本研究係以異相共沸蒸餾的方式穩態模擬純化回收醋酸。此系統進料由醋酸(HAc)、水(H2O)、乙酸甲酯(MA)、及對位二甲苯(PX)組成,存在三種共沸物,分別為均相HAc-PX共沸物,其共沸溫度115.2℃、均相H2O-MA共沸物,其共沸溫度56.66℃、及非均相H2O-PX共沸物,其共沸溫度92.29℃。因水與對位二甲苯約在92.29℃存在非均相共沸,在熱力學性質上選用了NRTL活性係數模式,並套用 Hayden和O’Connell所提的理論,進行模擬。 This work is done by simulator to purify acetic acid by heterogeneous distillation at steady state.The feed compositions are Acetic acid, H2O, Methyl Acetate, and P-xylene. This work has the result of three azeotropies. One is the homogeneous azeotrope of HAc-PX, its azeotropic temperature is 92.2℃, another is the homogeneous azeotrope of H2O-MA, its azeotropic temperature is 56.66℃, and the other is heterogeneous azeotrope of PX-H2O, its azeotropic temperature is 92.29℃. Because of H2O-PX has heterogeneous azeotropic point at 92.29℃, this work were conducted with a modified NRTL model. The VLE and VLLE data were correlated by the activity coefficient models of NRTL with the consideration of the association by Hayden and O’Connell in the vapor phase.