摘要
Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent for fragrances,cosmetics,food additives,and detergents,and can also be served as a moisturizer in cosmetics,showing broad application prospects.The distribution of DPG isomers in the products synthesized from PO and PG has a significant impactΔrGΔrHΔfHθΔfGθPO+PG⇌DPG PO+DPG⇌TPG PG+PG⇌DPG+H_(2)O PG+DPG⇌TPG+H_(2)O on the quality of the products.Therefore,conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation.So,in this paper,the thermodynamic parameters of PO,1,2-PG,H_(2)O,tripropylene glycol(TPG)and three isomers of DPG under different reaction conditions is calculated.Additionally,the,and lnK for four potential reactions at various reaction temperatures and pressures are calculated.By designing isodesmic reactions and combining the results of thermodynamic calculations,the and for the isomers of DPG are obtained,and the relative error is less than 7%.The results show that in the process of preparing DPG by PO and PG,when PO∶PG=1,the reaction temperature ranges from 298.15 to 413.15 K,and the pressure ranges from 101.325 to 506.625 kPa,the reactions of and are thermodynamically spontaneous.While the reactions of and are thermodynamically unspontaneous.The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa.The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions.The accuracy of the computational results is verified through experimental design,and based on this,the factors affecting product distribution are analyzed.
环氧丙烷(PO)是一种重要的石油化工原料,可用于生产丙二醇(PG)、聚醚多元醇和二丙二醇(DPG)等下游产品。其中,二丙二醇可用作香精香料、化妆品、食品添加剂和洗涤剂等的常用溶剂,还可作为化妆品的保湿剂,应用前景较广。而PO和1,2-丙二醇(PG)合成DPG产物中异构体的分布对于产品的品质有很大的影响。因此,对PO和PG合成DPG的反应进行热力学研究能够对实际操作和产物分布调控提供理论依据。本研究计算了PO、1,2-PG、水、二缩三丙二醇(TPG)以及DPG的三种同分异构体的热力学参数。计算了在不同反应条件下生成不同DPG异构体反应的∆r G,∆r H和ln K。通过设计等键反应,并结合热力学计算结果得出DPG的三种同分异构体的∆fHθ和∆fGθ,相对误差小于7%。结果表明,对于PO与PG制备DPG反应,当PO∶PG=1,反应温度在298.15-413.15 K,压力在101.325-506.625 kPa下,PO+PG⇌DPG和PO+DP G⇌TPG两个反应在热力学上是可以自发进行的,PG+PG⇌DPG+H_(2)O和PG+DPG⇌TPG+H2O两个反应在热力学上是不可能自发进行的;最优反应温度和压力为413.15 K和101.325 kPa;在标况下,三种异构体的热力学稳定性为DPG1>DPG2>DPG3。通过设计实验验证了计算结果的准确性,并在此基础上,分析了影响产物分布的因素。
出处
《燃料化学学报(中英文)》
北大核心
2026年第2期114-123,共10页
Journal of Fuel Chemistry and Technology
基金
Supported by the Natural Science Foundation of Shanxi Province(202203021221303)
the Science and Technology Major Project of Shanxi Province(202005D121002)
the Science and Technology Cooperation and Communication Project of Shanxi Province(202304041101016)。
