添加金屬污染物對生質柴油氧化穩定性之影響

由於金屬污染物(Metal contaminants)的存在會使得生質柴油的氧化穩定性(Oxidation stability)降低，本研究主要針對痲瘋油、桐油生質柴油、及以石化柴油和痲瘋油生質柴油進行不同比例摻合，探討添加金屬污染物後在常溫下長時間儲存之氧化穩定性試驗及預測模式。利用不同溫度(T)所測得的氧化穩定性數值(Induction period, IP)，在較高的測試溫度或較高的金屬污染物濃度下所得到的IP值會明顯較低，以EN 15751和EN 14112兩種氧化穩定性之檢測方法進行比較，發現使用EN 15751檢測方法所測得到的IP值大多相對於使用EN 14112所測得到的IP值略高，並皆可以用一階反應動力學來描述添加銅、錳、及鐵金屬污染物的生質柴油中天然抗氧化劑之氧化情形。隨著添加金屬污染物濃度越高，IP值和反應活化能(Activation energy)的下降會趨近於一定值。隨著化石柴油摻合的比例增加，含有金屬污染物對生質柴油降低氧化反應活化能的影響越顯著。而使用動力學模式推估所得25 oC下的IP值，會比使用ln IP與T(oC)外插所得25 oC的IP值高約1.5-7.9倍。實驗發現在室溫下長時間儲放及沒有曝氣條件，生質柴油發生變質的時間都遠大於動力學模式和用ln IP與T線性關係所推估的IP值。在室溫下長時間儲放及有曝氣條件，含銅污染物的桐油生質柴油和痲瘋油生質柴油之酸價上升時間，會較接近動力學模式預測所得的IP值。而未含金屬污染物痲瘋油生質柴油，其酸價的上升時間則較接近ln IP與T線性外插所得的IP值。

關鍵字

生質柴油；痲瘋油；桐油；金屬污染物；反應動力學；氧化穩定性；長時間儲放

並列摘要

The object of this study is to test the oxidation stability of biodiesels with various concentrations of metal contaminants including Cu, Mn, and Fe and evaluate the long time storage at ambient temperature. The oxidation stability of biodiesels was reduced with the addition of metal contaminants. The biodiesels include jatropha oil biodiesel, tung oil biodiesel, and jatropha oil biodiesel blending with diesel at various volumetric percentages. It was obvious that induction period (IP) was lower at high temperature or high concentration of metal contaminants. The IP obtained by EN 15751 was usually higher than that obtained by EN 14112. First-order reaction kinetics is adopted to invetigate the IP variation of the biodiesels. With higher concentration of metal contaminants, the decrase of IP and oxidation activation energy would approach to the constant. With higher blending ratio of diesel, the effect of metal contaminants on the decrease of activation energy becomes more remarkable. The IP predicted by the first-order reaction rate kinetics at 25 oC are 1.5-7.9 times than those predicted by the linear relationship between ln IP and T (oC). However, the IP of biodiesels in long time storage without aeration at ambient temperature is significantly longer than those predicted by first-order reaction rate kinetics and the linear relationship between ln IP and T. Furthermore, the increase time of acid value of tung oil and jatropha oil biodiesels contaminated with Cu would be close to those predicted by first-order reaction rate kinetics in long time storage under aeration condition. On the other hand, the increase time of acid value of original jatropha oil biodiesel is close to that predicted by the linear relationship between ln IP and T.

並列關鍵字

biodiesel ； jatropha oil ； tung oil ； metal contaminant ； reaction kinetics ； oxidation stability ； and long time storage.

參考文獻

[17] 許惠美，生質柴油規範及測試方法的評析，碩士論文，國立台北科技大學化學工程所，台北，2010。

[45] 羅育民，添加不同抗氧化劑對於生質柴油氧化穩定性影響之研究，碩士論文，國立台北科技大學化學工程所，台北，2010。

[77] 江宗翰，柴油摻合不同生質燃料對其油品性質影響之研究，碩士論文，國立台北科技大學化學工程所，台北，2011。

[2] 李興旺，石化柴油及添加生質柴油引擎排放多環芳香烴之特徵，國立成功大學環境工程系，碩士論文，2004。

[3] 林淵淙，生質柴油及乳化柴油對引擎排放廢棄污染減量及提昇能源效率之研究，國立成功大學環境工程學系，博士論文，2006。

國際替代計量

添加金屬污染物對生質柴油氧化穩定性之影響

未授權

主題瀏覽