Summary: | 碩士 === 逢甲大學 === 化學工程學所 === 92 === Hydrogen energy is a relatively new type of energy. It is a source for fuel cells. How to produce and use hydrogen energy has become an important issue. Ethanol is a widely available renewable resource. In recent years, much attention has been focused on the study of ethanol steam reforming. This main objective of this research is to investigate the ethanol steam reforming in a palladium-silver alloy membrane reactor to produce hydrogen of high purity. A palladium-silver alloy membrane is used to separate hydrogen and the other products during the steam reforming process. The hydrogen produced can permeate through a palladium-silver alloy membrane and be collected on the other side of the membrane. The reactor used a porous stainless steel tube that was plated sequentially with palladium and silver film, with an overall thickness of 20μm, using the electroless plating technique. The reaction temperatures range from 350℃ to 450℃ and the pressures between 3atm and 10atm. An industrial catalyst MDC-3 is used for ethanol steam reforming reaction. A liquid water-ethanol mixture (volume ratio 3:1) is fed into the reactor with feed rate is 15cc/h (WHSV=5h-1). The result shows that the maximum yield for fluxes of hydrogen is 609.02 mol /m2-h and the recovery of hydrogen is 13.45% at T=450℃ and P=10atm. The optimal ethanol conversion (81.54%) is at T=450℃ and P=3atm. When a sweep gas is used, ethanol conversion and recovery of hydrogen increase. Under the same experiment condition, ethanol conversion and recovery of hydrogen in the steam reforming reaction are batter than those in the ethanol dehydrogenation reaction.
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