2,4-TDI/共沸剂二元体系的汽液平衡数据的测定及共沸组成分析

Measurement of vapor-liquid equilibrium data and azeotropic analysis for 2,4-toluene diisocyanate +entrainer

在脱除游离甲苯二异氰酸酯(F-TDI)的共沸蒸馏研究中,缺少2,4-TDI与共沸剂的二元体系汽液平衡数据及基础热力学参数。采用自制的汽液平衡釜,测定了0.55 k Pa压力下,2,4-TDI/苯甲酸乙酯、2,4-TDI/丁二酸二乙酯、2,4-TDI/己二酸二甲酯三组二元体系的汽液平衡数据,所得数据通过了热力学一致性面积检验。借助流程模拟软件Aspen Plus对实验数据进行了回归,得到3组UNIQUAC模型参数及关联偏差,气相摩尔分数平均偏差分别为0.0067、0.0083和0.0179,平衡温度平均绝对偏差分别为0.7 K、1.2 K和0.5 K。进而对共沸体系进行了共沸分析,得到了共沸组成和共沸条件,为F-TDI的共沸分离技术提供了工艺参数。

When conducting the removal process of free toluene diisocyanate（F-TDI）from polyurethane prepolymer by azeotropic distillation, the isobaric vapor-liquid equilibrium（VLE） data and basic thermodynamic parameters for 2,4-TDI ＋ entrainer are missing. Isobaric VLE data for 2,4-TDI/ethyl benzoate（EBZ）, 2,4-TDI/diethyl succinate（DES） and 2,4-TDI /dimethyl adipate（DMA） were measured at 0.55 k Pa by using a self-made recirculation still. The binary VLE data have passed the thermodynamic consist test proposed by the area method. The parameters and regression deviations for the UNIQUAC equation were obtained by data regression with simulation system of Aspen Plus. The average deviations of vapor mole fraction were 0.0067, 0.0083 and 0.0179, and the average absolute deviations of the predicted temperature were 0.7 K, 1.2 K and 0.5 K for the three groups, respectively. Furthermore, azeotropic systems were analyzed, and the azeotropic compositions and azeotropic conditions were provided for the azeotropic distillation of F-TDI separation.