低硫柴油润滑性改进剂的制备与性能评价研究

发布时间：2018-01-29 04:39

  本文关键词： 抗磨 连续冷冻压滤 油酸甘油酯 合成 评定　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着环保要求的提高,柴油生产逐渐向低硫和无硫方向发展。伴随着硫元素的脱除,一些具有润滑作用的组分也被除去,柴油自身润滑性变差,使用时会造成柴油机的磨损。向柴油中加入润滑添加剂(抗磨剂)是减小磨损行之有效的方法。本文阐述了脂肪酸型和脂肪酸酯型柴油抗磨剂的制备,并评价其润滑性能。选用大豆油酸、妥尔油酸和棉籽油酸为原料,采用多级冷冻压滤法提纯油酸制备酸型抗磨剂。多级冷冻压滤的条件是:过滤压力0.2~0.4MPa,滤布孔径25μm,冷冻时间20~24小时,冷冻次数3次,一级冷冻恒温3~4℃,二级冷冻恒温-6~-8℃,三级冷冻恒温-12~-15℃,三种油酸的冷冻温度略有差异,优选在凝点附近。提纯后三种油酸的产率均在80%以上。用气相色谱对三种原料和产物进行表征,结果表明,原料中不饱和脂肪酸含量为90%左右,产物中不饱和脂肪酸的含量在99%以上,饱和脂肪酸被除去,浊点和凝点均符合酸型柴油抗磨剂技术要求。用HFRR法评定三种产物润滑性能,结果表明:在两种低硫柴油中添加量为150mg/kg时,磨斑直径均符合中石化酸型抗磨剂加剂柴油润滑性不大于420μm的要求。酯型抗磨剂主要是不饱和脂肪酸多元醇酯。以对甲苯磺酸为催化剂,甲苯为携水剂,油酸和甘油为原料合成了二油酸甘油酯与三油酸甘油酯的混合物。实验考察了摩尔比、反应时间、反应温度和催化剂用量对酯化率的影响,并通过红外光谱对产品结构进行表征。结果表明,适宜的反应条件是:反应原料物质的量比n(丙三醇):n(油酸)=0.7:1;反应温度155~160℃;反应时间9h;催化剂用量5%;携水剂用量20%,在此条件下油酸的酯化率达99.4%,产物的酸值小于2mgKOH/g。用HFRR法评定产物润滑性能,结果表明:在低硫柴油中添加150mg/kg时,两种柴油的磨斑直径从分别从598μm和580μm降至386.6μm和377.4μm,符合中石化标准。制备的抗磨剂性质稳定。分别向两种评定柴油中加入制备的抗磨剂,添加量为150mg/kg时,加剂柴油的粘度、密度、氧化安定性和低温流动性几乎不变。添加酯型抗磨剂对柴油酸度几乎无影响,添加酸型抗磨剂后,柴油酸度明显增大,仍低于7mgKOH/100mL的国家标准。
[Abstract]:With the improvement of environmental protection requirements, diesel oil production is gradually developing towards the direction of low sulfur and no sulfur. With the removal of sulfur elements, some lubricating components have also been removed, and the lubricity of diesel itself has become worse. Adding lubricating additive (antiwear agent) to diesel oil is an effective way to reduce wear. The preparation of fatty acid type and fatty acid ester type diesel antiwear agent is described in this paper. The lubricating properties of soybean oleic acid, tul oleic acid and cottonseed oil acid were evaluated. The acid antiwear agent was prepared by using multistage freezing pressure filtration method to purify oleic acid. The conditions of multistage freezing pressure filtration were as follows: filtration pressure 0.2n 0.4MPa, filter cloth aperture 25 渭 m, freezing time 20g / 24 hours. The freezing temperature of the three oleic acids was slightly different. The freezing times were 3 times, the primary freezing temperature was 34 鈩，

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