脂肪酸甲酯对生物柴油氧化性能和热值的影响

Effect of fatty acid methyl esters of biodiesel on oxidation susceptibility and heat value

采用FTIR分析了菜籽油、大豆油、小桐子油及其甲酯化之后的生物柴油在特征峰处的异同点,GCMS分析了生物柴油中主要脂肪酸甲酯含量.在3种生物柴油中分别添加了不同含量的油酸甲酯、硬脂酸甲酯,分别测定了添加前后其氧化诱导期变化以及热值变化,并使用Gaussian09计算了油酸甲酯、硬脂酸甲酯的碳氢键解离能.试验结果表明:硬脂酸甲酯对生物柴油氧化诱导期影响比油酸甲酯更加明显,模拟结果与试验结果一致;生物柴油中添加脂肪酸甲酯之后热值会随着单组分脂肪酸甲酯的增加而增加,逐渐接近于单组分脂肪酸甲酯的热值大小.

After methylation of rapeseed oil, soya bean oil and jatrophaoil, the similarities and differences ofthe characteristic peak of raw oil and methylated biodiesel samples were analyzed by FTIR.The major composi-tions of the biodiesel samples were analyzed by gas chromatography - mass spectrometry （GC-MS）.Different ra-tios of methyl oleate and methyl stearate were added into biodiesel samples respectively, then the effects of fattyacid methyl esters on the oxidative induction period and heat value were investigated.Theoretical parameter of C-H bond dissociation energies （BDEs） of methyl oleate and methyl stearate were calculated by using Gaussian09.The results show that the effect of methyl stearate on the oxidation induction period of biodiesel samples was moreobvious than that of methyl stearate,and simulation results were consistent with experimental results.After addingfatty acid methyl ester in biodiesel, the heat value increased with the increase of the adding amount of single fattyacid methyl ester, which was close to the heat value of single fatty acid methyl ester.