation in our daily fife. About 50 million cars are produced each year, and totally over 700 million cars are being used worldwide. Thus, the application of automotive catalysts for detoxifying the pollutants, such as carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx) and particulate matter (PM) in the exhaust gases is absolutely indispensable in every vehicle. 

Exhaust emission legislation has become more and more stringent over the last years, demanding for lower engine raw emissions and more efficient exhaust converters. Simultaneous low emission limits for different species, e.g. PM and NOx, lead to the development of combined aftertreatment systems, consisting of different catalyst technologies and particulate filter. Simulation can make a considerable contribution to shorten the time and lower the cost of the system development. In this publication, the current status of exhaust aftertreatment simulation tools used in automotive industry is reviewed. The developed models for DOC with HC adsorption, NSRC and catalyst for SCR of NOx by NH3 (urea) were included into the common simulation environment ExACT, which enables simulation of complete combined exhaust aftertreatment systems. 

Today s automotive engines emit a number of toxic pollutants CO, unburned fuel, partially oxidized fuel, hot particulates, and nitrogen oxides (NO, N20, and N02, collectively termed NOx). Table 4.2 shows the typical concentrations of the exhaust gas constituents of gasoline engines [108], together with the legal emission limits set by the EU in 2005 [109]. 

Figure 99. Amount and composition of particulates in the exhaust gas of a heavy duty DI diesel engine at various engine operation conditions in the AVL-8-mode engine test cycle. Reprinted with permission from ref [68], 1991 Society of Automotive Engineers, Inc.

Ludke C and Hoeemann E (1996) Analysis of particulates in automotive catalyst exhausts by ETV-ICPMS. Fresenius J Anal Chem 355 261-263. 

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