Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Energy and exergy analysis of renewable energy utilization in cement production(01. Izmir Institute of Technology, 2025) Alaca, Pelin; Çağlar, Başar; Fard, Mousa MohammadpourGeleneksel çimento üretim yöntemlerine kıyasla daha yeşil enerji sistemleri alternatiflerini keşfetmek için çimento üretiminin enerji ve ekserji analizi çalışılmıştır. İki farklı yeşil enerji senaryosu dikkate alınmıştır. Temel senaryo geleneksel çimento üretimidir. İlk senaryoda atık rüzgar türbini kanatlarının pirolizi ve gaz türbini çimento fabrikasına entegre edilmiştir ve elektrik ihtiyacı gaz türbini tarafından karşılanmıştır. Aynı zamanda hammadde piroliz ünitesinin katı ürününden sağlanmıştır. Bu senaryo için sıcak akımları kullanmak üzere bir ön ısıtma sistemi düşünülmüştür. İkinci senaryoda, PEM elektrolizörü de çimento fabrikasına dahil edilmiştir. Burada kömürle değiştirilmek üzere PEM elektrolizöründen hidrojen üretilmiştir. Tüm senaryoların termodinamik modellemesi Engineering Equation Solver (EES) yazılımı aracılığıyla gerçekleştirilmiştir. Temel senaryonun enerji ve ekserji verimliliği sırasıyla % 61,60 ve % 20,21 olarak bulunmuştur. Termodinamik analiz dışında, özgül enerji tüketimi (SEC) ve CO2 emisyonları hesaplanmıştır. En düşük SEC, 1704 kJ/kg olan senaryo 1 ile elde edilmiştir. CO2 emisyonları, 0,219 kg CO2/kg çimento ile senaryo 2 için minimum olarak sonuçlanmıştır. Tüm bunlar göz önüne alınarak, daha yeşil ve daha az enerji tüketen bir sistem oluşturulmaya çalışılmıştır.Master Thesis Electrocatalytic isopropanol oxidation for direct organic fuel cells(01. Izmir Institute of Technology, 2024) Çetin, Yağmur; Çağlar, Başar; Şeker, ErolDünya üzerinde sürekli artan nüfus yoğunluğu ve buna eşlik eden enerji tüketim oranları nedeniyle, yenilenebilir enerji kaynaklarını bulma, bunları erişilebilir ve kullanıma hazır hale getirme ihtiyacı önemli konular gelmiştir. Son yıllarda, hidrojen taşıyıcıları ve yakıt hücresi sistemleri, geleneksel fosil yakıt türlerine bağlı enerji üretim sistemlerine iyi alternatifler olarak öne çıkmıştır. Bu çalışma için, hidrojen taşıyıcısı olarak izopropanol-aseton çifti seçilmiş ve reaksiyon kinetiği incelenmiştir. İzopropanolün elektrokimyasal oksidasyonu, yakıt hücresi uygulamaları ve enerji depolama cihazlarındaki önemi nedeniyle oldukça ilgi görmüştür. Bu tez içeriğinde, Pt/C, Cu/C, Pt-Cu(1:1)/C, Pt-Cu(3:1)/C ve Pt-Ru/C ticari katalizörleri kullanılarak izopropanolün elektrokimyasal oksidasyon davranışına odaklanılmıştır. Oksidasyon reaksiyonunun performansını iyileştirmeyi amaçlarken, her bir elektrokimyasal katalizörün aktivitesi, seçiciliği ve reaksiyon koşullarındaki kararlılığı farklı ortamların etkisi altında, alkali koşullarda incelenmiştir. Bu katalizörlerin elektrokimyasal performansı Döngülü Voltametri, Elektrokimyasal Empedans Spektroskopi ve Kronoamperometri analizleri ile değerlendirilmiştir. Sonuçlar, diğer Platin bazlı katalizörlere kıyasla daha yüksek katalitik aktivite ve daha düşük kinetik direnç gösteren Pt-Cu/C katalizörünün üstünlüğünü göstermektedir. Bu gelişmiş performans, Bakır'ın OH- türlerine olan güçlü afinitesine atfedilir ve bu da izopropanol oksidasyon hızını artırır ve genel elektrokimyasal aktiviteyi teşvik eder. Genel olarak, bu çalışma izopropanol elektrooksidasyonunun kinetiğine dair değerli bilgiler sağlayarak ve Pt-Cu alaşımının çeşitli elektrokimyasal sistemlerde verimli alkol oksidasyonu için umut verici bir katalizör olarak potansiyelini vurgular.Master Thesis Modelling and Controlling of Hybrid Energy Systems With Hydrogen Storage(01. Izmir Institute of Technology, 2023) Denizli, Osmancan; Çağlar, Başar; Altın, MüfitHybrid renewable energy systems are gaining more attention for the problems like Global Warming and high CO2 emissions. Another topic that increases its popularity is hydrogen. Because it is a very good alternative fuel. In this work, every component of a basic Hybrid Renewable Energy System (HRES) will be modeled and short-time simulations will be made for any transient response of individual components. MATLAB Simulink is used for every model and simulation. HRES includes a wind turbine, PV array, battery energy storage, and electrolyzer. The system is also grid-connected. Additionally, different control strategies are investigated, obtained, and created. Maximum Power Point Tracking (MPPT) algorithms for Wind Energy Conversion System (WECS) and PV array were conducted. A control algorithm that combines the battery and the PV array was made and necessary circuits were designed. An overall model for different sizes and operations is created. One-day-long simulations were made for 11 different cases. The user can alter the overall model for