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Öğe Hayvansal iç yağlardan transesterifikasyon reaksiyonu ile biyodizel üretilmesi(Doğu Anadolu Bölgesi Araştırma ve Uygulama Merkezi, 2008-07-31) Altun, Şehmus; Öner, CengizHayvansal yağlar normal çevre sıcaklığında katı ve çok viskozdurlar. Yüksek viskozitelerinden dolayı dizel motorlarında kullanılmadan önce modifiye edilmeleri gerekmektedir. Hayvansal yağların dizel motorlarında kullanılabilirliliğini iyileştirmek için emülsiyon ve transesterifikasyon etkili iki yöntemdir. Bu çalışmada hayvansal iç yağlardan baz katalizörlü transesterifikasyon ile %99.7 saflıkta metil alkol ve katalizör olarak %98 saflıkta NaOH kullanılarak hayvansal iç yağı metil esteri (biyodizel) üretilmiştir. Hayvansal iç yağı, metil ester şekline dönüştükten sonra viskozitesi önemli ölçüde azalmış ve oda sıcaklığında sıvı fazında bir yakıt elde edilmiştir. Biyodizelin belirlenen yakıt özellikleri ASTM standartlarında olup, viskozitesi ve yoğunluğu dizel yakıtına yakın, ısıl değeri ise %8 daha düşük çıkmıştır.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 Fuel properties of biodiesels produced from different feedstocks(Energy Education Science and Technolgy Part A, 2011) Altun, ŞehmusBio diesel is an oxygenated diesel fuel obtained from vegetable oils or animal fats via transesterification reaction. The fuel properties such as viscosity, density, cetane number and heating value are very important for determining the suitability of bio diesel as a diesel engine fuel. These fuel properties mainly depend on the feedstock which is used in the bio diesel production. In this study, the effect of bio diesels produced from different feed stocks such as inedible animal tallow, crude canola oil and canola oil blended with animal tallow on the fuel properties were experimentally investigated. Bio diesel fuels and their blends with petroluem diesel fuel were compared with petroleum diesel (petrodiesel). The results showed that the viscosity and density of all the methyl esters were higher than that of petrodiesel, while the heating values of the methyl esters was lower. Besides, the viscosity and the density of methyl esters are within the bio diesel standards, except for animal tallow methyl ester and it was slightly out of the specification EN 14214. Animal tallow bio diesel has the highest cetane number than those of other fuels include petrodiesel. It is concluded that bio diesels and their blends with petrodiesel have suitable fuel properties, especially cetane numbers, for diesel combustion process.Öğe The performance and emissions characteristics of a diesel engine fueled with biodiesel and diesel fuel(Kırıkkale Üniversitesi, 2010-01) Altun, Şehmus; Öner, Cengiz; Sugözü, İlkerThis paper presents the performance and emission characteristics of a diesel engine fueled with biodiesel and diesel fuel. The tests were performed in a four stroke, single cylinder, naturally aspirated, air-cooled and direct injection diesel engine at the different engine speed under full-load conditions. The results obtained with biodiesel were compared with the diesel fuel as reference fuel. The engine torque and power obtained in biodiesel were less, and the specific fuel consumption was found to be higher, which could be attributed to lower calorific value of biodiesel. CO emissions for biodiesel were lower than that of diesel fuel. However, it was observed that NOx emissions for biodiesel were higher than that of diesel fuel.Öğe Performance and emission characteristics of a diesel engine fueled with biodiesel obtained from a hybrid feedstock(Energy Education Science and Technology Part A: Energy Science and Research, 2011-04) Altun, ŞehmusVegetable oils and animal fats are widely investigated as a alternative fuel for diesel engines because of their high cetane number. However, animal fats are highly viscous and mostly in solid form at ambient temperature that they need modifications before using them in diesel engines. Pre-heated, blending, transesterification and emulsification are well known to improve usage of animal fats in diesel engines. In this study, biodiesel was produced from a hybrid feedstock (60% crude canola oil/40% inedible animal tallow) by transesterification and tested in a DI diesel engine for determining exhaust emissions and comparing those of biodiesel from pure animal tallow. Biodiesel fuels were tested as blends in diesel fuel (50% biodiesel and 50% diesel fuel). The experimental results show that, compared with animal tallow biodiesel blend, hybrid feedstock biodiesel blend has higher viscosity, density, brake specific fuel consumption, CO and NO x emissions and a lower cetane number, brake thermal efficiency.