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Öğe Biodiesel production from inedible animal tallow and an experimental investigation of its use as alternative fuel in a direct injection diesel engine(Elsevier, 2009-02-15) Altun, Şehmus; Öner, CengizIn this study, a substitute fuel for diesel engines was produced from inedible animal tallow and its usability was investigated as pure biodiesel and its blends with petroleum diesel fuel in a diesel engine. Tallow methyl ester as biodiesel fuel was prepared by base-catalyzed transesterification of the fat with methanol in the presence of NaOH as catalyst. Fuel properties of methyl ester, diesel fuel and blends of them (5%, 20% and 50% by volume) were determined. Viscosity and density of fatty acid methyl ester have been found to meet ASTM D6751 and EN 14214 specifications. Viscosity and density of tallow methyl esters are found to be very close to that of diesel. The calorific value of biodiesel is found to be slightly lower than that of diesel. An experimental study was carried out in order to investigate of its usability as alternative fuel of tallow methyl ester in a direct injection diesel engine. It was observed that the addition of biodiesel to the diesel fuel decreases the effective efficiency of engine and increases the specific fuel consumption. This is due to the lower heating value of biodiesel compared to diesel fuel. However, the effective engine power was comparable by biodiesel compared with diesel fuel. Emissions of carbon monoxide (CO), oxides of nitrogen (NOx), sulphur dioxide (SO2) and smoke opacity were reduced around 15%, 38.5%, 72.7% and 56.8%, respectively, in case of tallow methyl esters (B100) compared to diesel fuel. Besides, the lowest CO, NOx emissions and the highest exhaust temperature were obtained for B20 among all other fuels. The reductions in exhaust emissions made tallow methyl esters and its blends, especially B20 a suitable alternative fuel for diesel and thus could help in controlling air pollution. Based on this study, animal tallow methyl esters and its blends with petroleum diesel fuel can be used a substitute for diesel in direct injection diesel engines without any engine modification.Öğe The comparison of engine performance and exhaust emission characteristics of sesame oil-diesel fuel mixture with diesel fuel in a direct injection diesel engine(Elsevier, 2008-01-09) Altun, Şehmus; Bulut, Hüsamettin; Öner, CengizThe use of vegetable oils as a fuel in diesel engines causes some problems due to their high viscosity compared with conventional diesel fuel. Various techniques and methods are used to solve the problems resulting from high viscosity. One of these techniques is fuel blending. In this study, a blend of 50% sesame oil and 50% diesel fuel was used as an alternative fuel in a direct injection diesel engine. Engine performance and exhaust emissions were investigated and compared with the ordinary diesel fuel in a diesel engine. The experimental results show that the engine power and torque of the mixture of sesame oil-diesel fuel are close to the values obtained from diesel fuel and the amounts of exhaust emissions are lower than those of diesel fuel. Hence, it is seen that blend of sesame oil and diesel fuel can be used as an alternative fuel successfully in a diesel engine without any modification and also it is an environmental friendly fuel in terms of emission parameters.Öğe Biodiesel properties of microalgae (Chlorella protothecoides) oil for use in diesel engines(Taylor & Francis, 2018-09-08) Yaşar, Fevzi; Altun, ŞehmusIn this study, biodiesel was produced from a microalgae oil, chlorella protothecoides, by typical alkali-catalyzed transesterification in conditions such as a 0.75 wt.% KOH of the oil as catalyst, 68°C and 80 min which was agreed as optimal conditions after investigating the effect of KOH concentration, reaction temperature and time at constant molar ratio of 6:1 on the conversion rate and fuel properties. Under these conditions, a 98.6% conversion rate of algae oil to its methyl ester was achieved with ester content higher than 96%. Furthermore, all physicochemical properties met the requirements of international biodiesel standards, EN 14214 and ASTM D 6751, with some remarkable ones such as high cetane number (57.3) and low CFPP (−10°C). The effect of microalgae biodiesel volume fraction in the fuel on the kinematic viscosity, CFPP, lubricity, density, and distillation temperature was also studied. A blending ratio of the algal-biodiesel up to 50% (v/v) was also found in agreement with the standards for biodiesel-diesel blends. From GC analysis, oleic and linoleic acids were found to be major fatty acids, and then the oxygen extended sooting index and adiabatic flame temperature were calculated using fatty acid distribution for evaluating the main diesel emissions such as soot and NO. As a result, the algae oil studied here was found to be an appropriate raw material for producing biodiesel and for using in Diesel Engines and its properties are within the typical ranges of conventional biodiesel fuels.