硼氫化合物放氫行為研究

Research of Hydrogen Discharge Performance for Borane

蔡幸芬(Shing-Fen Tsai) ； 許雅意(Ya-Yi Hsu)

《燃燒季刊》 74期 (2011/08) Pp. 13-22

https://doi.org/10.30041/CQ.201108.0002

摘要

氫能源開發基於氫氣具有低污染、潔淨的優勢，且具有使用在汽車燃料上之潛力，為減少溫室氣體排放不可或缺的一環。化學儲氫材料中之硼氫化合物具有高儲氫量，經由適當的活化機制轉換為氫氣釋出，透過燃料電池即可發電。本研究中選用硼氫化鈉、硼氫化鋰、硼氫化鉀、硼氫化鈣及硼氫化鎂等五項化學氫化物材料，乃是基於硼氫化合物中之硼氫化鋰、硼氫化鉀、硼氫化鈣及硼氫化鎂等，分別具有18.4wt%、7.4 wt%、12wt%及15wt%之高儲氫量。研究實驗中針對五項硼氫化合物，經由不同燃料量及不同水溶液濃度之參數調變，進行水解放氫反應試驗，並分析其氫氣釋放趨勢進而探討其行為表現。實驗結果顯示，於10g燃料量及2 wt%水溶液濃度下，經水解反應呈現之瞬間流量反應趨勢，說明硼氫化鈉之放氫反應行為屬最快速者，且硼氫化鈉、硼氫化鋰、硼氫化鉀三者之反應趨勢較相近，而硼氫化鈣及硼氫化鎂則呈現平緩相似之放氫趨勢。另一方面，對於累積放氫量而言，硼氫化鈉、硼氫化鋰、硼氫化鉀則分別釋放0.65L、0.73L、0.45L之氣體量，其中以硼氫化鋰釋出之氣體量略高。

關鍵字

硼氫化合物 ； 高儲氫量 ； 水解反應

並列摘要

Hydrogen energy utilization exhibits low pollution and clean features, and it is possible to fuel a car. Based on these characters, therefore, it will play a role of reducing greenhouse effect. Borane as a chemical hydrogen storage material has high hydrogen content, can release hydrogen with appropriate catalyst, and then to power devices through a fuel cell. Lithium borohydride (LiBH4), Potassium borohydride (KBH4), Calcium borohydride (Ca(BH4)2), Magnesium borohydride (Mg(BH4)2) and Sodium borohydride (NaBH4) were investigated in this research because of their high hydrogen capacities-LiBH4:18.4wt%, KBH4:7.4wt.% , Ca(BH4)2:12wt%, and 15wt% for Mg(BH4)2. We studied their hydrogen release rate by given various fuel weight and aqueous concentration through hydrolysis reaction experiments. The results show NaBH4 has highest hydrogen release rate with the 10g of fuel weight at 2 wt% aqueous concentration. NaBH4, LiBH4, and KBH4 have similar hydrogen release rate, while Ca(BH4)2 and Mg(BH4)2 have slower rates. Besides, in terms of the hydrogen volume as released, the volume of hydrogen released from LiBH4 is higher than those of the other two, the volumes of which are LiBH4:0.73L, NaBH4:0.65L, KBH4:0.45L.

並列關鍵字

Borane ； High hydrogen capacity ； Hydrolysis reaction