摘要乙醛缩二乙醇(乙醛缩)作为一种重要的缩醛类香料, 在日用化工、食品和饮料等行业中具有重要的应用价值。本论文采用自行设计的UV-LED恒温石英光催化反应器及微流控芯片反应器将非均相光催化反应技术应用于乙缩醛的缩醛反应体系,成功合成了乙醛缩,优化了合成反应工艺。考察了乙缩醛的气相色谱检测条件,讨论了氧气是否饱和、光强、反应时间、催化剂用量等因素对乙醛缩的产率及选择性的影响。实验结果表明:在紫外光强为1.0mw/cm2,催化剂TiO2(P25)用量为5.0g/L,温度40℃下,生成乙缩醛的条件最佳,GC产率达到0.512%,根据标准曲线得出实际产率为0.042%,为绿色、高效合成乙缩醛提供了一种新思路和新方法。44064
Abstract
Acetaldehyde Diethyl Acetal (Acetal )is an important fine spices that has very significant applicable value in daily chemical, food and beverage industry. In this paper, heterogeneous photocatalytic technology is applied to the acetal reaction in a self-designed constant temperature quartz-glass photocatalytic reactor and microfluidic chip reactor with UV-LED as light source. Acetal has been successfully synthesized, the synthetic reaction process has been optimized. In this paper,the gas chromatographic detection conditions of Acetal was optimized. And the effects of oxygen saturation, light intensity, reaction time and temperature on the yield of Acetal were investigated. The experimental results show that under the condition of light intensity bing 1.0 mw/cm2, 40℃, reaction time being 5min, the yield of Acetal is 0.512%,the yield of Acetal is 0.042% based on the low concentration of the standard curve,t is very significant that this work provides new ideas and methods for the green efficient synthesis of Acetal.
毕业论文关键词;乙醇; 纳米TiO2; 光催化缩醛反应; 乙醛缩二乙醇
Keywords:Ethanol; Nano-Titanium Dioxide; Photocatalytic Acetalization ; Acetaldehyde Diethyl Acetal
目录
目录 3
1.前言 4
2.实验部分 5
2.1主要试剂与仪器 5
2.2光催化反应器制备 6
2.2.1光催化微反应器制备 6
2.2.2恒温石英玻璃光催化反应器 7
2.3乙缩醛光催化合成 7
2.4气相色谱仪定性和定量分析 7
3.结果与讨论 8
3.1光催化乙缩醛反应 8
3.2乙缩醛的气相色谱检测 9
3.3氧气对光催化合成乙缩醛的影响 12
3.4光强对光催化合成乙缩醛的影响 13
3.5反应时间对光催化合成乙缩醛的影响 13
3.6温度对光催化合成乙缩醛的影响 14
3.7反应器对光催化合成乙缩醛的影响 14
3.8 乙醇光催化缩醛反应的机理探讨 15
4小结和展望 16
1.前言
光催化反应是光和物质之间的多种相互作用方式之一, 是光反应和催化反应的融合, 是在光和催化剂同时作用下所进行的化学反应[1]。
TiO2是最常用的半导体催化剂,具有光催化效率高、反应条件温和、无二次污染、操作简便,适用范围广等优点,在光电领域、光催化领域、污染治理以及灭菌等领域受到了广泛关注。TiO2光催化技术因为是一种真正的环境友好的绿色技术,具有广阔的应用前景。