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Journal ArticleDOI

Influence of fuel properties and composition on NOx emissions from biodiesel powered diesel engines: A review

01 Aug 2012-Renewable & Sustainable Energy Reviews (Pergamon)-Vol. 16, Iss: 6, pp 3702-3710
TL;DR: In this article, the effect of fuel properties and composition on NO x emissions from biodiesel fuelled engines is reviewed and some general conclusions concerning this problem are summarised and further researches are pointed out.
Abstract: Biodiesel has proved to be an environment friendly alternative fuel for diesel engine because it can alleviate regulated and unregulated exhaust emissions. However, most researchers have observed a significant increase in NO x emissions with biodiesel when compared to petrodiesel. The exact cause of this increase is still unclear; however, researchers believe that the fuel properties have been shown to effect the emissions of NO x . The present work reviews the effect of fuel properties and composition on NO x emissions from biodiesel fuelled engines. The paper is organised in three sections. The first section deals with the NO x formation mechanisms. In the following section, the reasons for increased NO x emissions of biodiesel fuel are discussed. After this, the influence of composition and fuel properties on NO x emissions from biodiesel fuelled engines has been reviewed. Finally, some general conclusions concerning this problem are summarised and further researches are pointed out.
Citations
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Journal ArticleDOI
TL;DR: A review of recent advances in polymeric materials from vegetable oils in terms of preparation, characterization, and properties can be found in this article, where nano-composites and fiber reinforced composites based on bio-polymers matrices are reviewed.

449 citations

Journal ArticleDOI
TL;DR: In this article, the authors have collected and analyzed the data on both advantages and disadvantages of biodiesel over conventional diesel, and the highest consensus is related to enhanced corrosion of automotive parts due to its compositional differences.
Abstract: Biodiesel, derived from the transesterification of vegetable oils or animal fats, is composed of saturated and unsaturated long-chain fatty acid alkyl esters. In spite of having some application problems, recently it is being considered as one of the most promising alternative fuels in internal combustion engine. From scientific literatures, this paper has collected and analyzed the data on both advantages and disadvantages of biodiesel over conventional diesel. Since the aim of this study is to evaluate the biodiesel feasibility in automobiles, the first section is dedicated to materials compatibility in biodiesel as compared to that in diesel. The highest consensus is related to enhanced corrosion of automotive parts due to its compositional differences. In the subsequent sections, data on performance, emission and engine durability have been analyzed and compared. In this case, the highest consensus is found in reducing emissions as well as in increasing moving parts sticking, injector coking and filter plugging. This paper has also summarized the factors of biodiesel in contributing these technical performances.

412 citations

Journal ArticleDOI
TL;DR: In this paper, the fundamental combustion and emissions properties of advanced biofuels are reviewed, and their impact on engine performance is discussed, in order to guide the selection of optimal conversion routes for obtaining desired fuel combustion properties.
Abstract: The fundamental combustion and emissions properties of advanced biofuels are reviewed, and their impact on engine performance is discussed, in order to guide the selection of optimal conversion routes for obtaining desired fuel combustion properties. Advanced biofuels from second- and third-generation feedstocks can result in significantly reduced life-cycle greenhouse-gas emissions, compared to traditional fossil fuels or first-generation biofuels from food-based feedstocks. These advanced biofuels include alcohols, biodiesel, or synthetic hydrocarbons obtained either from hydrotreatment of oxygenated biofuels or from Fischer–Tropsch synthesis. The engine performance and exhaust pollutant emissions of advanced biofuels are linked to their fundamental combustion properties, which can be modeled using combustion chemical-kinetic mechanisms and surrogate fuel blends. In general, first-generation or advanced biofuels perform well in existing combustion engines, either as blend additives with petro-fuels or as pure “drop-in” replacements. Generally, oxygenated biofuels produce lower intrinsic nitric-oxide and soot emissions than hydrocarbon fuels in fundamental experiments, but engine-test results can be complicated by multiple factors. In order to reduce engine emissions and improve fuel efficiency, several novel technologies, including engines and fuel cells, are being developed. The future fuel requirements for a selection of such novel power-generation technologies, along with their potential performance improvements over existing technologies, are discussed. The trend in the biofuels and transportation industries appears to be moving towards drop-in fuels that require little changes in vehicle or fueling infrastructure, but this comes at a cost of reduced life-cycle efficiencies for the overall alternative-fuel production and utilization system. In the future, fuel-flexible, high-efficiency, and ultra-low-emissions heat-engine and fuel-cell technologies promise to enable consumers to switch to the lowest-cost and cleanest fuel available in their market at any given time. This would also enable society as a whole to maximize its global level of transportation activity, while maintaining urban air quality, within an energy- and carbon-constrained world.

