Dependence of biodiesel fuel properties on the structure of fatty acid alkyl esters

Effect of biodiesel fuels on diesel engine emissions

Introduction History of Vegetable Oil-Based Diesel Fuels The Basics of Diesel Engines and Diesel Fuels Biodiesel Production Basics of the Transesterification Reaction Alternate Feedstocks and Technologies for Biodiesel Production Catalysis in Biodiesel Processing Ion Exchange Resins in Biodiesel Processing Analytical Methods Analytical Methods for Biodiesel A Sensor for Discrimination of Fossil Diesel Fuel, Biodiesel, and Their Blends Fuel Properties Cetane Numbers-Heat of Combustion-Why Vegetable Oils and Their Derivatives Are Suitable as a Diesel Fuel Viscosity of Biodiesel Cold Weather Properties and Performance of Biodiesel Oxidative Stability of Biodiesel Biodiesel Lubricity and Effect of Biodiesel on Lubricants Biodiesel Fuels: Biodegradability, Biological and Chemical Oxygen Demand, and Toxicity Soybean Oil Composition for Biodiesel Exhaust Emissions Impacts of Biodiesel Fuel on Pollutant Emissions from Diesel Engines Ultrafine Particles from a Heavy Duty Diesel Engine Running on Rapeseed Oil Methyl Ester Current Status of the Biodiesel Industry Biodiesel in the United States Biodiesel in Germany and the European Union Biodiesel in South America Biodiesel in Asia Biodiesel in Japan Environmental Implications of Biodiesel (Life-Cycle Assessment) Potential Production of Biodiesel in the United States Other Uses of Biodiesel Other Alternative Diesel Fuels from Vegetable Oils ande Animal Fats Glycerol Technology Options for Biodiesel Industry Appendices: Technical Tables Biodiesel Standards Unit Conversions Internet Resources

The biodiesel handbook

As the fossil fuels are depleting day by day, there is a need to find out an alternative fuel to fulfill the energy demand of the world. Biodiesel is one of the best available resources that have come to the forefront recently. In this paper, a detailed review has been conducted to highlight different related aspects to biodiesel industry. These aspects include, biodiesel feedstocks, extraction and production methods, properties and qualities of biodiesel, problems and potential solutions of using vegetable oil, advantages and disadvantages of biodiesel, the economical viability and finally the future of biodiesel. The literature reviewed was selective and critical. Highly rated journals in scientific indexes were the preferred choice, although other non-indexed publications, such as Scientific Research and Essays or some internal reports from highly reputed organizations such as International Energy Agency (IEA), Energy Information Administration (EIA) and British Petroleum (BP) have also been cited. Based on the overview presented, it is clear that the search for beneficial biodiesel sources should focus on feedstocks that do not compete with food crops, do not lead to land-clearing and provide greenhouse-gas reductions. These feedstocks include non-edible oils such as Jatropha curcas and Calophyllum inophyllum , and more recently microalgae and genetically engineered plants such as poplar and switchgrass have emerged to be very promising feedstocks for biodiesel production. It has been found that feedstock alone represents more than 75% of the overall biodiesel production cost. Therefore, selecting the best feedstock is vital to ensure low production cost. It has also been found that the continuity in transesterification process is another choice to minimize the production cost. Biodiesel is currently not economically feasible, and more research and technological development are needed. Thus supporting policies are important to promote biodiesel research and make their prices competitive with other conventional sources of energy. Currently, biodiesel can be more effective if used as a complement to other energy sources.

A comprehensive review on biodiesel as an alternative energy resource and its characteristics

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.

Biodiesel production through the use of different sources and characterization of oils and their esters as the substitute of diesel: A review

Biodiesel is an alternative fuel consisting of the alkyl monoesters of fatty acids from vegetable oils or animal fats. Previous research has shown that biodiesel-fueled engines produce less carbon monoxide, unburned hydrocarbons, and particulate emissions compared to diesel fuel. One drawback of biodiesel is that it is more prone to oxidation than petroleum-based diesel fuel. In its advanced stages, this oxidation can cause the fuel to become acidic and to form insoluble gums and sediments that can plug fuel filters. The objective of this study was to evaluate the impact of oxidized biodiesel on engine performance and emissions. A John Deere 4276T turbocharged DI diesel engine was fueled with oxidized and unoxidized biodiesel and the performance and emissions were compared with No. 2 diesel fuel. The neat biodiesels, 20% blends, and the base fuel (No. 2 diesel) were tested at two different loads (100 and 20%) and three injection timings (3° advanced, standard; 3° retarded). The tests were performed at steady-state conditions at a single engine speed of 1400 rpm. The engine performance of the neat biodiesels and their blends was similar to that of No. 2 diesel fuel with the same thermal efficiency, but higher fuel consumption. Compared with unoxidized biodiesel, oxidized neat biodiesel produced 15 and 16% lower exhaust carbon monoxide and hydrocarbons, respectively. No statistically significant difference was found between the oxides of nitrogen and smoke emissions from oxidized and unoxidized biodiesel.

