| Summary: | 碩士 === 聖約翰科技大學 === 自動化及機電整合研究所 === 97 === To supply hydrogen to fuel cell systems by methanol reforming method can solve the hydrogen storage problems. But the efficiency of reforming is affected by heat transfer and catalyst applied area. In order to improve the reforming efficiency, we made a reformer with micro-channel structure inside. This reformer is used to study how the methanol reforming rate, and hydrogen, carbon dioxide, and carbon monoxide concentrations are affected by reforming flow rate, carbon-steam ratio(C/S), and temperature. The micro-channel is formed on a thin metal plate by etching method. The CuO/ZnO mixed with Al2O3 powder is used as catalyst and spreads on the walls of channel. To prevent the gas clogged inside the evaporator, the methanol-water mixture is injected into a sophisticated-design evaporator by syringe pump. The reformed gases are collected into bags after condensation, and then analyzed by gas chromatography (GC). The results show that the methanol reforming rate is increasing when the temperature is higher. The reason is the reforming chemical reaction is endothermic. Higher temperature is benefit to chemical reaction also the reforming rate. The concentration of carbon monoxide is increasing when the mixture has small part of water which is high C/S. At the condition, 9c.c./h, 260℃, and C/S=0.443, the GC detected no carbon monoxide in the reforming gas. This criterion is very important to proton exchange membrane fuel cell system because of the catalyst poison. Increasing the inlet flow rate will decrease both the methanol reforming rate and concentration of hydrogen produced; however, the production rate of hydrogen is increased.
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