扩展PT状态方程在受限空间内CO_(2)-碳氢混合物的相平衡  

Phase Equilibrium of CO_(2)-Hydrocarbon Mixture in Confined Space with Extended PT Equation of State

作　　者：孟展 白恒 赵蕾 MENG Zhan;BAI Heng;ZHAO Lei(College of Petroleum and Natural Gas Engineering,Southwest Petroleum University,Chengdu 610500,China;College of Chemistry and Chemical Engineering,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]西南石油大学石油与天然气学院,成都610500 [2]西南石油大学化学与化工学院,成都610500

出　　处：《华南师范大学学报(自然科学版)》2025年第1期43-50,共8页Journal of South China Normal University(Natural Science Edition)

基　　金：国家自然科学基金项目(42472215)。

摘　　要：为了将状态方程准确应用于限域空间,通过扩展PT状态方程,系统地探讨了CO_(2)及其混合物在限域空间的热物理性质和相行为。通过引入分子与壁面间的相互作用和毛细管效应,对传统PT状态方程进行了修正。结合实验数据和分子模拟结果,开发了基于纳米孔径尺寸和分子尺寸的临界偏移模型,以描述临界特性的偏移现象。基于建立的状态方程模型结合临界偏移模型,研究了CO_(2)-nC_(10)和CO_(2)-CH_(4)二元混合体系中,界面张力随温度、压力和纳米通道尺寸的变化规律。结果表明:修正后的PT状态方程预测值与实验数据高度吻合。扩展后的状态方程在预测CO_(2)和碳氢化合物二元混合体系在纳米通道中的热物理性质和相行为方面表现出较高的准确性。该新模型为理解纳米尺度下流体的相行为提供了一个可靠的理论工具,有助于更深入地掌握CO_(2)及其混合物在限域空间中的热物理性质和相行为。In order to accurately apply the state equation to confined spaces,the thermophysical properties and phase behavior of CO_(2)and its mixtures in confined spaces have been systematically investigated by extending the Peng-Robinson state equation.The traditional PT equation of state is modified by introducing the interaction between molecules and walls and the capillary effect.Combining the experimental data and molecular simulation results,a critical migration model based on the size of nano-aperture and molecular size is developed to describe the migration phenomenon of critical characteristics.Based on the established equation of state model combined with the critical shifting model,the variation of interfacial tension with temperature,pressure,and nanochannel size in CO_(2)-nC_(10)and CO_(2)-CH_(4)binary hybrid systems was studied.It is found that the predicted value of the modified PT equation of state is in good agreement with the experimental data.The expanded equation of state shows high accuracy in predicting the thermophysical properties and phase behavior of CO_(2)and hydrocarbon binary mixed systems in nanochannels.The new model provides a reliable theoretical tool for understanding the phase behavior of the fluid at the nanoscale,and contributes to a deeper understanding of the thermophysical properties and phase behavior of CO_(2)and its mixtures in confined space.

关 键 词：受限空间 状态方程 界面张力 分子-壁面相互作用 

分 类 号：TQ013.1[化学工程]