Emissions gasoline powered engines

Hadnagy W, Seemayer NH. 1988. Cytotoxic and genotoxic effects of extract of particulate emission from a gasoline-powered engine. Environ Mol Mutagen 12 385- 396. 

Hadnagy W, Seemayer NH. 1989. Genotoxicity of particulate emissions from gasoline-powered engines evaluated by short-term bioassays. Experimental Pathology 37 43-50. 

By gasoline powered engines, NOx emissions increase with average speed (Pearce, 1986 -Joumard, 1986). 

A major difference between diesel engines and gasoline powered engines is that the potential for controlling hydrocarbons in diesel exhaust through exhaust catalysts is very poor. The most that can be expected is some form of trap to contain diesel particulates. This may also be effective in controlling PNA, since a substantial part of the PNA emission from diesels is associated with the solid material. 

Nevertheless, secondary measures are mostly still needed to reduce exhaust emissions of cars to meet current emission standard in most countries. These so-called end-of-pipe solutions are based on the catalytic conversion of all HCs, CO and NO (three-way catalyst). The success of the monolithic catalytic converter (which has a lower pressure drop than a fixed bed) is up to now limited to gasoline powered engines. However, in recent years progress has been made in the development of catalytic filters for the cleaning of exhaust gas (e.g., particulate matter) from diesel engines. 

Anthropogenic sources of NgO include adipic and nitric acid production, fossil fuel and biomass combustion, land cultivation, and vehicle emissions. " NgO emissions from gasoline-powered engines have been related to the aging of three-way catalysts (TWCs) and NgO is also emitted as a by-product of Pt-based prototypic catalysts for the selective catalytic reduction (SCR) of NO with hydrocarbons in diesel engine exhausts. ... 

Transportation accounts for about one-fourth of the primary energy consumption in the United States. And unlike other sectors of the economy that can easily switch to cleaner natural gas or electricity, automobiles, trucks, nonroad vehicles, and buses are powered by internal-combustion engines burning petroleum products that produce carbon dioxide, carbon monoxide, nitrogen oxides, and hydrocarbons. Efforts are under way to accelerate the introduction of electric, fuel-cell, and hybrid (electric and fuel) vehicles to replace sonic of these vehicles in both the retail marketplace and in commercial, government, public transit, and private fleets. These vehicles dramatically reduce harmful pollutants and reduce carbon dioxide emissions by as much as 50 percent or more compared to gasoline-powered vehicles. 

Natural gas (NG) consists of 85-95% methane (CH ), which is the simplest hydrocarbon. NG is the cleanest burning alternative fuel. Exhaust emissions from NG vehicles are much lower than those from gasoline-powered vehicles. Combustion of NG reduces carbon dioxide content compared with diesel, but the lost efficiency when the Otto process is used means that carbon dioxide emissions increase. All in all combustion of NG in a gasoline engine gives rise to about as much carbon dioxide as the combustion of diesel in a diesel engine, measured in units of energy. 

One of the latest attempts to reduce carbon emissions in cars is the development of the gasoline-electric hybrid vehicle, or hybrid car. A hybrid car uses two sources of energy a traditional, fossil-fuel-powered engine and a battery that stores electrical energy. A hybrid car can burn fossil fuels and run on a traditional engine or, at other times, the car runs on clean electric power. Because it runs partly on electricity, a hybrid emits much less atmospheric carbon dioxide and other pollutants. 

With fuels used in internal combustion engines, the reaction of eq 2 is the major cause of nitrogen oxides emissions. Of course, the amount of carbon monoxide, hydrocarbons and nitrogen oxides that are emitted is dependent on the detailed composition of the fuel as well as on the way the combustion is performed. But as an order of magnitude, the exhaust gas of a gasoline-powered spark-ignited internal combustion engine will have the composition shown in Fig. 1. 

In this paper we concentrate upon fuel characteristics giving particular attention to the aromatic fraction of fuels used in gasoline and diesel engines. A principal objective is to find, if possible, which type of aromatic could be excluded or added in order to lower PAH emissions and consequentely reduce carcinogenicity while maintaining the beneficial properties of such aromatics. To accomplish this objective we will deal separately with the major motive power engines namely, gasoline and diesel. 

Fuel cells will soon be a viable alternative to the gasoline-powered internal combustion engine, and, beyond 2010, they can be expected to be the primary automotive power source. Buses are fuel cell-powered, and cars are next. A motivation driving fuel cell development for automotives is tougher emission standards required in several eastern states and California. Another motivation is to enhance national security with energy independence. U. S. automobile manufacturers plan to have fuel cell-powered cars on the market by 2004. Thermoplastic elastomers coated with a platinum catalyst compose the fuel cell membrane electrode, referred to in Sec. 10.3.1.3. 

The Diesel engine has excessive emission of smoke and odor from aldehydes and oxygenated aromatics, which are not regulated at this moment. It is approximately 50% larger and heavier than a gasoline engine of the same horse power. However, it does have the virtue of better fuel economy and easier maintenance. 

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