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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 The fuel properties of methyl esters produced from canola oil- animal tallow blends by basecatalyzed transesterification(Kırıkkale Üniversitesi, 2010-06) Altun, Şehmus; Yaşar, Fevzi; Öner, CengizBiodiesel 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. 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 inedible animal tallow-canola oil blends on the viscosity and density of methyl esters were investigated. Experimental results showed that the kinematics viscosity of methyl esters increased as animal tallow ratio increased in the feedstock. Besides, it was observed that density did not change muchÖğe Exhaust emissions of methanol and ethanol-unleaded gasoline blends in a spark ignition engine(VINCA Institute of Nuclear Sciences, 2013) Altun, Şehmus; Öztop, Hakan Fehmi; Öner, Cengiz; Varol, YasinIn this study, the effect of unleaded gasoline and unleaded gasoline blended with 5% and 10% of ethanol or methanol on the performance and exhaust emissions of a spark-ignition engine were experimentally investigated. The engine tests were performed by varying the engine speed between 1000 and 4000 rpm with 500 rpm period at three-fourth throttle opening position. The results showed that brake specific fuel consumption increased while brake thermal efficiency, emissions of carbon monoxide and hydrocarbon decreased with methanol-unleaded gasoline and ethanol-unleaded gasoline blends. It was found that a 10% blend of ethanol or methanol with unleaded gasoline works well in the existing design of engine and parameters at which engines are operating.Öğe Exhaust emissions from a spark-ıgnition engine operating on Iso-propanol and unleaded gasoline blends(Technology, 2010) Altun, Şehmus; Öner, Cengiz; Fırat, MüjdatIn this study, the effect of blends of iso-propanol and unleaded gasoline on exhaust emissions of a sparkignition engine were experimentally investigated. Exhaust emission tests were conducted on a four-stroke, four cylinder and direct injection spark-ignition engine. The engine tests were performed at three-fourth throttle opening position at four various speeds in the range of 1000-4000 rpm with 1000 rpm period. The experimental results compared with unleaded gasoline showed that emissions of carbon monoxide (CO) and hydrocarbon (HC) decreased with iso-propanol-unleaded gasoline blends while carbon dioxide (CO2) emission increased.Öğe Biodiesel production from raw cottonseed oil and its characterization(Energy Education Science and Technolgy Part A, 2011-07) Altun, Şehmus; Yaşar, Fevzi; Öner, CengizIn this study, raw cottonseed oil of Turkish origin was transesterified using methyl alcohol and an alkali catalyst to obtain the cottonseed oil methyl ester. The obtained cottonseed oil methyl ester was analyzed by gas chromatography (GC) for determining the fatty acid composition. The fuel-related properties of cottonseed oil methyl ester, cold filter plugging point, cloud point, kinematic viscosity, density, cetane index, flash point, distillation, sulfur content and heating value were determined and compared with those of petroleum diesel fuel and international biodiesel standards. From gas chromatograph analysis, it was found that the cottonseed oil methyl ester has the more amount of total unsaturated FA, therefore, it showed better cold-flow properties than more saturated ones, as expected. Moreover, the fuel-related properties of cottonseed oil methyl ester were within the specified standardsÖğe An experimentally investigation of usability of a blend of tallow methyl ester and diesel fuel substitution of diesel fuel in diesel engines(Gazi Üniversitesi, 2010-07-06) Aydın, Hüseyin; Altun, Şehmus; Öner, Cengiz; Yücel, Halit LutfiBiodiesel fuels is one of the most attractive alternative fuels to reduce both emissions and petroleum based fuel consumption resulted from diesel engines. Therefore, the effects of biodiesel fuels on long-term engine operation and deposits in engine are considerably important, when biodiesel was evaluated as the alternative fuel for diesel engines. In this study, a 100 h engine test was performed on a single cylinder diesel engine using diesel fuel and tallow methyl ester as biodiesel fuel in order to compare the effects of the fuels on engine operation and deposits. The biodiesel was