Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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Access Right: Open AccessSubject: search.filters.subject.Biodiesel fuels

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  • Master Thesis
    Spray Characteristics of Emulsified Biodiesel-Diesel Blends in a Constant Volume Combustion Chamber
    (01. Izmir Institute of Technology, 2020) Özkol, Ünver; Özkol, Ünver; Özkol, Ünver; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Over the last decades, various studies have been carried out by the researchers to find out an alternative fuel that can overcome emission problems caused by diesel fuel which affect the environment and human health significantly. Due to emulsified biodiesel-diesel blend (EBB) fuels are being a possible alternative fuel for diesel, in this study, it was aimed to investigate the macroscopic spray parameters such as spray penetration length and cone angle of different EBB fuels, namely B20W15 and B20W5, containing 15% and 5% water by volume, respectively. In order to examine the spray characteristics of B20W15 and B20W5, the experiments were carried out by means of constant volume combustion chamber and utilizing shadowgraph technique with a high-speed camera. Experiments were performed with 600 bar and 800 bar injection pressure while the ambient pressure was 0 bar, 5 bar and 10 bar, respectively. After experiments were fulfilled, the recorded images of test fuels were processed via ImageJ program. The results showed that stability of the emulsion can be obtained when HLB value was 8 and surfactant concentration was 5% by volume. It was understood that increment in water concentration in the emulsion caused deterioration in emulsion stability while it led higher viscosity, higher density, longer spray penetration lengths and narrower cone angles. It was observed that B20W5 resulted wider spray cone angles and shorter spray penetration lengths than B20W15 under 0,5 and 10 bar chamber pressure with injections pressures of 600 and 800 bar. Also, it was understood that both EBB lead longer spray penetration lengths and narrower spray cone angles compared to reference diesel while they lead vice versa compared to reference biodiesel. The reason of spray geometry difference between diesel and EBB fuels can be associated with the higher viscosity and density of EBB fuels compared to diesel. As a result, considering that B20W5 reduce the use of fossil fuels, and no significant difference compared to diesel in terms of spray geometry, it can be said that B20W5 may be a promising alternative fuel for the futur
  • Master Thesis
    Spectroscopic Determination of Vegetable Oiland Biodiesel in Petroleum Diesel Using Mulitivariate Calibration
    (Izmir Institute of Technology, 2008) Arıkan, Aysun; Özdemir, Durmuş; Özdemir, Durmuş; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    Due to the limited petroleum reserves and pollutant effect of petroleum fuels, the use of alternative fuels has became important in recent years. Diesel is one of the most used petroleum fuel, whose exhaust emissions composed of harmful particles, that pollutes the environment. In this sense, vegetable oils and their esters (biodiesel) are considered environmentally friendly fuels, which reduce hazardous impact of diesel emissions. However, using vegetable oils directly in diesel engines may cause some engine problems due to their high viscosity. The most commonly used way to reduce their viscosity is the converting into biodiesel. Because biodiesel production is expensive and time consuming, diesel may be illegally adulterated with vegetable oils before converting into biodiesel.Diesel may also adulterated with kerosene due to the large price differences. The main impact of this adulteration is increased emissions, which damage the environment. On the other hand, the addition of kerosene may also damage the engine. Because of these reasons, it is important to determine these adulterants illegally present in petroleum diesel. In this study, we have determined the adulteration of diesel with sunflower, canola oil, used frying oil, kerosene, and biodiesel by different molecular spectroscopic techniques combined to genetic inverse least squares (GILS). The results showed that the GILS method is suitable in the fast determination of diesel adulteration with vegetable oils, used frying oil, kerosene, and biodiesel when combined to NIR, FTIR-ATR, and molecular spectroscopic techniques.
  • Master Thesis
    Biodiesel Production From Safflower Using Heterogeneous Cao Based Catalysts
    (Izmir Institute of Technology, 2012) Yalman, Emir; Şeker, Erol; Şeker, Erol; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    In this study, the activities of heterogeneous mixed oxide catalyst; calcium oxide on alumina was investigated in the transesterification of canola and safflower vegetable oils to produce biodiesel, i.e. methyl esters. The primary goal of this study is to understand the effect of calcination temperature and calcium oxide (CaO) loading on the conversion activity of calcium oxide on alumina in the transesterification of canola and safflower vegetable oils. The mixed oxide catalyst was prepared by a modified single step sol-gel method. Calcium oxide was chosen because of its well known basic property. This study shows that calcium oxide on alumina catalysts having high CaO dispersion, calcined at high temperature, gave high biodiesel yields even under the reaction conditions, such as low reaction temperature, 50 °C, 9 of methanol/Oil molar ratio, 6 wt. % of catalyst/oil, and also short biodiesel reaction time, such as 4 – 10 minutes in the transesterification of safflower and canola oils. Also, it was observed that 70% CaO/Al2O3 catalyst when calcined at 700 °C was the most active catalyst among all the catalysts prepared in this study. Moreover, the reusability of CaO/Al2O3 demonstrated that ~20 – 250 ppm of Ca was lost during the reaction and the amount of Ca cation leaching depended on the reaction time, CaO loading and the calcination temperature. Also, it was found that Ca cation loss occurred during the reaction did not hinder the activity of the catalysts, which was found by the reusing the catalysts for couple times. Besides, when the biodiesel yield was higher than 70%, the system was influenced by external mass transfer limitation.