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Diesel engine

About: Diesel engine is a(n) research topic. Over the lifetime, 51385 publication(s) have been published within this topic receiving 596388 citation(s). The topic is also known as: compression-ignition engine & diesel.

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Journal ArticleDOI
Abstract: In this article, the status of fat and oil derived diesel fuels with respect to fuel properties, engine performance, and emissions is reviewed The fuels considered are primarily the methyl esters of fatty acids derived from a variety of vegetable oils and animal fats, and referred to as biodiesel The major obstacle to widespread use of biodiesel is the high cost relative to petroleum Economics of biodiesel production are discussed, and it is concluded that the price of the feedstock fat or oil is the major factor determining biodiesel priceBiodiesel is completely miscible with petroleum diesel fuel, and is generally tested as a blend The use of biodiesel in neat or blended form has no effect on the energy based engine fuel economy The lubricity of these fuels is superior to conventional diesel, and this property is imparted to blends at levels above 20 vol% Emissions of PM can be reduced dramatically through use of biodiesel in engines that are not high lube oil emitters Emissions of NOx increase significantly for both neat and blended fuels in both two- and four-stroke engines The increase may be lower in newer, lower NOx emitting four-strokes, but additional data are needed to confirm this conclusion A discussion of available data on unregulated air toxins is presented, and it is concluded that definitive studies have yet to be performed in this area A detailed discussion of important biodiesel properties and recommendations for future research is presented Among the most important recommendations is the need for all future studies to employ biodiesel of well-known composition and purity, and to report detailed analyses The purity levels necessary for achieving adequate engine endurance, compatibility with coatings and elastomers, cold flow properties, stability, and emissions performance must be better defined

1,810 citations

Journal ArticleDOI
Abstract: Fossil fuel resources are decreasing daily. Biodiesel fuels are attracting increasing attention worldwide as blending components or direct replacements for diesel fuel in vehicle engines. Biodiesel fuel typically comprises lower alkyl fatty acid (chain length C14–C22), esters of short-chain alcohols, primarily, methanol or ethanol. Various methods have been reported for the production of biodiesel from vegetable oil, such as direct use and blending, microemulsification, pyrolysis, and transesterification. Among these, transesterification is an attractive and widely accepted technique. The purpose of the transesterification process is to lower the viscosity of the oil. The most important variables affecting methyl ester yield during the transesterification reaction are the molar ratio of alcohol to vegetable oil and the reaction temperature. Methanol is the commonly used alcohol in this process, due in part to its low cost. Methyl esters of vegetable oils have several outstanding advantages over other new-renewable and clean engine fuel alternatives. Biodiesel fuel is a renewable substitute fuel for petroleum diesel or petrodiesel fuel made from vegetable or animal fats; it can be used in any mixture with petrodiesel fuel, as it has very similar characteristics, but it has lower exhaust emissions. Biodiesel fuel has better properties than petrodiesel fuel; it is renewable, biodegradable, non-toxic, and essentially free of sulfur and aromatics. Biodiesel seems to be a realistic fuel for future; it has become more attractive recently because of its environmental benefits. Biodiesel is an environmentally friendly fuel that can be used in any diesel engine without modification.

1,639 citations

Journal ArticleDOI
Abstract: The call for the use of biofuels which is being made by most governments following international energy policies is presently finding some resistance from car and components manufacturing companies, private users and local administrations. This opposition makes it more difficult to reach the targets of increased shares of use of biofuels in internal combustion engines. One of the reasons for this resistance is a certain lack of knowledge about the effect of biofuels on engine emissions. This paper collects and analyzes the body of work written mainly in scientific journals about diesel engine emissions when using biodiesel fuels as opposed to conventional diesel fuels. Since the basis for comparison is to maintain engine performance, the first section is dedicated to the effect of biodiesel fuel on engine power, fuel consumption and thermal efficiency. The highest consensus lies in an increase in fuel consumption in approximate proportion to the loss of heating value. In the subsequent sections, the engine emissions from biodiesel and diesel fuels are compared, paying special attention to the most concerning emissions: nitric oxides and particulate matter, the latter not only in mass and composition but also in size distributions. In this case the highest consensus was found in the sharp reduction in particulate emissions.

1,638 citations

Journal ArticleDOI
Abstract: Gasoline- and diesel-powered vehicles are known to contribute appreciable amounts of inhalable fine particulate matter to the atmosphere in urban areas. Internal combustion engines burning gasoline and diesel fuel contribute more than 21% of the primary fine particulate organic carbon emitted to the Los Angeles atmosphere. In the present study, particulate (d[sub p] [le] 2 [mu]m) exhaust emissions from six noncatalyst automobiles, seven catalyst-equipped automobiles, and two heavy-duty diesel trucks are examined by gas chromatography/mass spectrometry. The purposes of this study are as follows: (a) to search for conservative marker compounds suitable for tracing the presence of vehicular particulate exhaust emissions in the urban atmosphere, (b) to compile quantitative source profiles, and (c) to study the contributions of fine organic particulate vehicular exhaust to the Los Angeles atmosphere. More than 100 organic compounds are quantified, including n-alkanes, n-alkanoic acids, benzoic acids, benzaldehydes, PAH, oxy-PAH, steranes, pentacyclic triterpanes, azanaphthalenes, and others. Although fossil fuel markers such as steranes and pentacyclic triterpanes can be emitted from other sources, it can be shown that their ambient concentrations measured in the Los Angeles atmosphere are attributable mainly to vehicular exhaust emissions. 102 refs., 9 figs., 6 tabs.

1,279 citations

Journal ArticleDOI
Abstract: Vegetable oil fuels have not been acceptable because they were more expensive than petroleum fuels. With recent increases in petroleum prices and uncertainties concerning petroleum availability, there is renewed interest in vegetable oil fuels for Diesel engines. Dilution of oils with solvents and microemulsions of vegetable oils lowers the viscosity, but some engine performance problems still exist. The purpose of the transesterification process is to lower the viscosity of the oil. Pyrolysis produces more biogasoline than biodiesel fuel. Soap pyrolysis products of vegetable oils can be used as alternative Diesel engine fuel. Methyl and ethyl esters of vegetable oils have several outstanding advantages among other new renewable and clean engine fuel alternatives. The main factors affecting transesterification are the molar ratio of glycerides to alcohol, catalyst, reaction temperature and pressure, reaction time and the contents of free fatty acids and water in oils. The commonly accepted molar ratios of alcohol to glycerides are 6:1–30:1.

1,074 citations

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