基于PR立方型状态方程普遍化温度函数的研究与评价

Research and evaluation on generalized alpha functions based on PR EoS

用11类70种非极性、弱极性和极性物质的实验蒸汽压数据对适用于Peng-Robinson状态方程(PR EoS)的17种普遍化温度函数对蒸汽压的预测能力进行了评价。根据各类物质蒸汽压预测结果平均相对偏差评价普遍化温度函数的预测能力。结果表明,Robinson-Peng (1978)、汪萍(2004)和Li-Yang (2011)温度函数能够准确预测烷烃、芳烃、气体和卤代烃类物质的蒸汽压,但对弱极性和极性的醇、醚、酯、酸、水等物质的预测结果不如Forero (2016)温度函数准确。以偏心因子和极性因子普遍化的温度函数对醇、酸、水等极性物质蒸汽压的预测结果明显优于仅以偏心因子普遍化的温度函数。

17 generalized alpha functions for Peng-Robinson equation of state(PR EoS) were evaluated using the vapor pressures of 11 kinds of non-polar, weakly polar and polar compounds. The estimative abilities of the generalized alpha functions were compared according to the average absolute deviation of each kind of compounds.The results indicated that the vapor pressures of alkanes, aromatic hydrocarbons, gases and halogenated hydrocarbons can be accurately predicted with Robinson-Peng(1978), Wang(2004) and Li-Yang(2011) alpha function. However, the predictions of vapor pressures for weakly polar and polar compounds, such as alcohols,ethers, esters, acids, and water, with Robinson-Peng(1978), Wang(2004) and Li-Yang(2011) alpha function were less accurate than that predicted with Forero(2016) alpha function. In conclusion, the generalized alpha functions with acentric factor and polar factor as variables are more accurate than that generalized only with acentric factor for the prediction of vapor pressures of polar compounds, such as alcohols, acids and water.