生物柴油新型抗氧化剂的制备及动力学分析

以没食子酸和异丙醇为原料，吡啶硫酸氢盐离子液体为催化剂制备新型生物柴油抗氧化剂没食子酸异丙酯，通过单因素试验得到没食子酸与异丙醇催化酯化反应的最佳反应条件：反应温度85℃，反应时间4 h，醇酸物质的量比35:1，催化剂用量12%，该条件下酯化反应的转化率为89.1%。在此基础上对该催化酯化反应进行动力学分析，得出反应的表观活化能（E_a）为60.942 kJ/mol，频率因子（A）为7 060 313.404。在地沟油生物柴油中添加0.05%没食子酸异丙酯后，其氧化稳定性明显提升，诱导期从0.61 h增至6.34 h，已达到我国生物柴油国家标准（诱导期6 h），表明没食子酸异丙酯是一种抗氧化效果很好的新型生物柴油抗氧化剂。

Preparation and Kinetic Analysis of Novel Antioxidants of Biodiesel

A new antioxidant biodiesel isopropyl gallate was prepared by using gallic acid and isopropanol as raw materials, pyridine bisulfate ionic liquid as catalyst. Through the single factor analysis, the optimal reaction conditions of catalytic esterification reaction were obtained as reaction time 4 h at 85℃, the ratio of alcohol to acid 35:1, catalyst dosage 12%, the yield of isopropyl gallate under these conditions was 89.1%. Based on the catalytic esterification reaction dynamics analysis, the reaction apparent activation energy and the frequency were obtained as 60.942 kJ/mol and 7 060 313.404, respectively. The addition of 0.05% isopropyl gallate in gallate in gutter oil biodiesel significantly improved the oxidation stability, and the induction period increased from 0.61 h to 6.34 h, which completely reached the national standard for biodiesel(induction period 6 h). The experimental results showed that isopropyl gallate had good performance as new biodiesel antioxidant.