复配生物柴油的抗积炭技术研究

Resistance to carbon deposition of compound biodiesel

麻疯树油不经甲酯化的化学加工、只通过调整其黏度和十六烷值复配得到生物柴油(简称复配生物柴油),以其作为燃料柴油在柴油机中燃烧产生积炭的程度比石化柴油严重得多,其根源来自原料组成中不饱和脂肪酸含量高而易产生高温氧化聚合成大分子,这是植物油脂(甚至甲酯化生物柴油)作为燃料柴油使用的一大瓶颈。采用复配生物柴油为研究对象,以SH/T 0160—1992方法,测定两类添加剂(清净剂和抗氧化剂)对降低其残炭值的作用大小。试验结果表明:两类添加剂都能不同程度地降低复配生物柴油的残炭值,其中聚醚胺D-400(清净剂)添加0.2%能降低残炭值13个百分点(未加添加剂的复配生物柴油残炭值为29%),2,5-二叔丁基对苯二酚(抗氧化剂)添加0.2%能降低残炭值10个百分点;将两类添加剂复配添加,证明有协同增效效应,如聚醚胺D-400与2,5-二叔丁基对苯二酚复配(1∶1)添加0.2%,测定其残炭值为9%,残炭值降低了20个百分点。

With biodiesel （compound biodiesel for short）obtained by only adjusting the viscosity and cetane number of Jatropha curcas L. seed oil without methyl esterification as fuel diesel, the degree of carbon deposition produced by combustion in diesel engine was more serious than fossil diesel. The reason for this was that the high content of unsaturated fatty acids in raw material was easy to oxidize and polymerize to produce macromolecule at high temperature, which was the bottleneck of vegetable oil used as fuel diesel. The effects of two kinds of additives （ detergent additive and antioxidant） on reduction of carbon residue value of the compound biodiesel were determined by SH/T 0160-1992 method. The results showed that the carbon residue values of compound biodiesel were reduced by two kinds of additives in various degrees, thirteen percentage points by 0.2% of polyether amine D - 400 （ detergent additive） and ten percentage points by 0.2% of 2,5 - di - tert - butylbenzene - 1,4 - diol（antioxidant） （ the carbon residue value of compound biodiesel without additives was 29% ）. The synergistic effect of the two kinds of additives was proved by compound experiment. For example, when 0.2% of the mixture of polyether amine D - 400 and 2,5 - di - tert - butylbenzene - 1,4 - diol （ 1 ： 1 ） was added to the compound biodiesel, the carbon residue value was 9%, reducing by twenty percentage points.