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摘 要

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摘 要

随着近年来能源发展的需求，生物柴油这种有利于环境发展的能源进入了人类的视野，在生产生物柴油的过程中，也产生了大量的甘油。而产生的巨大量的甘油无法被全部利用，于是寻找甘油的下游用途便成了重中之重，近年来碳酸甘油酯（GC）作为重要的甘油衍生物，吸引了广泛的关注。在目前的研究甘油转化成为碳酸甘油酯的反应中，开发了一系列新的固体碱催化剂来催化甘油的转化，得到碳酸甘油酯（GC），本文通过将多孔BaO和ZrO₂两种金属金属氧化物，以氧化物CeO₂作为载体，金属氧化物负载到该载体上，制备出一系列固体碱催化剂。制备好的催化剂用于甘油催化转化制备碳酸甘油酯的反应过程中。尝试不同的反应条件，如反应温度、反应时间等，通过气相色谱观测对反应的催化效果，即甘油转化率，通过比对筛选出催化活性最好的催化剂样品和最优的工艺条件。接着利用现代技术测试方法和手段，对催化剂的结构等进行表征测试，研究催化剂高效的原因。

在本文的实验过程中，选用的催化剂的制备方法为过量浸渍法。通过一系列的步骤，成功制备出了不同煅烧温度以及不同钡锆比例下的负载型固体碱催化剂。将催化剂样品放置于不同的煅烧温度中进行煅烧，并进行后续反应，考察不同煅烧温度可能造成的影响催化剂活性的效果。通过系列对比实验，可以看到，催化活性最好的催化剂是0.33BaZrO/CeO₂-600（即钡锆比为0.3，在600℃下煅烧制备得到的负载在氧化铈载体上的催化剂）。接下来观测不同工艺条件下该催化剂的效果。通过单因素实验，实验结果显示碳酸甘油酯产率最高时反应时间为10h，反应温度为85℃，反应物GL和DMC的摩尔比为1:2，催化剂用量为反应物之一的甘油质量的5%，在此条件下，通过酯化反应得到的碳酸甘油酯的产率为90.22%。催化剂表征结果表明，采用过量浸渍法合成的复合固体碱催化剂，表面碱性是影响其催化效果的最主要因素，在将BaO和ZrO₂加载到CeO₂载体上时产生各种本基强碱和超碱性位点，是催化剂的活性高的原因，这些位点的存在有利于甘油与碳酸二甲酯的酯交换反应。

关键词：金属负载；固体碱；酯交换；甘油；碳酸甘油酯

Abstract

With the demand for energy development in recent years, biodiesel, an environmentally friendly energy source, has entered the human eye. In the process of producing biodiesel, a large amount of glycerin is also produced. The huge amount of glycerol produced cannot be fully utilized, so the downstream use of glycerin has become a top priority. In recent years, glycerol carbonate (GC) has attracted extensive attention as an important glycerol derivative. In the current study of the conversion of glycerol to glycerol carbonate, a series of new solid base catalysts have been developed to catalyze the conversion of glycerol to obtain glycerol carbonate (GC). The two metal oxides of porous BaO and ZrO₂ are used herein. A series of solid base catalysts were prepared by supporting CeO₂ as a carrier and supporting the metal oxide on the support. The prepared catalyst is used in the reaction process of catalytic conversion of glycerol to produce glycerin carbonate. Try different reaction conditions, such as reaction temperature, reaction time, etc., to observe the catalytic effect of the reaction by gas chromatography, that is, the conversion of glycerol, and to select the catalyst sample with the best catalytic activity and the optimum process conditions by comparison. Then, using modern technology test methods and means, the structure of the catalyst was characterized and tested to investigate the reasons for the high efficiency of the catalyst.

In the experiments herein, the catalyst was prepared by an excessive impregnation method. Through a series of steps, the supported solid base catalysts with different calcination temperatures and different cerium-zirconium ratios were successfully prepared. The catalyst samples were placed in different calcination temperatures for calcination, and subsequent reactions were carried out to examine the effects of different calcination temperatures on the catalyst activity. Through a series of comparative experiments, it can be seen that the catalyst having the best catalytic activity is 0.33 BaZrO/CeO₂-600 (i.e., a catalyst having a cerium-zirconium ratio of 0.3, which is calcined at 600 ℃ and supported on a ruthenium oxide support). Next, the effect of the catalyst under different process conditions was observed. Through single factor experiments, the experimental results show that the highest yield of glycerol carbonate is 10h, the reaction temperature is 85℃，the molar ratio of reactant GL to DMC is 1:2, and the amount of catalyst is the mass of glycerol which is one of the reactants. 5%, under these conditions, the yield of glycerin carbonate obtained by the esterification reaction was 90.22%. The characterization results of the catalysts show that the surface basicity is the most important factor affecting the catalytic effect of the composite solid base catalyst synthesized by the excess impregnation method. When BaO and ZrO₂ are loaded onto the CeO₂ support, various base strong bases and superbases are produced. Sex sites are responsible for the high activity of the catalyst. The presence of these sites facilitates the transesterification of glycerol with dimethyl carbonate.

Keyword：Metal loading；solid base；transesterification；glycerol；glycerol carbonate

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1引言 1

1.2碳酸甘油酯的制备方法 2

1.3合成机理 4

1.4制备碳酸甘油酯的催化剂研究进展 4

1.4.1固体催化剂 4

1.4.2均相催化剂 5

1.4.3其他催化剂 6

1.4.4催化剂的选择 6

1.5本课题研究内容和研究意义 7

1.5.1研究内容 7

1.5.2研究意义 8

第二章 实验部分 9

2.1引言 9

2.2主要仪器与试剂 9

2.3实验过程 10

2.3.1固体碱催化剂的制备 10

2.3.2酯交换反应制备碳酸甘油酯 10

2.3.3碳酸甘油酯的产率测定 11

2.4催化剂表征手段 12

2.4.1 X射线衍射 12

2.4.2红外光谱 12

2.4.3扫描电镜 12

第三章结果和讨论 13

3.1催化剂最佳制备条件 13

3.1.1Ba、Zr摩尔比筛选 13

3.1.2煅烧温度的选择 14

3.2催化剂的表征结果 14

3.2.1 X射线衍射 14

3.2.2红外光谱 16

3.2.3扫描电镜 17

3.3工艺条件优化 18

3.3.1反应温度 18

3.3.2反应物摩尔比 19

3.3.3反应时间 20

3.3.4催化剂用量 21

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