| Abstract: | 水電解產氫是目前製造氫氣常用之方法，而氫氣具有乾淨且對環境友善的特性，在未來相當具發展潛力，若能結合工業用的酸鹼廢液產氫，可減少廢棄物的增生，達到清潔生產的目的。
本實驗使用鎳為電極片，並應用硫酸及氫氧化鉀兩種溶液為電解液與Nafion質子交換膜隔離雙槽，進行電解水產氫之研究。並應用恆電位儀及氣體流量計記錄所得到的數據資料，探討不同濃度、單雙槽、電解液的不同對輸入電流、產氫量及能源效率的影響，並以增加電解液溫度、使用不同Nafion質子交換膜，及降低電位等參數，以研析其對產氫量及能源效率的提升效果。
實驗結果顯示，雙槽使用恆電位儀在5.5V的電位下，並搭配Nafion質子交換膜N212，能源效率最高可達65.9％，就單雙槽之比較，在相同濃度0.25M或0.5M時，雙槽不同電解液的能源效率皆優於單槽。若做溫度提升，溫度達40 ℃時，能源效率可提升至68.1％，50 ℃可提升80.1％，而產氫量皆有明顯的增加，如改用Nafion質子交換膜N211，能源效率皆有提升，且最高可提升到80.7％。如果降低電位時能源效率也皆有明顯提升的現象，在3.5V時能源效率更可提升到89.9％。;Water electrolysis hydrogen production is a common method for hydrogen production currently. Since hydrogen has a clean and environmentally friendly feature, it has considerable potential to be the energy resource in the future. If acid and alkaline waste solutions are used to produce hydrogen for industrial use, it can reduce the proliferation of industry waste to achieve the purpose of clean production.
In this study, using nickel sheets as electrodes, and applying two solutions of sulfuric acid and potassium hydroxide as the electrolytes contained in dual cells which are separated by a Nafion proton exchange membrane, water electrolysis hydrogen production is studied. By the use of potentiostat and gas flow meter to record the experimental data, the effects of working parameters, such as concentrations, single or dual-cell, and kind of electrolytes, on the resulted current, hydrogen production and energy efficiency are investigated. In addition, the influences of electrolyte temperature, thickness of Nafion and applied voltage upon the enhancement of hydrogen production and energy efficiency are also studied.
Results show that dual cell using potentiaostat at 5.5V with a Nafion N212 yields a energy efficiency up to 65.9%. At concentration of 0.25M and 0.5M, energy efficiencies in dual cell with different electrolytes are superior to that in single-cell. If the temperature is increased to 40 ℃, the energy efficiency could be increased to 68.1%, while it could even be raised to 80.1% at 50 ℃. The amount of hydrogen production are also increased significantly at the same time. If proton exchange membrane Nafion N211 was used instead of Nafion N212, the energy efficiency was improved, and even as high as 80.7%. Energy efficiency can also be improved when the applied voltage is low, e.g. , as potential at 3.5V, the energy efficiency is even enhanced to 89.9%. |