different turbines, PV modules, and battery sizes. The total amount of hydrogen produced, energy generation, and consumption were observed for every case.Master Thesis Modeling and Analysis of Heat Pump Integrated Pv-Wind Systems for a Commercial Greenhouse(01. Izmir Institute of Technology, 2023) Özcan, Zeynep; Çağlar, Başar; Bilir, LeventThis thesis focuses on modeling and simulating renewable energy (RE) systems that include photovoltaic (PV) panels, wind turbines (WT), and air source heat pumps (HP) for meeting the heating load of a commercial greenhouse (GH) in the agricultural zone in Dikili. Five different energy systems scenarios, namely (i) PV-HP, (ii) PV-WT-HP, (iii) WT-PV-HP, (iv) WT-HP, and (v) only HP were considered. For all scenarios the mismatch between the load and the generation was covered by grid. The second and third scenarios differ from each other based on the number of PVs and WTs. The design of the greenhouse was made with SketchUp and TRNSYS software based on dimensions of the greenhouse. According to the weather data and greenhouse parameters, solar radiation calculations were made, and the greenhouse system was modeled by MATLAB software. The annual heating and cooling demands of the designed greenhouse and electricity generation by PVs and WTs were calculated on an hourly basis. The heating and cooling loads were found to be 5,922,015 and 11,014,446 kWh/year, respectively. Since the maximum power output by RE for the reserved area is not sufficient to meet the cooling load, the cooling process was excluded. Economic and environmental analyzes were made. The first scenario including 5,271 PV panels and 20 HPs was found to be the best scenario. Net Present Value (NPV), Levelized Cost of Energy (LCOE) and CO2 savings of the related scenario were calculated as $547,440.40, 0.080146 $/kWh and 1,270.96 t.Master Thesis Techno-Economic Optimization of Pv-Wind Hybrid Systems(01. Izmir Institute of Technology, 2023) Demirdal, İlke; Çağlar, BaşarIn this study, the technoeconomic optimization of hybrid renewable energy systems were investigated for a small community with 50 households located in Izmir Institute of Technology (IZTECH) Campus, Izmir. The renewable-based power systems have received significant attentions recently due to the recent effort for the transition from fossil fuels to renewable energy, but their technical and economical feasibilities for different sectors and application areas and the related optimum system configurations haven’t been clearly addressed. To fill this research gap, PV-battery and wind turbine-battery system were analyzed for a small community from technical and economic point of views and the most economic configurations were explored for different level of grid-dependency by using the Loss of Power Supply Probability (LPSP) method. The annual electricity load profile was built in hourly basis based on the monthly total electricity consumption of each house and electricity consumption habits of residents. PV and wind turbine power outputs, the involvement of batteries were modelled in MATLAB/Simulink considering the meteorological data (IZTECH Meteorological Mast and NASA POWER), types of PV panel, wind turbine and battery. The mismatch between energy demand and supply was determined and different hybrid configurations were considered to cover this mismatch to different extents. The optimum number of PV panel, wind turbine and batteries were determined and the levelized cost of electricity were calculated for each scenario. The most economic configuration is the one consisting of 3 wind turbines and 7 batteries with 49.62% energy utilization from the grid.Master Thesis Thermo-Catalytic Pyrolysis of Unrecycled Plastic Waste in a Lab-Scale Experimental Set-Up: Determination of Optimal Operating Conditions(01. Izmir Institute of Technology, 2022) Ekici, Ecrin; Yıldız, Günay; Çağlar, Başar370 million tons of polymers are produced worldwide annually (with an annual growth of 4%), of which ca. 16% are produced in the European Union (EU). By 2030, it is estimated that over 600 million tons of plastics will be produced. Plastic waste is a problem and will be severe day by day for the environment. This problem can easily switch to advantage by a carbon-neutral process: pyrolysis. This study analyzed and compared reported literature data with the experimental findings obtained in a continuously operated bench-scale pyrolysis reactor. The optimal conditions of the feedstocks' N2 flow rate, feed intake, and mixing ratio for maximizing liquid production were estimated for pyrolysis by Taguchi’s orthogonal array design. Optimized process parameters were used for the pyrolysis of fresh and waste counterparts of HDPE, LDPE, PP, and a defined mixture of those (25:25:50 wt.