固態硼氫化鈉控制釋放產氫之模式建立與設計

Modeling and design of solid NaBH4 controlled release systems for hydrogen generation

鄭仰軒(Yang-Hsuan Cheng)

指導教授 ： 陳逸航

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2014年)

https://doi.org/10.6846/TKU.2014.00758

摘要

本研究利用Nylon 6,6 多孔性薄膜控制固態硼氫化鈉溶解釋放速率，使系統重量降低。以一次放氫為目標值，提供穩定氫源供給燃料電池發電，做為電子產品備用電源。透過多孔奈龍(Nylon 6,6)高分子薄膜，將液態水透過高分子之孔洞導入固態硼氫化鈉錠進行溶解，溶解後之硼氫化鈉溶液藉由濃度差擴散至外部溶液，經由系統設計與操作，可改變硼氫化鈉控制釋放速率。首先針對本系統建立質能平衡之數學模式，並與實驗結果進行印証比對模式之準確度。透過靈敏度分析，找出影響硼氫化鈉釋放量之設計與操作之主要變數各為：1. 薄膜厚度、薄膜尺寸，2. 操作溫度、外部水量。由模擬結果顯示，影響硼氫化鈉釋放速率之變數為薄膜厚度與薄膜面積，影響硼氫化鈉釋放之拖尾現象主要為內部水量。在實際應用上可透過改變操作溫度與溶液pH值來降低內部水量，以釋放拖尾之現象。最後，將鈷硼，釕觸媒置於外部溶液進行硼氫化鈉水解產氫之確認。

關鍵字

固態硼氫化鈉 ； 薄膜 ； 控制釋放 ； 設計 ； 氫氣

並列摘要

The objective of this work is to lighten the system weight by using Nylon 6,6 porous membranes to control release of solid NaBH4 tablets. This device provided stable hydrogen flowrate for PEMFC 3C product back-up power. Water permeated Nylon 6,6 porous membranes to dissolve solid NaBH4. The dissolved NaBH4 solution with a saturated concentration back-diffused through the porous membrane by concentration difference. In order to control the NaBH4 diffusion flux, mathematical models were built to describe the solid NaBH4 controlled release systems. The experiment was set-up. The external NaBH4 concentration was measured by iodine titration method once every 30 mins. The simulation result fit with experiment result well. After sensitivity analysis was made, design and operating variables of NaBH4 controlled release systems are: The membrane thickness, membrane area, operating temperature and external solution volume. The simulation result shows the membrane thickness and membrane area dominated the NaBH4 flux. The NaBH4 flux tail was affected by the internal volume. In real applications, operating temperature and solution pH value can be used as a manipulated variable to adjust internal volume. Finally, Co-B and Ru catalysts were placed in the external volume to promote NaBH4 hydrolysis reaction for hydrogen generation.

並列關鍵字

Solid NaBH4 ； Membrane ； Controlled release ； Design ； Hydrogen

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