blended with 80 vol% diesel fuel and 20 vol % tallow methyl ester. Also, short-term engine performance and emissions were investigated and compared using both fuels. The test engine was disassembled before and after the experiment to determine the difference and clean carbon deposits. Experimental results were similar for both fuels in long-term engine tests, and indicated that the engine was satisfactorily operated for 100 hours with blend fuel. Deposits in engine at the end of the 100 h test were comparable in amount, but slightly different in color and adhesive, with the blend fuel when compared with those of diesel fuel. Besides, the blend fuel was comparable with the performance of diesel fuel and the exhaust emissions were lower than that of diesel fuel. It is concluded at the results of engine tests; the blend fuel can be a suitable alternative fuel for diesel engines to substitute diesel.Öğe Effect of a mixture of biodiesel diesel ethanol as fuel on diesel engine emissions(Electronic Journal of Vehicle Technologies, 2011) Altun, Şehmus; Yaşar, Fevzi; Öner, Cengiz; Fırat, MüjdatÖğe Improved combustion of asphaltite coals in a rotating head combustor with various air supply arrangements(ACS Publications, 2014-04-16) Altun, Şehmus; Öner, CengizWhen burned in conventional stokers, coals with high swelling properties such as asphaltites make coke blocks (coking). The plastic layer formed on them prevents air from diffusing into coal; hence, the air provided for swollen coal to burn becomes insufficient. This problem can partially be resolved by shaking the flame bed automatically or by mixing the burning coals manually in order to provide continuous air for the surface of the unburned coal. Therefore, in this study, a coal combustion system with the rotating head was manufactured for burning effectively Turkish coking coals characterized by high sulfur and ash content in agitation conditions with air supply arrangements. This type of coals known as asphaltite, abundantly found in southeastern Anatolia coal basin in Turkey, were burned in the rotating head combustor in order to investigate the effect of operating parameters, such as excess air ratio, coal particle size and feeding speed, air delivery type, addition of flange, bed slope, and rotation speed on the combustion efficiency and temperature distribution on the head. Experimental results showed that both the rotating of combustion chamber and additional air supply, which was blown out with pressure from the air delivery holes, reduced the negative impact of ash on the combustion efficiency, mainly due to the coal getting in touch with air better. It was possible to increase the peak combustion efficiency over 80% by both improving the air supply and agitation of coalbed preventing coking during combustion. As a result, this system could be highly recommended to burn the coals with high swelling properties like asphaltite at a high efficiency.Öğe Comparison of methanol, ethanol, or n-butanol blending with unleaded gasoline on exhaust emissions of an SI engine(Taylor & Francis, 2014-03-18) Altun, Şehmus; Varol, Yasin; Öner, Cengiz; Öztop, Hakan FehmiAir pollution is becoming a serious problem in many urban cities of the world and it can have a serious effect on both health and the environment. Although experimental studies have shown that alcohol fuels burn cleaner than unleaded gasoline and produce lesser emission, there is limited information regarding the comparison among the alcohol fuels as gasoline additive in spark-ignited engines. Therefore, a comparison has been performed in this experimental work on the exhaust emissions of a spark-ignited engine when operating on a blend of methanol, ethanol, or n-butanol with unleaded gasoline. Methanol, ethanol and n-butanol were added to unleaded gasoline by mass percent of 10% (denoted as M10, E10 and Bu10, respectively), and then tested in a four cylinder, four strokes spark-ignited engine. Although the experimental results show little differences in exhaust emissions between M10, E10, and Bu10, compared with Bu10, M10 and E10 have lower carbon monoxide emission and higher fuel consumption, hydrocarbon, and CO2 emission. Compared with unleaded gasoline, blended fuels containing different alcohols appear to have a lower carbon monoxide and hydrocarbon emissions and a higher fuel consumption rate and CO2 emissions.
