苯和二甲苯体系固液相平衡的数据预测与相图  

Data prediction and phase diagram of solid-liquid equilibrium for benzene and xylenes systems

作　　者：熊献金 XIONG Xianjin(SINOPEC Luoyang Engineering Co.,Ltd.,Luoyang 471003)

机构地区：[1]中石化洛阳工程有限公司,河南洛阳471003

出　　处：《合成纤维工业》2023年第5期55-60,共6页China Synthetic Fiber Industry

摘　　要：针对对二甲苯装置结晶单元中由苯和二甲苯组成的相关体系,选取了固液相平衡计算模型—Van't Hoff方程简式,利用与苯和二甲苯有关的二元和三元体系固液相平衡文献数据对该模型进行考察,利用该模型预测由苯和二甲苯组成的二元和三元体系的固液相平衡数据,并绘制三元体系的固液相平衡相图。结果表明:采用Van't Hoff方程简式计算,苯和二甲苯有关体系的液相摩尔分数的平均相对偏差为2.69%,低共熔点温度的偏差最高为0.59℃,最低为0.01℃,表明所选模型适用于由苯和二甲苯组成的体系固液相平衡计算;利用该模型预测苯-间二甲苯、苯-邻二甲苯二元体系及对二甲苯-间二甲苯-苯、对二甲苯-邻二甲苯-苯、间二甲苯-邻二甲苯-苯三元体系的固液相平衡数据,绘制了对二甲苯-间二甲苯-苯三元体系的固液相平衡相图,这些新的相平衡数据和相图均未见有文献报道,可为对二甲苯结晶相关体系的固液相平衡研究提供理论指导和依据。For the related systems of benzene and xylenes in the crystallization unit of p-xylene plant,a solid-liquid equilibrium calculation model,namely simplified Van't Hoff equation,was selected and investigated using literature data on solid-liquid equilibrium of binary and ternary systems composed of benzene and xylenes.The model was used to predict the solid-liquid equilibrium data of binary and ternary systems composed of benzene and xylenes,and the solid-liquid equilibrium phase diagram of the ternary system was drawn.The results showed that the calculation according to the simplified Van't Hoff equation provided the average relative deviation of the liquid phase mole fraction of 2.69% and the maximum and minimum deviation of the eutectic temperature of 0.59℃ and 0.01℃,respectively,indicating that the model was suitable for solid-liquid equilibrium calculation of the systems composed of benzene and xylenes;and this model was used to predict the solid-liquid equilibrium data of the binary systems of benzene-m-xylene and benzene-o-xylene and the ternary systems of p-xylene-m-xylene-benzene,p-xylene-o-xylene-benzene and m-xylene-o-xylen e-benzene,and the solid-liquid equilibrium phase diagram of the ternary system of p-xylene-m-xylene-benzene was plotted,and these new phase equilibrium data and diagram have not been reported in literature,which can provide theoretical guidance and basis for the study of solid-liquid phase equilibrium of p-xylene crystallization related systems.

关 键 词：苯 二甲苯 固液相平衡 数据预测 相图 

分 类 号：TQ241.1[化学工程—有机化工]