Abstract: The calculation model and parameters of solid-liquid phase equilibrium for p-xylene crystallization related binary and above systems were selected. Based on the experimental data of liquid phase mole fraction of several binary systems containing p-xylene and eutectic point temperatures and compositions of binary, ternary and quaternary systems composed by C₈ aromatic components, the calculation models were investigated, and the calculated results of the model were in good agreement with the experimental data. The results showed that the model and parameters were suitable for the calculation of solid-liquid phase equilibrium of p-xylene crystallization related binary and above systems. Using this model, the eutectic point temperatures and compositions of binary, ternary, quaternary and quinary systems composed by toluene and C₈ aromatics components were calculated. The principle of melt crystallization technology was explained on the solid-liquid phase diagram of p-xylene and m-xylene binary system based on the calculation results of the model.

Key words: p-xylene, crystallization, solid-liquid phase equilibrium, eutectic point temperature, toluene, C₈ aromatics, melt crystallization

摘要： 针对对二甲苯结晶相关二元及二元以上多元体系,选取了固液相平衡计算模型及其相关参数。利用多个含对二甲苯的二元体系液相摩尔分数和由C₈芳烃各组分组成的二元、三元和四元体系的低共熔点温度及组成实验数据对该模型进行了考察,模型计算结果与实验数据吻合较好,表明所选模型及其相关参数适用于对二甲苯结晶相关二元及二元以上多元体系的固液相平衡计算。利用该模型计算得到了由甲苯和C₈芳烃组分组成的二元、三元、四元和五元体系的低共熔点温度及组成。利用该模型计算结果建立的对二甲苯-间二甲苯二元体系固液相图说明了熔融结晶技术的原理。

关键词: 对二甲苯, 结晶, 固液相平衡, 低共熔点温度, 甲苯, C₈芳烃, 熔融结晶