Meslek Yüksekokulu, Kimya ve Kimyasal İşleme Teknolojileri Bölümü, Makale Koleksiyonu
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Öğe The effect of microalgae biodiesel on combustion, performance, and emission characteristics of a diesel power generator(VINCA Institute of Nuclear Sciences, 2018) Yaşar, Fevzi; Altun, ŞehmusMicroalgae oil is expected to be a relevant source of biofuel in the future as it is more favorable to confront the problems of food shortages and greenhouse emission challenges raised by conventional biofuels. Therefore, in this study, a most common kind of microalgae that have a great potential, Chlorella protothecoides, was evaluated as fuel in terms of its combustion and emission characteristics in a Diesel engine-powered generator set at constant engine speed of 1500 rpm under various loads after converting its oil to biodiesel by typical base-catalyzed transesterification process. A biodiesel/diesel blend at the rate of 20% by volume was tested too. According to results obtained, using biodiesel resulted in an increase in fuel consumption, in a slight reduction of efficiency, and in sharp reductions in both unburned hydrocarbon emissions and smoke opacity especially at light loads, despite increasing NOx emissions were observed when compared with conventional petroleum diesel. In addition, premixed combustion ratio was higher for biodiesel than for diesel while total combustion duration took shorter for biodiesel especially at higher loads. The overall results of the study reveals that the combustion parameters of the biodiesel studied here are within the typical ranges of conventional biodiesel fuels.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 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 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 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 Batman şehir merkezinde hava kirliliği ve kontrolü(Batman Üniversitesi, 2017) Adin, Hamit; Yaşar, Fevzi; Altun, Şehmus; İşcan, BahattinBu çalışmada yapılan analizler, geçmiş yılların verileri ve en önemli atmosferik hava kirliliği bileşenlerinin ölçüm değerleri kullanılarak Batman şehir merkezindeki hava kirliliği kalite indekslerine göre araştırılmıştır. Batman şehir merkezide, hava kirliliği oluşturan temel bileşenlerden olan kükürtdioksit(SO2) ve partikül maddeler (PM) 2006-2011 yılları için incelenmiştir. Ölçülen değerler, Hava Kalitesi Kontrol Yönetmeliği (HKKY) ve Avrupa Birliğinin (AB) belirlediği sınır değerlere göre kıyaslanmıştır. Buna göre, Batman şehir merkezindeki hava kirliliği sınır değerleri HKKY değerlerinin altında kalmış fakat AB’nin belirlediği sınır değerlerin üstünde kalmıştır. Sonuç olarak, Batman şehir merkezinde düzenli hava kalitesi ölçümleri yapılmamakta olup, yerel bir çevre komitesinin oluşturulması, hava kirliliğinin önlenmesinde gerekli tedbirlerin alınması gerekmektedir. Alınması gereken tedbirler ayrıca sıralanmıştır.
