三乙酸甘油酯合成中催化剂与能耗的关键技术

Key Technologies of Catalysts and Energy Consumption in Synthesis of Bio-Based Triacetin

在生物基甘油与乙酸的酯化反应中添加催化剂,从催化剂的选择、浓度、反应时间、醋酐添加量等方面进行研究。实验结果表明,当低浓度硫酸(<1.0%)作为催化剂时,显著地缩短了甘油酯化反应时间,与无催化剂工艺相比,从22 h减少至6.0 h以内,能节省大量的酯化用能耗。制得产品的GTA含量大于99.8%、酸度小于0.0020%、色泽为10#(铂-钴)、水分为0.016%,质量指标符合YC/T 144和GB 29938等相关国家标准;采用硫酸工艺制得的产品经长期贮存,不会出现严重的“返酸”现象;通过对反应机理进行分析,证明了二乙酸甘油酯分子结构的空间位阻作用减缓了第三步的反应速率;对GTA在烟用滤嘴丝束材料的应用进行分析,证明了酸度、水分、含量之间的关系。

The catalyst technology was used for the esterification of bio-based glycerol with acetic acid,and the preparation of glycerol triacetate were investigated from the aspects of catalyst selection,concentration,reaction time and dosage of acetic anhydride.The experimental results showed that sulfuric acid was the best choice as catalyst.When low concentration sulfuric acid(<1.0%)was used as the catalyst,it could significantly reduce the time of esterification reaction.Compared with the process without catalyst,it could be reduced from 22 h to less than 6.0 h,which saved a large amount of esterification energy consumption.The content of triacetin products was more than 99.8%and the acidity was less than 0.0020%,with the color of 10#(Hazen Pt-Co)and the moisture content of 0.016%.The product quality indicators could meet the relevant national standards(YC/T 144 and GB 29938).After long-term storage,the products prepared by sulfuric acid did not appear serious acid reversion phenomenon the reaction mechanism was discussed,it was confirmed that the steric hindrance of the molecular structure of glycerol diacetate would slow down the reaction rate in the third step.The application of GTA in cigarette filter tow material was discussed,and the relationship between acidity,moisture and content was discussed.