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=12949&context=rtd

The effect of biodiesel oxidation on engine performance and emissions

The alkyl monoesters of fatty acids derived from vegetable oils or animal fats, known as biodiesel, are attracting considerable interest as an alternative fuel for diesel engines. Biodiesel-fueled engines produce less carbon monoxide, unburned hydrocarbons, and particulate emissions than diesel-fueled engines. However, biodiesel has different chemical and physical properties than diesel fuel, including a larger bulk modulus and a higher cetane number. Some of these properties can be affected by oxidation of the fuel during storage. These changes can affect the timing of the combustion process and potentially cause increases in emissions of oxides of nitrogen. The objective of this study was to evaluate the effect of injection and combustion timing on biodiesel combustion and exhaust emissions. A John Deere diesel engine was fueled with two different biodiesel fuels, one of which had been deliberately oxidized, and with their 20% blends with No. 2 diesel fuel. The engine was operated at three different timings and two loads at a single engine speed of 1400 rpm. The engine performance of the biodiesel was similar to that of No. 2 diesel fuel with nearly the same thermal efficiency. The range of injection timings studied produced changes of 50% and 34% in the CO and HC emissions, respectively. A reduction in NO x emissions of 35% to 43% was observed for a 3° retarded injection timing compared with a 3° advanced injection timing. A common linear relationship was found between the start of injection and the NO x emissions for all the fuels studied. When compared at the same start of combustion, the neat biodiesel produced lower NO x emissions than the No. 2 diesel fuel.

The effect of timing and oxidation on emissions from biodiesel-fueled engines.

Biodiesel, an alternative diesel fuel consisting of the alkyl monoesters of fatty acids from vegetable oils and animal fats, can be used in existing diesel engines without modification. However, property changes associated with the differences in chemical structure between biodiesel and petroleumbased diesel fuel may change the engine's injection timing. These injection timing changes can change the exhaust emissions and performance from the optimized settings chosen by the engine manufacturer. This study presents the results of measurements of the speed of sound and the isentropic bulk modulus for methyl and ethyl esters of fatty acids from soybean oil and compares them with No. 1 and No. 2 diesel fuel. Data are presented at 21±1°C and for pressures from atmospheric to 34.74 MPa. The results indicate that the speed of sound and bulk modulus of the monoesters of soybean oil are higher than those for diesel fuel and these can cause changes in the fuel injection timing of diesel engines. Linear equations were used to fit the data as a function of pressure, and the correlation constants are given.

The Speed of Sound and Isentropic Bulk Modulus of Biodiesel at 21°C from Atmospheric Pressure to 35 MPa

Biodiesel is an alternative fuel for diesel engines that can be produced from renewable feedstocks such as vegetable oil and animal fats. These feedstocks are reacted with an alcohol to produce alkyl monoesters that can be used in conventional diesel engines with little or no modification. Biodiesel, especially if produced from highly unsaturated oils, oxidizes more rapidly than diesel fuel. This article reports the results of experiments to track the chemical and physical changes that occur in biodiesel as it oxidizes. These results show the impact of time, oxygen flow rate, temperature, metals, and feedstock type on the rate of oxidation. Blending with diesel fuel and the addition of antioxidants are explored also. The data indicate that without antioxidants, biodiesel will oxidize very quickly at temperatures typical of diesel engines. This oxidation results in increases in peroxide value, acid value, and viscosity. While the peroxide value generally reaches a plateau of about 350 meq/kg ester, the acid value and viscosity increase monotonically as oxidation proceeds.

Accelerated oxidation processes in biodiesel

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Abdul Monyem

Papers

The effect of biodiesel oxidation on engine performance and emissions

The effect of timing and oxidation on emissions from biodiesel-fueled engines.

The Speed of Sound and Isentropic Bulk Modulus of Biodiesel at 21°C from Atmospheric Pressure to 35 MPa

Accelerated oxidation processes in biodiesel

Determining the Influence of Contaminants on Biodiesel Properties