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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 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 Fındık yağı biyodizelinin alternatif yakıt olarak bir dizel motorunda kullanılması(Doğu Anadolu Bölgesi Araştırma ve Uygulama Merkezi, 2008-03-30) Altun, Şehmus; Öner, Cengiz; Keven, ArzuBiyodizel, bitkisel ve hayvansal yağlar gibi yenilenebilir hammaddelerden üretilebilen alternatif dizel motor yakıtıdır. Bu çalışmada bir bitkisel yağ olan ham fındık yağından esterifikasyon ile fındık yağı etil esteri (biyodizel) elde edilmiş ve bu yakıtın dört zamanlı, tek silindirli, direk enjeksiyonlu ve hava soğutmalı bir dizel motorunda alternatif yakıt olarak kullanılabilirliği araştırılmıştır. Yapılan testlerde fındık yağı etil esterlerinin çok düşük olan viskozitesinden dolayı saf olarak kullanılamadığı görülmüştür. Bu nedenle fındık yağı etil esteri motorin ile hacimsel olarak %50 oranında karıştırılarak tekrar kullanılmıştır. Dizel yakıtı ile karşılaştırılma yapılırsa yakıt karışımı kullanıldığında motor performans değerlerinde iyileşme olduğu, ancak NOx emisyonunun da arttığı görülmüştür.
