Production of Hydrogen by Steam Reforming of Methanol over Copper-Based Catalysts Supportedon Praseodymium Oxide

• Main Authors: Min-Ke Chan, 詹旻珂
• Other Authors: 楊鴻銘
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/75568384891302546433

碩士 === 國立中興大學 === 化學工程學系所 === 98 === In this dissertation, the purpose of this study is to prepare copper based catalyst supported on praseodymium oxide and to apply it on steam reforming of methanol. The catalysts were tested by packed-bed reactor between 200℃ to 400℃. The parameters of catalyst preparation include the different deposition methods, ratios of promoter to support, different solutions, types of stabilizer, concentration of precursor and different second supports. Operating conditions in steam reforming of methanol included molar ratio of H2O/CH3OH, molar ratio of O2/CH3OH, weight hourly space velocity, and stability of catalysts. The results revealed that the catalyst prepared by precipitation and chemical reduction method is better than that prepared by co-precipitation method for this system. Doping of 10% small amounts of metal oxide promoters (Ce, Sm, Y, Zr) to the Cu-Pr2O3 catalyst enhanced the dispersion , activity of the catalyst and improved about 5% yield at 280°C. The catalyst added CeO2 has the best hydrogen yield of 91%. Y2O3-doped catalyst has the smallest volume fraction of carbon monoxide , 0.09V%. With the addition content of Y2O3 more than 16%, promoters would be too much and hide copper to decrease the activity of catalyst. Different catalyst stabilizers also affect the structure of catalyst significantly in the process of preparation of catalyst. CTMAB surfactant adsorbed on the catalyst surface will make the copper not reduced and inhibit the activity of copper. While the polyethylene glycol (PEG) change the structure and enhance the active catalysts effectively. Adding the alumina in the catalyst can improve the catalytic efficiency. In the stability test, the activity of Cu(25)/Pr2O3(75) catalyst remain 60% in the reaction of 20 hours, and the Cu(25)Y2O3(10)/Pr2O3(65) catalyst maintained at 80%. While the hydrogen yield of the catalyst added alumina almost had no decline in the reaction of 100 hours.