Photodegradation of aqueous isopropanol and simultaneouswater splitting to separate produced hydrogen

• Main Authors: Yu-Tang Lin, 林玉堂
• Other Authors: Chi-Sheng Wu
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/ab8hqq

碩士 === 國立臺灣大學 === 化學工程學研究所 === 107 === This research focuses on the photodegradation of aqueous isopropanol and simultaneous separation of produced hydrogen. First, isopropanol widely exists in wafer cleaning processes so it is one of the most extensive organic wastewater in semiconductor and photoelectric industries. In order to remediate isopropanol wastewater problem, photodegradation is one of the promising technology and meet the goal of water reuse. Secondly, hydrogen is green energy so it would not produce any pollutant but water after combustion. Moreover, hydrogen evolution by photocatalysis is a clean and low-energy consuming technique. This research takes advantage of a twin reactor to photodegrade aqueous isopropanol and separate produced hydrogen simultaneously. Compared to a single reactor, the twin reactor can prevent sking effect of photocatalyst and inhibit reverse reaction of water splitting. In experiment, WO3 is selected for isopropanol photodegradation catalyst, and Ru/SrTiO3:Rh is selected for hydrogen evolution catalyst which is synthesized by solid-state fusion at high temperature, and Ru is loaded by photodeposition. A Nafion membrane allows counter diffusion of Fe2+ and Fe3+ as electron mediators under the acid condition in the twin reactor. In order to simulate sunlight, the irradiation used a 300 W Xe lamp with AM1.5 filter as light source. Dual function reaction is conducted in the twin reactor. The result shows that 38% of isopropanol is degraded during 5-hrs reaction (initial concentration 20 ppm). Compared with a single reactor, the twin reactor can increase more isopropanol degradation up to 125%. Also, the amount of 143.08 µmol/g H2 is generated by the twin reactor, which is 37% more in hydrogen evolution compared to a single reactor. Furthermore, due to the separation of the hydrogen evolution side and the degradation side, 95% of pure hydrogen is achieved in hydrogen evolution side, thus decrease cost of afterward purification. Compared to pure water splitting, hydrogen evolution increases up to 15% by additional isopropanol (initial concentrations ranged 0 ~ 20 ppm). In summary, this study demonstrates that adding isopropanol wastewater can indeed increase H¬2 production in the twin reactor.