关键词: 活度系数方程, 芳烃, 抽提蒸馏, 工艺模拟, PRO/Ⅱ软件, 相平衡, 热力学模型, 无限稀释活度系数

Abstract:

According to the process of extraction distillation in aromatics extraction unit, the separation processes of extraction distillation column, non-aromatic distillation column and solvent recovery column were studied using PRO/Ⅱ simulation software. The models of vapor-liquid equilibrium and liquid-liquid equilibrium for highly non-ideal system were selected. The activity coefficient equation parameters and infinite dilution activity coefficient required for the phase equilibrium calculation model of several important components, such as aromatics, olefins and solvents, were imported through manual external input, the calculation range of the models of vapor-liquid phase equilibrium was widened. The simulation modules of column equipment, such as extraction distillation column was estabilished. A complete simulation software package for the extraction distillation process of aromatics extraction unit was established. After comparison, the deviation between the simulation results and the reference data was acceptable. The software package can be used for the engineering design of the aromatics extraction unit. The variation of infinite dilution activity coefficient of alkanes, olefins, cycloalkanes and aromatics in sulfolane with various factors was summarized.

Key words: activity coefficient equation, aromatic hydrocarbon, extraction distillation, process simulation, PRO/Ⅱ simulation software, phase equilibrium, thermodynamic model, infinite dilution activity coefficient