甲酯型生物柴油对超低硫柴油润滑性能的影响

Improvement of lubricity of super low-sulfur diesel by methyl ester biodiesel

利用气质联用仪及红外光谱仪分析甲酯型生物柴油的组成与结构,采用高频往复试验机法(HFRR)考察蓖麻籽油生物柴油、菜籽油生物柴油及玉米油生物柴油对超低硫柴油润滑性的改善作用,并用测量显微镜分析试验球及试验片的磨斑形貌。结果表明:蓖麻籽油生物柴油组成特殊,主要为蓖麻油酸甲酯,与其他几种甲酯型生物柴油相比,除了含有酯基和双键官能团外,还含有羟基官能团;蓖麻籽油生物柴油对超低硫柴油润滑性的改善效果最佳,适宜添加量为0. 5%;菜籽油生物柴油及玉米油生物柴油的添加量需达到0. 7%才能使超低硫柴油润滑性磨斑直径降到460μm以下,满足GB 19147—2016标准要求;当蓖麻籽油生物柴油、菜籽油生物柴油及玉米油生物柴油添加量在0. 3%~1. 0%范围时,随着甲酯型生物柴油添加量的不断增大,润滑性磨斑直径、表面划痕及深度不断减小,平均摩擦系数降低,平均成膜率不断增大。

The composition and structure of methyl ester biodiesel were analyzed by GC-MS and infrared spectrometer,the improvement of lubricity of super low-sulfur diesel by castor seed oil biodiesel,rapeseed oil biodiesel and corn oil biodiesel were investigated by HFRR,and the wear scar of the test balls and test pieces were analyzed by measuring microscope.The results indicated that the castor seed oil biodiesel had a special composition,mainly ricinoleic acid methyl ester.Compared with other methyl ester biodiesel,the castor seed oil biodiesel contained hydroxyl functional groups in addition to ester groups and double bond.The castor seed oil biodiesel as lubricity enhancer showed noticeable improvement with0.5%dosage,and other biodiesels(rapeseed oil biodiesel,corn oil biodiesel)with 0.7%dosage could reduce the wear scar diameter of diesel to less than 460μm meeting the requirement of standard GB19147—2016.When the dosage of castor seed oil biodiesel,rapeseed oil biodiesel and corn oil biodiesel was in the range of 0.3%-1.0%,the diameter of lubricated wear scar,surface scratches and depths,and the average friction coefficient decreased with the increase of biodiesel dosage,while the average film formation rate increased.