Öğe Biodiesel production from raw cottonseed oil and its performance in a diesel engine(Technology, 2011) Adin, Hamit; Yaşar, Fevzi; Öner, Cengiz; Altun, ŞehmusIn this experimental work, raw cottonseed oil was converted by KOH-catalyzed transesterification reaction with methyl alcohol to the cottonseed oil methyl ester (biodiesel) and then tested in a single cylinder, four strokes and direct injection diesel engine at the constant engine speed (2000 rpm) under different engine loads. The composition and the fuel-related properties of produced biodiesel were determined by using gas chromatography (GC) and related instruments. An increase in brake specific fuel consumption (BSFC) and decrease in brake thermal efficiency (BTE) for fuel blends were observed compared with diesel fuel. Compared with diesel fuel, exhaust emissions were found to be lower in carbon monoxide, hydrocarbon, nitrogen oxides and smoke with the use of fuel blends. It was concluded that cottonseed oil methyl esterdiesel fuel blends could be substituted for the diesel fuel without any modifications in diesel engines, with better environmental characteristics of fuel blends.Öğe Effects of isopropanol-butanol-ethanol (IBE) on combustion characteristics of a RCCI engine fueled by biodiesel fuel(Journals & Books, 2021-10) Altun, Şehmus; Okcu, Mutlu; Varol, Yasin; Fırat, MüjdatThe reactivity controlled compression ignition (RCCI) strategy using fuels with different reactivity’s has attracted attention due to its high thermal efficiency as well as very low NOx and PM emissions in comparison to conventional combustion. As previous studies have shown that the type and amount of low reactivity fuel have a significant contribution to the in-cylinder reactivity, thus RCCI combustion, in this study, Iso-Propanol-Butanol-Ethanol (IBE), which has comparable characteristics to n-butanol and ethanol, is employed as low reactivity fuel (LRF) in a RCCI engine fueled by petroleum based EN590 fuel and commercial biodiesel. The IBE mixture was in volumetric ratios of 3:6:1 as in the fermentation process of butanol, that is to say; 30% Iso-Propanol, 60% Butanol and 10% Ethanol. In each experimental condition, keeping the total energy of the fuel supplied to the engine in conventional combustion mode for each cycle as constant, the premixed ratio (Rp) in case RCCI combustion was applied as 0%, 15%, 30%, 45% and 60% (the amount of LRF in energy basis) over this energy amount. The effect of premixed ratio of IBE on combustion characteristics were investigated in a single-cylinder RCCI engine under different loads with using both petroleum diesel and biodiesel as high-reactivity fuels (HRF), respectively. According to experimental results, a higher in-cylinder pressure was measured by using diesel in both conventional and RCCI mode compared to the use of biodiesel. Considering the peak in-cylinder pressure and rate of heat release, the premixed ratio (Rp) of up to 45% was found as optimum for all loads while it was up to 30%Rp for the NOx emissions. In addition, the biodiesel-fueled RCCI engine produced the lowest smoke opacity in all loads and it gradually decreased by up to 97% with the application of the RCCI strategy. Furthermore, the results showed that a simultaneous reduction in NOx and smoke opacity could be obtained under 60% load and up to 30% Rp with a marginal increase in unburned HC emissions.