%) at 450°C. The tail gases of mixed fresh and waste POs were also examined for energy autonomy of pyrolysis. Fresh plastics yielded more liquid compared to waste plastics. Blending polyethylenes with PP improved the conversion efficiency and favored the formation of gasoline-range hydrocarbons while limiting the wax formation. The total energy potential of produced NCGs, mainly composed of C3 hydrocarbons, was found to be sufficient; the energy demand for endothermic bond breaking during pyrolysis was met in a range of 139 to 464% for various plastic types tested.Master Thesis Hybrid Renewable Energy Systems Design for Green Campus-Iztech(01. Izmir Institute of Technology, 2022) Ramazan, Beste; Çağlar, Başar; Açıkkalp, EminThis study focuses on evaluating of standalone PV and Wind systems integrated with energy storage technologies to meet the electricity needs of the Izmir Institute of Technology campus in Izmir. University campuses with their high energy demand are one of the most important application areas for renewable energy systems and it’s critical to determine the types of renewable energy technologies, their size, and techno-economic feasibility for possible future implementation. Solar and wind energy were chosen as renewable energy sources based on the location and renewable energy potential of the IZTECH Campus. Two different energy storage systems are proposed to prevent any loss of power supply in standalone mode: (i) Lead-acid battery and (ii) Electrolyzer, hydrogen storage tank, and hydrogen-powered generator. Models were developed using the dynamic library-based structure of the TRNSYS program. The hourly electrical load was generated based on monthly data taken from the electricity supplier and the power output of PV modules was calculated based on the fixed tilt angle based on real meteorological data for the campus location. The electricity demand and generation were analyzed hourly for one calendar year. The number of PV modules was determined to meet the annual electricity demand of the campus while the capacity and number of energy storage modules were determined based on the maximum accumulative energy deficiency in a year. The round-trip efficiencies and the depth of discharge for the battery and the hydrogen storage efficiency for the hydrogen-based storage option were considered in the analysis. Parameters were calculated for both systems and simulation analyzes were evaluated. An economic cost analysis was performed for each system. In addition, suggestions are made for possible system improvements.Master Thesis Effect of Aging Electrolyte and Organic Coating Type on the Corrosion Mechanism of Tinplate(Izmir Institute of Technology, 2019) Yıldırım, Koray; Kızılkaya, Ali Can; Çağlar, BaşarMarket share of the can coating industry was 2 billion dollars in 2018 globally. A large portion of this market is focused on protecting valuable goods such as foods and cosmetics. Recent bans on the Bisphenol A(BPA) created a BPA-free coating demand due to the high portion of BPA based coatings in the industry such as epoxy. A conventional epoxy based (EP) can coating was compared with a new design of BPAfree polyester coating(PE). Atomic Force Microscopy(AFM), Scanning Electron Microscopy(SEM), Electron Dispersive Spectroscopy(EDX), Electrochemical Impedance Spectroscopy(EIS), Direct Current(DC) Polarization were used to investigate degradation. Industrial and model tinplate samples are compared with surface investigation methods. AFM results indicate the surface composition difference. To investigate bare tinplate corrosion, a mixture of acidic electrolyte was prepared and compared with other conventional aging electrolytes, containing mono acids. The electrolyte prepared from mixed acids was found to have the highest detinning abilities. Therefore, coated samples were aged with this mixed acid solution electrolyte. EIS results indicated that the type of electrolyte alters the corrosion mechanism, indicated by the observance of different time constants at different time scales. During immersion tests, EP based coatings showed better corrosion resistance as shown by higher impedance at low frequency, higher coating resistance and lower capacitance values. However, after sterilization, polyester coated samples showed better corrosion protective abilities (indicated by lower amount of corrosion products and higher impedance values) compared to the epoxy sample even though AFM measurements indicated that it had larger pore sizes after aging compared to epoxy sample. These results are attributed to the larger electrochemical area and higher diffusion properties of EP coatings, obtained after modelling of EIS data.