乳酸脱水制丙烯酸的热力学计算与分析

Thermodynamic Estimation and Analysis for Acrylic Acid by Dehydration of Lactic Acid

丙烯酸是一种重要的平台化合物,其聚合物在涂料、乳胶、黏合剂、鞣革和造纸等工业部门有着广泛的应用。采用基团贡献法计算了气态乳酸的恒压热容、标准生成焓、标准生成熵和标准生成吉布斯等热力学数据。通过对乳酸脱水制丙烯酸反应体系中的自由能变化、平衡常数和平衡转化率的计算发现,丙烯酸及主要副产物乙醛的产生都属不可逆反应,热力学上均可反应彻底,丙烯酸的平衡产率受温度影响很大,丙烯酸选择性主要受动力学控制,选择高效选择性的催化剂可以有效提高丙烯酸产率,理论上可以达到100%。

Acrylic acid is an important platform compound and it's polymer has wide range of applications such as coating,adhesives and tanning in industrial sectors.By using group contribution methods,thermodynamic data including heat capacity,standard formation enthalpy,standard formation entropy and standard formation gibbs of gaseous lactic acid were calculated.The calculated,equilibrium constants and equilibrium conversions showed that the reaction system of acrylic acid dehydration from lactic acid was a not reversible reaction.Low temperature favored the dehydration of lactic acid.The conversion of acrylic acid was mainly controlled by reaction dynamics,and a selective choice of efficient catalyst can effectively improve the yield of acrylic acid,in theory,the yield of acrylic acid could reach 100%.