Improving biodiesel fuel properties by modifying fatty ester composition
Improving biodiesel fuel properties by modifying fatty ester composition
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DOI：
10.1039/b903941d
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发表时间：
2009-01-01
影响因子：
32.5
通讯作者：
Knothe, Gerhard
中科院分区：
文献类型：
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作者：
Knothe, Gerhard
生物柴油是石油衍生柴油的替代品，由植物油、动物脂肪或其他原料(如用过的食用油)的烷基酯组成。生物柴油的脂肪酸组成与其原料的脂肪酸组成相一致。大多数常见原料的脂肪酸谱主要由五种C-16和C-18脂肪酸组成，即棕榈酸(十六酸)、硬脂酸(十八酸)、油酸(9(Z)-十八烯酸)、亚油酸(9(Z)、12(Z)-十八碳二烯酸)和亚麻酸(9(Z)、12(Z)、15(Z)-十八碳三烯酸)，少数油类除外，如椰子油，它含有大量的C-12-C-16或其他饱和酸。尽管生物柴油在许多方面具有石油衍生柴油的优势或竞争力，但几乎所有由这些油生产的生物柴油燃料，特别是甲酯，都存在低温性能差或氧化稳定性不足等问题。相当多的研究集中在解决或缓解这些问题上，并开发了五种方法。除了使用添加剂的方法外，还研究了通过改变油的酒精或脂肪酸组成来改变脂肪酸酯组成的方法。改变脂肪酸组成可以通过物理手段、对原料进行基因改造或使用不同脂肪酸组成的替代原料来实现。在某些情况下，方法可能会重叠。本文简要总结了目前使用的五种方法，重点介绍了改变生物柴油脂肪酯组成的方法。
Biodiesel is an alternative to petroleum-derived diesel fuel composed of alkyl esters of vegetable oils, animal fats or other feedstocks such as used cooking oils. The fatty acid profile of biodiesel corresponds to that of its feedstock. Most common feedstocks possess fatty acid profiles consisting mainly of five C-16 and C-18 fatty acids, namely, palmitic (hexadecanoic), stearic (octadecanoic), oleic (9(Z)-octadecenoic), linoleic (9(Z), 12(Z)-octadecadienoic) and linolenic (9(Z), 12(Z), 15(Z)-octadecatrienoic) acids, with the exception of a few oils such as coconut oil, which contains high amounts of saturated acids in the C-12-C-16 range or others. While in many respects biodiesel possesses advantages or is competitive with petroleum-derived diesel fuel, virtually all biodiesel fuels, typically the methyl esters, produced from these oils have performance problems such as poor low-temperature properties or insufficient oxidative stability. Considerable research has focused on solving or alleviating these problems and five approaches have been developed. Besides the approach of using additives, changing the fatty ester composition by either varying the alcohol or the fatty acid profile of the oil have been studied. Changing the fatty acid profile can be achieved by physical means, genetic modification of the feedstock or use of alternative feedstocks with different fatty acid profiles. In some cases approaches may overlap. This article briefly summarizes the five approaches currently used with an emphasis on those dealing with changing the fatty ester composition of a biodiesel fuel.