Öğe Effect of biodiesel addition in a blend of isopropanol-butanol-ethanol and diesel on combustion and emissions of a CRDI engine(Taylor & Francis, 2021-05-21) Altun, Şehmus; İlçin, KutbettinThe increasing demand for energy and the fact that petroleum, which is the most used energy source, has a limited reserve, have led researchers to search for new and renewable energy sources. In this context, biofuels such as biodiesel and bio alcohols have been studied and used in internal combustion engines for a long time. However, with the developments in technology, the production and use of such alternative fuels in different engine technologies is still a subject of research. In this regard, isopropanol-butanol-ethanol (IBE) has received an increasing attention over standard alcohols and its potential as a substitute for other alcohol fuels in internal combustion engines has been researched recently. Therefore, the purpose of the experimental study is to investigate the effect of biodiesel addition at rates of 20% and 40% by volume in a blend of IBE (30% v/v) with petroleum-based diesel (70% v/v) on the combustion and emission characteristics of a single-cylinder common-rail direct injection engine at constant engine speed of 2400 rpm and 60% load conditions. Experimental results showed that all blended fuels presented a potential to reduce smoke opacity by 27% − 41%, CO emissions by 44% − 66% and unburnt HC emissions (up to 31.8%) but increase NOx emissions by 5% − 24.6% compared to diesel. However, adding biodiesel caused to a slight increase in smoke opacity and CO emissions while decrease in unburned HC and NOx emissions compared to the blend of IBE and diesel. Combustion analysis also showed that the use of blended fuels led to the increase of peak cylinder pressure (by 7%) and the significant improvement in the rate of heat release was observed, which further increased with the addition of biodiesel to blend of IBE and diesel. It was concluded that ternary blends was performed better than the blend of IBE and diesel while biodiesel addition was found to be beneficial in terms of reduction of unburnt HC and NOx emissions along with improved performance.Öğe Emissions from a diesel power generator fuelled with biodiesel and fossil diesel fuels(SAGE Journals, 2015-08-01) Altun, ŞehmusThe aim of this work was to compare the emission characteristics of a biodiesel derived from waste cooking sunflower oil and two fossil diesel fuels (ultra-low sulphur diesel and its type of containing gas-to-liquid). The tests were conducted on a direct-injection diesel engine-powered generator set, which is the type of generator applied in institutional facilities, under variable load and constant engine speed conditions. Experimental results showed that diesel containing gas-to-liquid and biodiesel reduced smoke opacity while NOx emissions were slightly higher for both fuels. An increase in fuel consumption was also observed for biodiesel compared with both fossil diesels. Unburned HC emissions were high for biodiesel, but overall level of CO emissions remained very low for all fuels testedÖğe Dizel motorlu bir jeneratörün egzoz emisyonları üzerinde biyoetanol, n-butanol ve biyodizelin etkisi(Dicle Üniversitesi, 2018-04-04) Altun, Şehmus; Seven, İsmailBu çalışmada biyoetanol, n-butanol ve biyodizel gibi alternatif yakıtların dizel motorlu bir jeneratörün performans ve egzoz emisyonları üzerindeki etkileri araştırılmıştır. Biyoetanol, n-butanol ve biyodizel sırasıyla konvansiyonel dizel yakıtına hacimsel olarak %10, %16 ve %30 oranlarında katılarak benzer oksijen içeriğine sahip alternatif dizel yakıtları elde edilmiştir. Bu karışım yakıtları ve konvansiyonel dizel yakıtı bir 4-zamanlı ve 4-silindirli doğal emişli dizel motorlu jeneratör setinde sabit devir (1500 dev/dak) ve farklı yük şartlarında test edilmiştir. Deneysel sonuçlar biyodizel katkılı yakıt karışımı kullanımında özgül yakıt tüketiminde yaklaşık %10 oranında bir artış olduğunu, efektif verimin ise önemli bir şekilde değişmediğini göstermiştir. Bununla beraber alkol katkılı karışım yakıtları kullanımında özgül yakıt tüketimi petrol dizeli kullanımına göre %8-10 arasında daha düşük olurken; efektif verim ise yaklaşık %5 oranında artmıştır. Alternatif yakıtların kullanımında ortalama NOx emisyonları dizel kullanımına göre düşmüş ve alkol katkılı yakıtların kullanımında bu düşüş daha fazla olmuştur. Yanmamış HC emisyonlarında ise tersi bir durum gözlemlenmiştir. Biyodizel karışımı ile HC emisyonları %20 oranında daha düşük olurken; alkol katkılı yakıtların kullanımı ile yaklaşık %15 oranında artmıştır. Duman emisyonları düşük ve orta yük kademelerinde alternatif yakıtlar ile ölçülmeyecek derecede düşük çıkmıştır
