二氧化碳在液态甲烷中溶解过程的分子动力学研究  

Molecular dynamics investigation of dissolution of carbon dioxide in methane

作　　者：蔡伟华 高磊[1] 王嘉欣 边江[2] 王兵兵 李秋英[3] 王悦 CAI Weihua;GAO Lei;WANG Jiaxin;BIAN Jiang;WANG Bingbing;LI Qiuying;WANG Yue(School of Energy and Power Engineering in Northeast Electric Power University,Jilin 132012,China;College of Pipeline and Civil Engineering in China University of Petroleum(East China),Qingdao 266580,China;CNOOC Gas and Power Group,Beijing 100120,China)

机构地区：[1]东北电力大学能源与动力工程学院,吉林吉林132012 [2]中国石油大学(华东)储运与建筑工程学院,山东青岛266580 [3]中海石油气电集团有限责任公司,北京100120

出　　处：《中国石油大学学报（自然科学版）》2023年第4期158-167,共10页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金企业创新发展联合基金重点项目(U21B2067)。

摘　　要：带压液化天然气(PLNG)技术可显著提升LNG中CO_(2)的溶解度,但其溶解微观过程及机制尚未揭示。为此以CO_(2)和甲烷为研究对象,采用分子动力学模拟方法,系统研究不同温度下CO_(2)在液态甲烷中溶解度的变化规律与溶解机制。结果表明:CO_(2)在液态甲烷中的溶解度随着温度升高而增大,且随温度上升而增大的趋势越来越明显;CO_(2)溶解度发生变化的根本原因在于分子间的范德华力,其中的色散吸引力占据主导地位;随着温度升高,甲烷分子键长增长、CO_(2)分子键角弯曲幅度增大,二者分别从分子间距离增大与分子偶极矩的增大方面提高了分子间色散作用能,从而促进了CO_(2)的溶解。The solubility of CO_(2)in LNG can be significantly increased by the pressurized liquefied natural gas(PLNG)technology,but the microscopic processes and mechanisms of solubilization have not yet been revealed.In the present work,the changing law and solution mechanism of CO_(2)dissolving in methane under different temperatures were investigated by using the molecular dynamics method.The results show that the solubility of CO_(2)in methane increases with the increase of temperature,and the trend of increasing with the increase of temperature becomes more and more obvious.The fundamental reason for the change in CO_(2)solubility is the intermolecular van der Waals forces,of which the dispersion interaction is dominant.With the increase of temperature,the bond length of methane molecules grows and the bending angle of CO_(2)molecules increases,which increases the intermolecular dispersion interaction energy from the increase of intermolecular distance and the increase of molecular dipole moment,respectively,thereby promoting the solubility of CO_(2).

关 键 词：带压液化天然气 甲烷 二氧化碳 溶解度 分子动力学模拟 

分 类 号：TE64[石油与天然气工程—油气加工工程]