Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Catalytic Surface Coatings for Household Ovens(Izmir Institute of Technology, 2016) İzer, Alaz; Şeker, Erol; Şeker, ErolThe emission of harmful volatile compounds, such as aldehydes, and also carbon monoxide could occur during cooking processes at home or industry due to the combustion and cracking of spilled vegetable oil on the walls of an oven. It is known that the by-products generated during cooking could affect human health and environment if they are properly vented or removed. To eliminate the health and environmental problems related to oven emission, self-cleaning catalytic materials coated walls for ovens seem to be viable alternative to the toxic and time consuming chemical cleaning solutions. In this project, a sol-gel method and also the dip coating technique was used to produce a catalytic material coated aluminum plates. Specifically, the calcination time and the temperature were studied to better understand the relationship between the textural/chemical properties of the catalyst coated metal plates and their catalytic activities. The studied calcination temperatures were 450°C, 500°C and 550°C whereas the calcination time were 10 min, 30 min and 60 min for each type of catalyst. Aluminum oxide supported nickel and also aluminum oxide - manganese oxide supported nickel catalysts were prepared as the catalyst that were used in coating. The catalytic activities of the catalyst coated plates were determined using canola oil as a function of reaction time which were 1h at 170°C and 200°C. The results have been shown that the most convenient calcination conditions for the canola oil combustion were 500°C for 30 minutes by using aluminum oxide – manganese oxide supported nickel catalyst.Master Thesis Development of Tungsten Loaded and Zirconia Incorporated Mesoporous Catalysts for Esterification of Palmitic Acid With Cetyl Alcohol(Izmir Institute of Technology, 2014) Mutlu, Vahide Nuran; Yılmaz, Selahattin; Yilmaz, SelahattinIn this study, it was pursued to develop acidic mesoporous catalysts for esterification of cetyl alcohol by palmitic acid. For this, Zr incorporated SBA-15 was prepared by hydrothermal synthesis. Zr-SBA-15 was used both as a catalyst support and as a catalyst itself. WO3 loading onto the Zr-SBA-15 was performed by incipient wetness impregnation. Additionally, WO3-ZrO2 catalyst was prepared by co-precipitation with two different contents of WO3 (15 wt% and 20 wt%). The reaction tests were carried out in mesitylene under reflux conditions. Zr was incorporated into SBA-15 successfully. The surface areas of Zr-SBA-15 and WO3/Zr-SBA-15 catalysts were significantly higher than that of WO3-ZrO2. Loading of WO3 decreased the surface area of Zr-SBA-15. The acidity of the WO3/Zr-SBA-15 with 15 wt% WO3 was higher than that of with 20 wt% WO3. Moreover, increasing the calcination temperature from 700 to 800 oC resulted in the increase of acidity. The activity of the catalysts differed. The only product obtained was cetyl palmitate. Under the test conditions it was found that the reaction rate was not limited by equilibrium. Zr-SBA-15 provided the highest conversion (64 %) which corresponded to cetyl palmitate yield of 63% among other mesoporous catalysts because of its high surface area (600.3 m2/g) and acidity (0.152 mmol NH3/g cat). This catalyst did not show leaching. WO3/Zr-SBA-15 based catalys tests showed that catalyst activity increased by increasing calcination temperature. This was atributed to better dispersion of W. The conversion of cetyl alcohol did not change much with more W loading.