Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Catalytic Pyrolysis of Virgin and Waste Polyolefins(01. Izmir Institute of Technology, 2023) Çalık, Fatma Defne; Yıldız, Günay; Şeker, ErolThe fact that increasing plastic production and the mismanaged waste released to the environment put the ecosystem at risk. One of the most promising recycling methods developed within this framework has been pyrolysis. In this thesis, a model feedstock mi (No: 119N302). Thermal (batch and continuous) and catalytic pyrolysis (in-situ and ex-situ) techniques were applied to the polyolefins. Silica-alumina-based solid acid catalysts were produced with the simple sol-gel method to compete with commercial ZSM-5 (30) and ZSM-5 (50). Catalyst-to-plastic ratios between 1/100 and 1/1000 were used for in-situ, and 200 h-1 and 500 h-1 WHSVs were used for ex-situ mode. 57 wt.% pyrolysis oil was produced from the thermal pyrolysis of the virgin PO mixture in the batch system. In the ex-situ catalytic pyrolysis experiments by 500 h-1 WHSV and by ZSM-5, silica-alumina, and ZSM-5 supported silica-alumina, 36 wt.%, 56.6% wt.% and 45.2 wt.% liquid, and by 200 h-1 WHSV, 29.9 wt.%, 54.1 wt.%, and 57.9 wt.% pyrolysis oils were collected, respectively. The most successful test in terms of product composition was ES2 with 82.9% gasoline (8.8% BTEX), and 16.7% diesel-range hydrocarbons. The motivation was investigating whether it was suitable to produce liquid hydrocarbons, in the range of C5-C20, as a feedstock in the petrochemical industry. As a result, it has been proven that energy recovery was possible and sustainable by plastics recycling instead of using fossil fuels.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 Experimental Investigation and Computational Fluid Dynamics (cfd) Analysis of Geothermal Sourced Hot Air Drying(Izmir Institute of Technology, 2022) Keleş, Nazlı; Gökçen Akkurt, Gülden; Helvacı, Hüseyin UtkuDrying is one of the oldest methods used to increase the product's shelf life and reduce transportation costs, consisting of heat and mass transfer between the product and the surrounding environment. One of the most common drying methods is hot air drying. The most critical parameters in hot air drying processes are drying air temperature, air velocity and relative humidity. Renewable energy resources can be used as heat/electricity in drying processes. Geothermal energy resources are highly suitable for hot air drying with their temperature compatibility and reliability. The geothermal resources in Turkey have a high potential for hot air drying. This Thesis examines tomato slices' quality parameters at different drying air temperatures and velocities. A cabinet-type geothermal sourced hot air dryer is installed in the Yenikale Heat Center of the Balcova-Narlidere Geothermal District Heating System in Izmir-Turkiye. Drying experiments are carried out at 40-60-80°C air temperatures and 0.5-1.5 m/s air velocities to examine their effects on drying kinetics and quality of dried tomatoes, such as pH, color, and moisture. With the help of the data obtained, drying time, drying rate, moisture rate, and effective diffusion coefficients are determined, and dimensionless moisture rate is modeled using thin layer models. Also, energy and exergy analyses are made for each experiment. Finally, experimental and simulation results are compared by using CFD to perform experimental design. The simulations created by using CFD are obtained in a much shorter time and more accurately since all materials used for the experiment are idealized.Master Thesis Statistical Analysis of the Effect of Meteorological Parameters on Pm10(Izmir Institute of Technology, 2022) Birim, Necmiye Gülin; Gökçen Akkurt, Gülden; Turhan, CihanAir pollution is a serious threat where the pollutants in the air in solid, liquid and gaseous states reach levels that would harm the natural balance of the environment and the lives of vital organisms. Especially in industrialized cities, in addition to the effects of urbanization, physical environment characteristics may also play a role in the formation of environmental problems. Therefore, it is of high importance to understand the characteristics of the natural environment in the studies on air quality, in order for urban spaces to be livable areas. In this study, the correlations between PM10 pollutant data and certain meteorological parameters that were obtained from 3 stations in İzmir province were statistically evaluated. PM10 data was studied according to pre-pandemic, mid-pandemic and post-pandemic periods between 2017–2021. Meteorological data was gathered for a twelve-month period between February 2021 and January 2022 and its effect on PM10 data for the same period was analyzed. In the statistical analysis that was performed via Minitab software, hourly average data of PM10 was the dependent variable; temperature, relative humidity, and wind speed and direction were the independent variables. In the analysis that Pairwise Pearson Correlation Coefficient (r) was used, the most significant correlation was found to be between relative humidity and wind speed.Master Thesis Coupled Wake and Blockage Modelling for a Wind Farm(Izmir Institute of Technology, 2022) Çam, Janset Betül; Bingöl, FerhatOne of the significant reasons for the power loss in wind farms is the wake effect. Therefore, the wake effect is crucial for designing a wind farm. However, only wake modeling is not sufficient to explain power losses. Wake is the turbulent, complex, and relatively weak flow behind the wind turbine. The wake effect is not required for the front row turbines in wind farms, and the wake model cannot be applied. It is assumed that the wind farm directly encounters the free stream wind speed. However, the blockage effect, also known as the induction zone effect, is observed at the front of the wind turbines. Due to this effect, the wind farm encounters a lower wind speed than the free-stream wind speed. This situation reduces the accuracy of the Annual Energy Production (AEP) calculation in wind farms. The motivation of this study is to obtain an improved coupled wake and blockage model that converges to the accurate SCADA data of a wind farm more than the wakeonly or blockage-only models. This study applies seven wake and six blockage models to the wind farm. The similarities and differences between the coupled models and the wind farm SCADA data and their reasons are discussed.Master Thesis Energy Performance Analysis and Materials Characterization of Aerogel Insulation Blankets(Izmir Institute of Technology, 2022) Alan, Selena; Gökçen Akkurt, Gülden; Akkurt, Sedatİzmir Geothermal Energy Inc. is a geothermal district heating company in İzmirTurkey that circulates hot water throughout the district via a 450 km of piping system and with the help of valves, pipes, and heat exchangers. As the distance traveled by the hot water is excessively long, heat losses are common. Rock wool is used as thermal insulation material, but the performance degraded over time because of water leakage. Instead of rock wool, aerogel insulation blanket use is evaluated in this study. Rock wool and three different aerogel insulation blankets are comparatively studied to assess their structures and thermal performances in two ways: the first is the characterization of materials by various physical and chemical analysis methods in the IZTECH-Integrated Research Center. The second way is to assemble a test setup on-site and make thermal measurements on the test setup for each aerogel insulation material, rock wool, and bare pipe. Heat loss calculations were conducted by EES software. The results are compared based on each characterization and thermal performance calculation. The thermal conductivity values of the insulation materials were calculated. Nonwetting properties were also checked to understand their hygrothermal properties. Compared with bare pipe, with the 10 mm thickness, rock wool decreases heat loss by 48-52%, and with the 10 mm thickness, the aerogel insulation blankets reduce heat loss by 57-61%. Finally, while aerogel insulation blankets have a better performance, they are more expensive than rock wool.