摘要
麻疯树油直接用作柴油机燃料在单缸柴油机中长期燃烧,积炭和结焦较为严重。为探究其产生机理,对麻疯树油进行脱胶及蒸馏实验,测定其残炭值与实际胶质含量,并对脱胶麻疯树油、残炭物和实际胶质的红外光谱进行了测定。结果表明:油中胶质是产生积炭的原因之一;麻疯树油的平均相对分子质量随蒸馏时间延长而增大,而其不饱和度呈下降趋势;麻疯树油产生积炭或结焦趋势与其不饱和度有关,添加抗氧化剂可降低麻疯树油的残炭值及实际胶质含量;在麻疯树油中添加属Lewis碱的清净剂,可有效降低残炭值,这表明积炭形成与碳正离子芳构化机理有关;实际胶质的红外光谱图指纹区有1个中等强度的醚键吸收峰产生,证明了麻疯树油在氧参与下存在自由基聚合,产生容易结焦的加聚大分子。残炭物的红外光谱图第三峰区有芳环吸收,芳构化产物是产生积炭的高碳氢比前驱物。
When Jatropha oil was used directly as diesel fuel to burn in a single cylinder diesel engine for a long time, the carbon deposit and coking were serious. In order to explore its mechanism, the degumming experiment and distillation experiment of Jatropha oil were carried out and the carbon residue value and content of actual gum were determined. The infrared spectrum of the degummed Jatropha oil, carbon residue materials and actual gum were determined. The results showed that the gum in oil was one of the causes of carbon deposits. The average relative molecular weight of Jatropha oil increased and its degree of unsaturation decreased with distillation time prolonging. The tendency of Jatropha oil to produce carbon deposits or coke was related to its degree of unsaturation. The carbon residue value and the content of actual gum of Jatropha oil could be effectively reduced by adding antioxidants. The carbon residue value could be effectively reduced by adding Lewis alkali detergents in Jatropha oil, which indicated that the coke formation was associated with carbocation aromatization mechanism. The FT-IR of actual gum showed that there was a moderate intensity ether bond absorption peak in the fingerprint region. It proved that in the presence of oxygen, free radical polymerization was occurred in Jatropha oil, which was easy to coke. The FT-IR of carbon residue materials showed that there was the aromatic ring absorption in the third peaks region, and the aromatization product was the precursor of high carbon hydrocarbon.
出处
《中国油脂》
CAS
CSCD
北大核心
2017年第12期58-61,共4页
China Oils and Fats
基金
四川省教育厅项目(16CZ0010)
关键词
麻疯树油
积炭
机理
复配生物柴油
Jatropha oil
carbon deposit
mechanism
compound biodiesel