343 citations

Journal ArticleDOI
TL;DR: In this article, the authors discuss comparative physicochemical properties of ethanol and gasoline and discuss different fuel composition, engine parameter and engine modification effects on NOx formation as well as mathematical approach for NOx prediction using ethanol.
Abstract: The stricter worldwide emission legislation and growing demands for lower fuel consumption and anthropogenic CO2 emission require significant efforts to improve combustion efficiency while satisfying the emission quality demands. Ethanol fuel combined with gasoline provides a particularly promising and, at the same time, a challenging approach. Ethanol is widely used as an alternative fuel or an effective additive of gasoline due to the advantage of its high octane number and its self-sustaining concept, which can be supplied regardless of the fossil fuel. As a result, vast study has been carried out to study its effects on engine performance and emission. The first part of this article discusses prospect of fuel ethanol as a gasoline substitute. Then it discusses comparative physicochemical properties of ethanol and gasoline. The slight differences in properties between ethanol and gasoline fuels are enough to create considerable change to combustion system as well as behaviors of SI engines. These effects lead to several complex and interacting mechanisms, which make it difficult to identify the fundamentals of how ethanol affects NOx emission. After that, general NOx forming mechanisms are discussed to create a fundamental basis for further discussion. Finally, the article discusses different fuel composition, engine parameter and engine modification effects on NOx formation as well as mathematical approach for NOx prediction using ethanol.

327 citations


Cites background from "Influence of fuel properties and co..."

  • ...This mechanism of thermal NOx formation is believed to be the predominant contributor of total NOx [73]....

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  • ...Here, M is a general third body that is required to complete this reaction [73]....

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Journal ArticleDOI
TL;DR: In this paper, the impacts of biodiesel combustion on NOx emissions and their reduction approaches in diesel engines are reviewed and the results of reduction approaches of the NOx emission implies, exhaust gas recirculation (EGR) and retarded injection timing are effective as well as low cost techniques than others.
Abstract: Increasing energy demand and environment concerns have prompted an evolution of alternative fuel sources. As an alternative fuel source, biodiesel is attractive because it reduces engine emissions. However, biodiesel produces higher NOx emissions compared to ordinary diesel fuel. Previous researches have established many factors that cause biodiesel to produce elevated NOx emissions. This study reviews the impacts of biodiesel combustion on NOx emissions and their reduction approaches in diesel engines. The first part of this study recaps the NOx formation mechanisms for understanding the kinetics behind the NOx forming reactions. The second part describes the factors affecting on NOx emissions. This paper established that higher NOx emissions are produced for biodiesel combustion which influenced by several factors such as physicochemical properties and molecular structure of biodiesel, adiabatic flame temperature, ignition delay time, injection timing and engine load conditions etc. The final section discusses on the reduction of NOx emissions from biodiesel fuelled engines for both pre and post combustion techniques. The results of reduction approaches of the NOx emissions implies, exhaust gas recirculation (EGR) and retarded injection timing are effective as well as low cost techniques than others. Between these two techniques, EGR reduces the NOx emissions at 5–25% EGR rate adequately in biofuelled engine by controlling oxygen content and combustion peak temperature with slightly decreasing HC and CO emissions. However this technique shows few penalties on smoke and PM emissions as well as brake specific fuel consumption if not perfectly optimized.

321 citations


Cites background from "Influence of fuel properties and co..."

  • ...Residence time and the concentration of nitrogen and oxygen also have an influence on the production of thermal NO [28]....

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  • ...Many researchers have proposed many possible reasons for the increase of NOx emissions when biodiesel is used in diesel engine [10,23,28]....

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References
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Journal ArticleDOI
TL;DR: In this paper, structural features that influence the physical and fuel properties of a fatty ester molecule are chain length, degree of unsaturation, and branching of the chain, as well as the structural features of the fatty acid and the alcohol moieties.

2,145 citations


"Influence of fuel properties and co..." refers background in this paper

  • ...Short chain ranched esters have low CN, but they exhibit good cold flow roperties [110]....

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  • ...[110] Knothe G....

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  • ...oreover, Knothe [110] found non-linear relationship between he ignition delay period and the CN....

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Journal ArticleDOI
TL;DR: In this paper, the fatty acid (FA) profiles of 12 common biodiesel feedstocks were summarized, and it was shown that several fuel properties, including viscosity, specific gravity, cetane number, iodine value, and low temperature performance metrics are highly correlated with the average unsaturation of the FA profiles.
Abstract: Biodiesel is a renewable transportation fuel consisting of fatty acid methyl esters (FAME), generally produced by transesterification of vegetable oils and animal fats. In this review, the fatty acid (FA) profiles of 12 common biodiesel feedstocks were summarized. Considerable compositional variability exists across the range of feedstocks. For example, coconut, palm and tallow contain high amounts of saturated FA; while corn, rapeseed, safflower, soy, and sunflower are dominated by unsaturated FA. Much less information is available regarding the FA profiles of algal lipids that could serve as biodiesel feedstocks. However, some algal species contain considerably higher levels of poly-unsaturated FA than is typically found in vegetable oils. Differences in chemical and physical properties among biodiesel fuels can be explained largely by the fuels’ FA profiles. Two features that are especially influential are the size distribution and the degree of unsaturation within the FA structures. For the 12 biodiesel types reviewed here, it was shown that several fuel properties – including viscosity, specific gravity, cetane number, iodine value, and low temperature performance metrics – are highly correlated with the average unsaturation of the FAME profiles. Due to opposing effects of certain FAME structural features, it is not possible to define a single composition that is optimum with respect to all important fuel properties. However, to ensure satisfactory in-use performance with respect to low temperature operability and oxidative stability, biodiesel should contain relatively low concentrations of both long-chain saturated FAME and poly-unsaturated FAME.