Öğe Fuel properties of biodiesels produced from blends of canola oil and animal tallow(SILA SCIENCE, 2011-04) Adin, Hamit; Altun, Şehmus; Yaşar, FevziBiodiesel is an alternative diesel fuel that can be produced from renewable feedstocks such as vegetable oil or animal fats by transesterification with methanol for using in diesel engines. The viscosity and density of biodiesel fuels are important parameters due to being key fuel properties for injection and combustion process of diesel engines. These fuel properties mainly depend on the feedstock which is used in the biodiesel production. Also, lubricity is an important for diesel engine fuels due to the fuel injection systems are lubricated by the fuel itself. In this study, the blends containing 0, 25, 50, 75 and 100% of food-grade canola oil/inedible animal tallow in volume basis were prepared and converted into methyl esters by base-catalyzed transesterification. Effect of canola oil ration in the feedstock on the viscosity, density and lubricity were investigated. Lubricity was determined using the high-frequency reciprocating rig (HFRR) test. Experimental results showed that the kinematics viscosity of increased as animal tallow ratio increased in the feedstock, as animal tallow itself is more viscous than canola oil. Also, density did not change much when blended feedstocks were used. Besides, it was observed that lubricity of biodiesel fuels from blended feedstocks was slightly get worse compared with pure biodiesels.Öğe Biofuels derived from Turkish industry wastes - A study of performance and emissions in a diesel engine(Wiley-Blackwell, 2015-08-13) Altun, Şehmus; Rodríguez-Fernández, JoséRecently, research has focused on the biofuel production from local industrial wastes due to the risk of greenhouse emissions derived from land-use change (both directly and indirectly) of conventional feedstock and the social concern about the effect of conventional biofuel production on oil prices and its availability (the so-called food vs. fuel debate). Therefore, with the aim to evaluate the use of biofuels derived from wastes from traditional manufacturing industries in Turkey, biodiesel fuels from leather fat, obtained as a by-product in the leather industry, waste anchovy fish oil, derived from the fish-processing industry, and waste frying cottonseed oil achieved from food industry, have been tested in a three-cylinder DI diesel engine at a steady-state condition. In a previous work, the viability of these fuels was evaluated by analyzing measured and estimated properties and indicators for main diesel emissions, and recommendations were made on their alternative use to conventional biodiesels with the benefit of potentially lower life-cycle greenhouse emissions. The experimental results, which were compared with ULSD operation, demonstrated that the engine performance was not significantly affected, while a substantial change in emissions was observed with the use of biofuels. In general, the emission results reported here are in a similar range to those obtained with the use of conventional biodiesel fuels. Nonetheless, the exact magnitude of these changes depended upon the biodiesel origin. Lubricity of alternative biofuels was also tested, revealing an enormous capacity for protecting the fuel system from wear, in line with conventional biodiesel fuels.Öğe Effects of thermal barrier coating on the performance and combustion characteristics of a diesel engine fueled with biodiesel produced from waste frying cottonseed oil and ultra-low sulfur diesel(Taylor & Francis, 2016-09-01) Aydın, Selman; Sayın, Cenk; Altun, Şehmus; Aydın, HüseyinIn this study, the top surfaces of piston and valves of a four-strokes and direct-injection diesel engine have been coated—with no change in the compression ratio—with a 100 μm of NiCrAl lining layer via plasma spray method and this layer has later been coated with main coating material with a mixture of 88% of ZrO 2 , 4% of MgO and 8% of Al 2 O 3 (400 μm). Then, after the engine-coating process, ultra-low sulfur diesel (ULSD) as base fuels and its blend with used frying cottonseed oil derived biodiesel in proportion of 20%, volumetrically, have been tested in the coated engine and data of combustion and performance characteristics on full load and at different speeds have been noted. The results, which were compared with those obtained by uncoated-engine operation, showed that thermal efficiency increased, and engine noise reduced. Cylinder gas pressure values obtained from the diesel engine which has been coated with thermal barriers have been found to be somewhat higher than those of the uncoated-engine. Also, maximum pressure values measured in both engines and under the same experimental conditions through the use of test fuel have been obtained after TDC. Moreover, heat release rate and heat release have occurred earlier in the coated-engine. NOx emissions were increased while CO and HC emissions were remained almost the same with a little bit decrease.Öğe Biodiesel production from leather industry wastes as an alternative feedstock and its use in diesel engines(SAGE, 2013-11-01) Altun, Şehmus; Yaşar, FevziWaste leather fat is produced by the leather industry in fleshing processing and discarded as waste. These wastes can be used as a potential feedstock for biodiesel production due to their considerable fat content. In this work, raw fleshing oil which is a fat-originated waste of the leather industry was transesterified using methanol in the presence of an alkali catalyst to obtain biodiesel. The obtained biodiesel was then used in a four-stroke and direct injection diesel engine to evaluate the biodiesel behavior as an alternative diesel fuel, at a constant speed under variable load conditions. Blends [20 and 50% (v/v)] of biodiesel with diesel reference fuel were tested too. The emissions test results compared with diesel reference fuel showed that diesel engine fueled by biodiesel emitted significantly lower opacity and gaseous emissions than the same engine fueled by diesel reference fuel, and with very similar performance. The obtained data indicated that biodiesel from leather industry wastes is promising as an alternative fuel for diesel engines, and can be used to substitute diesel fuel in terms of performance and emission parameters without any engine modification.