Abstract: α-Pinene has a special bicyclo and C=C structure. In order to predict the vapor-liquid equilibrium (VLE) data for the system containing α-pinene more accurately, α-pinene was divided into one bicyclo[3.1.1]hept-2-ene and three CH₃ according to the theory of UNIFAC model. With the correlation of VLE data for the binary system containing α-pinene, group interaction parameters for bicyclo[3.1.1]hept-2-ene with CH₃, C=C, ACH and ACCH₃ were obtained, which expands the application of the UNIFAC model. Comparing with the original UNIFAC model using only CH₃, C=C, ACH and ACCH₃ to predict VLE data of ternary system containing α-pinene, the average deviation of vapor composition and temperature from the prediction of VLE data by new group parameters are smaller than that by the original group parameters, indicating that the new group for α-pinene is more reasonable.

Key words: vapor-liquid equilibrium, activity coefficient, model, group contribution method, prediction, α-pinene

摘要： α-蒎烯具有一个特殊的双环双键结构。为更准确地预测含α-蒎烯体系的汽液平衡数据，利用UNIFAC模型原理对α-蒎烯进行基团重新划分，可得到一个大基团双环[3.1.1]-2-庚烯基与3个CH₃。通过对含α-蒎烯二元汽液平衡数据进行拟合，得到新基团双环[3.1.1]-2-庚烯基与CH₃、C=C、ACH、ACCH₃基团间的相互作用参数，扩大了UNIFAC模型的应用范围。与原始UNIFAC模型仅利用CH₃、C=C、ACH、ACCH₃基团预测出的含α-蒎烯三元体系汽液平衡数据进行比较，新基团模型预测的气相组成平均偏差以及温度平均偏差比原始基团模型的偏差要更小，说明新基团的划分更为合理。

关键词: 汽液平衡, 活度系数, 模型, 基团贡献法, 预测, α-蒎烯