1,527 citations


"Influence of fuel properties and co..." refers background in this paper

  • ...[113] showed that cetane values of the iodiesel increases with chain length and decreases with chain ranching and degree of unsaturation....

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Journal ArticleDOI
TL;DR: In this paper, the authors reviewed the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.
Abstract: The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum reserves. Petroleum based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain region of the world. Therefore, those countries not having these resources are facing a foreign exchange crisis, mainly due to the import of crude petroleum oil. Hence it is necessary to look for alternative fuels, which can be produced from materials available within the country. Although vegetative oils can be fuel for diesel engines, but their high viscosities, low volatilities and poor cold flow properties have led to the investigation of its various derivatives. Among the different possible sources, fatty acid methyl esters, known as Biodiesel fuel derived from triglycerides (vegetable oil and animal fates) by transesterification with methanol, present the promising alternative substitute to diesel fuels and have received the most attention now a day. The main advantages of using Biodiesel are its renewability, better quality exhaust gas emission, its biodegradability and the organic carbon present in it is photosynthetic in origin. It does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the green house effect. This paper reviews the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.

1,250 citations


"Influence of fuel properties and co..." refers methods in this paper

  • ...[74] Singh S, Dipti S....

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  • ...Fuel compositions of various feedstocks are analysed by Singh nd Dipti [74]....

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Journal ArticleDOI
TL;DR: In this article, the effect of biodiesel on engine power, economy, durability and emissions including regulated and non-regulated emissions, and the corresponding effect factors are surveyed and analyzed in detail.
Abstract: As a renewable, sustainable and alternative fuel for compression ignition engines, biodiesel instead of diesel has been increasingly fueled to study its effects on engine performances and emissions in the recent 10 years. But these studies have been rarely reviewed to favor understanding and popularization for biodiesel so far. In this work, reports about biodiesel engine performances and emissions, published by highly rated journals in scientific indexes, were cited preferentially since 2000 year. From these reports, the effect of biodiesel on engine power, economy, durability and emissions including regulated and non-regulated emissions, and the corresponding effect factors are surveyed and analyzed in detail. The use of biodiesel leads to the substantial reduction in PM, HC and CO emissions accompanying with the imperceptible power loss, the increase in fuel consumption and the increase in NOx emission on conventional diesel engines with no or fewer modification. And it favors to reduce carbon deposit and wear of the key engine parts. Therefore, the blends of biodiesel with small content in place of petroleum diesel can help in controlling air pollution and easing the pressure on scarce resources without significantly sacrificing engine power and economy. However, many further researches about optimization and modification on engine, low temperature performances of engine, new instrumentation and methodology for measurements, etc., should be performed when petroleum diesel is substituted completely by biodiesel.

1,181 citations


"Influence of fuel properties and co..." refers background in this paper

  • ...[1] Xue J, Tony E, Hansen A....

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  • ...Burning biodiesel in diesel engine produces a signifiant reduction in emissions of particulate matter, HC and CO but in ost cases also causes an increase in NOx emissions (about 10–23%) hen compared to diesel fuel [1–4]....

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Journal ArticleDOI
C.P. Fenimore1
01 Jan 1971
TL;DR: In this paper, the N2-O2-NO system has been shown to produce a faster, transient formation of nitric oxide in the primary reaction zone, and the transient formation did not occur in hydrogen or carbon monoxide flames.
Abstract: The formation was followed by probing flames of ethylene, methane, or propane with N2-O2 mixtures. The known kinetic laws of the well-understood N2-O2-NO system (limited by the rate of the reaction O+N2→N+NO) described the growth of nitric oxide in the post-flame gas, after hydrocarbons were consumed, but could not describe a faster, transient formation of nitric oxide in the primary reaction zone. The transient formation did not occur in hydrogen or carbon monoxide flames, and therefore, may involve an attack of carbon or hydrocarbon radicals on nitrogen molecules (e.g., CH+N2→HCN+N). At atmospheric pressure, the transient formation gave its greatest yield in flames containing 1.3 to 1.4 times the stoichiometric amount of fuel. Its yield increased somewhat with pressure, particularly in fuel-lean flames, so that at 3 atmos pressure the nitric oxide formed quickly in the primary reaction zone was about the same in flames of 0.8 as of 1.4 mixture strength. The transient formation possessed a relatively weak temperature dependence. Extrapolating the measurements, one can suggest that the new mechanism may contribute significantly to the emission of nitrogen oxides from a gas turbine, but the major contribution occurs by the known mechanism of the N2-O2 system.

790 citations


"Influence of fuel properties and co..." refers background in this paper

  • ...According to prompt or Fenimore mechanism [11], formation of free radicals in the flame front of hydrocarbon flames leads to rapid production of NO....

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  • ...[11] Fenimore C....

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