Öğe Properties and emission indicators of biodiesel fuels obtained from waste oils from the Turkish industry(Elsevier, 2014-03-14) Altun, Şehmus; Lapuerta, MagínThree waste oils from traditional manufacturing industries in Turkey, such as leather fat, obtained as a by-product in the leather industry, waste anchovy fish oil, derived from the fish-processing industry, and waste frying cottonseed oil from food industry, have been evaluated as alternative raw materials for biodiesel production, with potentially low life-cycle greenhouse emissions. Measured properties such as heating value, density, viscosity, flash point, acidity and cold flow properties, showed that the obtained biodiesel fuels fulfilled both the European and American quality standards and could be used to partially replace petroleum diesel in automotive engines. From gas chromatography analysis, detailed fatty acid profile was obtained, which permitted the application of group contribution methods for the estimation of thermodynamic properties (critical parameters, acentric factor) and thermochemical properties (enthalpies of vaporization and formation). This information was useful to calculate some indicators related to the most important diesel engine emissions, such as soot (main component of particulate matter) and nitric oxide emissions. Soot indicators reveal significant reduction potential with respect to fossil diesel fuels, and, among the studied biodiesel fuels, soot emissions would be lowest for the most saturated and shortest carbon-chain length biodiesel fuel. Adiabatic flame temperature, selected as the main nitric oxide emission indicator, shows small differences among the studied biofuels. Both the properties and emission indicators of the biodiesel fuels studied are within the typical ranges of other conventional biodiesel fuels.Öğe Effect of using bioethanol as fuel on start-up and warm-up exhaust emissions from a diesel power generator(Taylor & Francis, 2021-09-01) Altun, Şehmus; Adin, Mehmet Şükrü; Adin, Muhammed ŞakirThe present work investigates the effects of bioethanol as fuel additive on a diesel power generator’s exhaust emission (especially under transient conditions) characteristics, during the start-up followed by idling and warm-up periods, from no load to loaded cases up to 50% at ambient conditions. Experiments with diesel/bioethanol blends in 10% and 15% proportions (denoted as BE10 and BE15, respectively) were achieved in a diesel power generator following the practical operating conditions of the gen-sets. Regarding emissions, CO increased first when bioethanol is used during start-up at no load, then it starts to decrease by increasing bioethanol fraction in diesel and load applied. Unburnt HC emissions were also measured as highest for all fuels tested during start-up, while they were slightly higher for BE15 than others in the rest of the test. NOx was highest with petroleum diesel, while it was lowest with BE15 at start-up. Despite higher NOx was measured with BE10, those of petroleum diesel and BE15 were similar during warm-up together with applying load. Smoke opacity was lowest in BE15; however, BE10 was highest. By applying load, it increased and the highest NOx was measured with BE10, while the lowest was with BE15.Öğe Effect of the degree of unsaturation of biodiesel fuels on the exhaust emissions of a diesel power generator(Elsevier, 2013-09-25) Altun, ŞehmusIn this work, three biodiesel fuels with iodine numbers ranging from 59 to 185 were tested in a direct-injection diesel engine powered generator set at constant speed of 1500 rpm under variable load conditions to investigate the effect of the degree of unsaturation of biodiesel fuels, which are quantified by the iodine number, on the performance and exhaust emissions of a diesel engine. The increase in unsaturation involved a decrease in cetane number, and therefore, allowed for the maximization of the effect of the cetane number, while other properties, such as oxygen content, heating value, and viscosity, varied within a small range. Experimental results showed that biodiesel fuels resulted in lower emissions of nitrogen oxides, carbon monoxide, and smoke opacity, with some increase in emissions of unburned hydrocarbons. With their low energy content, neat biodiesel fuels resulted in an increase in fuel consumption compared to the conventional diesel fuel (ultra-low sulphur diesel). The degree of unsaturation of biodiesel fuels had effects on engine emissions via its effect on the cetane number and adiabatic flame temperature while engine performance was not significantly affected by the type of biodiesel fuel or its degree of unsaturation. The biodiesel having lowest iodine number had highest cetane number, and lowest density and adiabatic flame temperature, which was good to reduce NOx emissions, as it agreed with experimental results. Additionally, more unsaturated biodiesel fuels showed higher NOx emissions, smoke opacity, and lower HC emissions. It can be said that cetane number and adiabatic flame temperature are responsible for such results.
