生質柴油規範及測試方法的評析

Assessment of the Specifications and Test Methods of Biodiesel

許惠美(Huei-Mei Syu)

指導教授 ： 劉宣良 ； 陳奕宏

國立臺北科技大學/工程學院/化學工程研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00260

摘要

生質柴油在美國材料試驗協會ASTM D6751中則定義為：「經植物油或動物油脂所衍生的長鏈脂肪酸之單烷基酯類燃料」。在美國以大豆油而在歐洲用菜籽油轉酯產製生質柴油。生質柴油還可以傳統方法從其他天然脂肪和油、如牛油、油脂及廢食用油產製。當前對於生質柴油的議題主要在利用動物製品和人類食物當材料的相關限制。
歐洲對於脂肪酸甲酯(fatty acid methyl esters, FAME)的標準於2003年被歐洲標準組織(Comité Européen de Normalisation, CEN)拿來當作汽車燃料的標準，此標準的編號為 EN 14214。該標準適用於做為柴油引擎燃料用之脂肪酸甲酯之品質及檢驗方法。此脂肪酸甲酯可以直接使用，或添加於柴油中使用。生質柴油摻配於石化柴油（BXX中XX 表示生質柴油所佔的比例，例如5 %生質柴油添加至 95 %石化柴油柴油中即為B5）。在歐盟車用柴油共同標準EN 590之2009年版規定允許添加7 %(v/v)符合EN 14214之生質柴油至車用柴油中。目前在台灣加油站販售B1生質柴油，但將於2010年販售B2生質柴油。
由於燃料本身的特性，生質柴油品質隨作為燃料的時間而變化。生質柴油氧化反應開始就會影響燃料品質，特別是溫度、 水和空氣由暴露的存儲情況影響氧化的速率。添加抗氧化劑有助降低此降解過程及改善燃料穩定性。但過度使用抗氧化劑可能會導致污泥形成。因此，必須小心選擇抗氧化劑的類型和添加量以達最大效益。車輛工業使用市售的FAME混合柴油燃料發生了一些麻煩。認為源自兩種可能性。其一為使用不符合EN 14214的FAME去摻配成EN590車用柴油品質。其二EN 14214要求尚不足夠必須調整。另外目前檢測柴油燃料氧化穩定性之檢測方法(ISO 12205, ASTM D2274)功能稍顯不足。開發新的檢驗法是必須的。
本論文主要彙整及評析比較國內外生質柴油之規範及檢驗方法。鑑於生質柴油氧化穩定性之重要性，本研究著重於探討各種氧化穩定性測試方法。此外國內油公司已建議將新的ASTM D7545氧化穩定性測試方法列為規範檢驗之替代方法，本研究亦探討該方法是否合適台灣市場所供應生質柴油氧化穩定性品質之檢測。

關鍵字

生質柴油 ； 規範 ； 測試方法 ； 氧化穩定性 ； 評析

並列摘要

The technical definition of biodiesel is “a fuel composed of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats, designated as B100, and meeting the requirements of ASTM (American Society for Testing and Materials) D6751 specification”. Biodiesel is presently produced from the esterification of lipid materials (fats and oils), such as soy oil in the United States and rapeseed oil in Europe. Biodiesel can also be produced conventionally from other natural fats and oils, such as tallow, grease, and used cooking oil. Current issues related to restrictions on rendered animal products for animal and human feed materials.
The European standard for Fatty Acid Methyl Esters (FAME) to be used as automotive fuel was set in 2003 by the Comité Européen de Normalisation (CEN) and is known under the standard number EN 14214. This standard sets limits and measurement methods for FAME, generally known as biodiesel that may be used either as a standalone fuel or as a blending component in European diesel fuel. That can be blended with petroleum diesel to create a biodiesel blend (BXX where the XX represents the percentage of biodiesel i.e. B5 means 7 % biodiesel, 95 % petroleum diesel).The CEN standard for diesel fuel, EN 590:2009, requires that all biodiesel blended in the fuel must conform to the standard EN 14214. At present, the European diesel fuel allows biodiesel to be blended at up to and including 5 %(v/v) by volume. Currently all gas stations in Taiwan sell B1, but will sell B2 in 2010.
Biodiesel quality changes over time due to the inherent nature of the fuel. Oxidation reactions begin to affect the fuel as soon as the biodiesel is created. Storage conditions, especially temperature, exposure to water and exposure to oxygen which is naturally present in ambient air, influence the rate of oxidation. Anti‐oxidant additives can help slow this degradation process and improve fuel stability up to a point. The overuse of anti‐oxidants can lead to the additional formation of sludge. Thus, care must be taken in choosing the antioxidant type and amount for maximum effectiveness.
Automobile Industries have experienced some trouble caused by FAME blended diesel fuels in the market. There are two possibilities.
1. Off-spec FAME was blended in the biodiesel which meet EN590 specification.
2. EN14214 may not be effective enough to assure the biodiesel quality. EN14214 might need to be reviewed.
Current diesel fuel oxidation stability test (ISO 12205, ASTM D2274) shows poor discrimination performance. Development of New Oxidation Stability Test Method is necessary.
This study primarily compares the domestic and international biodiesel specifications and testing methods. Because of the importance of oxidation stability to the quality of biodiesel, this study stress on the comparison of various oxidation stability testing methods. This research also tries to study whether the newly developed ASTM D 7545 rapid small scale oxidation test (RSSOT) method is proper for the test of local biodiesel.

並列關鍵字

biodiesel ； specifications ； test methods ； oxidation stability ； assessment

參考文獻

[48] 行政院環境保護署，車用汽柴油成分管制標準， 2009。

[2] ASTM International Standards worldwide, ASTM D7545-09, Standard test method for oxidation stability of middle distillate fuels – Rapid small scale oxidation test (RSSOT), 2009.

[5] European Standard Organization, EN 14214, Automotive fuels – Fatty acid methyl esters (FAME) for diesel engines – Requirements and test methods, 2003.

[8] W. Coyle, "The Future of biofuels: a global perspective," AMBER WAVES, vol.5, 2007.

[9] H. L. Li , Z. X. Zhang , S. Z. Lin and X. X. Li , "Research advances in the study of Pistacia chinensis Bunge, a superior tree species for biomass energy," Forestry Studies in China, vol.9, no. 2, 2007, pp.164−168.