| Summary: | 碩士 === 國立宜蘭大學 === 環境工程學系碩士班 === 98 === Perfluorinated compounds (PFCs) has been invented since 1930. PFCs are widely used in many industries, such as the aluminum industry, electronic industry and semiconductor industry. However, they can increase the size of ozone layer hole, average surface temperature, sea-level rise and other serious disaster since molecular bonds between F and C, N, S have strong capacities on infrared rays absorption. In this study, mesoporous MCM-41 was adopted to be support of catalyst due to its easy preparation, high thermal stability and high surface area (> 1000 m2/g). CuO (Tenorite) and Fe2O3 (Haematitum) was coated over MCM-41 to make Cu-MCM-41 (0.5, 2.0, 5.0 wt%) and Fe-MCM-41 (0.5, 2.0, 5.0 wt%) catalysts to enhance the CF4 degardation activity.
CuO and Fe2O3 coated on MCM-41 can be identified with large angle XRPD patterns. The patterns of N2 adsorption/desorption isotherm of mesoporous materials is Type IV. In addition, the BET surface areas is between 1076 ~ 1248 m2/g. From TGA analysis, the results showed that total weight loss of mesoporous materials is ranged from 6.4 to 11.9%. Furthermore, the MCM-41 TEM images showed highly ordered pore arrangement and got the pore size of about 2.5 nm. In contrast, the pore arrangement direction of Cu-MCM-41 and Fe-MCM-41 is not consistent since the metal is doped into the pore.
The results also showed that CF4 degradation efficiency is only 6.1% at 1073K without catalyst. After the reactor is filled with MCM-41, Cu-MCM-41 and Fe-MCM-41 catalyst, degradation of efficiency is tended to be increased slightly. The best performance for controlling CF4 is to use 5wt% Cu-MCM-41 catalyst. The degradation efficiency is ranged from 12.5% to 19.7% when the temperature is increased from the 823K to 1073K. The degradation efficiency is ranged from 17.2% to 22.5% when the space velocity decreased from the 850 hr-1 to 210 hr-1. In addition, the efficiency decreases and inlet concentration increases.
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