摘要
随着经济的发展,能源需求日益增加,为了弥补国内少油缺气短板,页岩气的开发成为近期新能源的热点,探索页岩气储存规律是页岩气能源开发的关键所在.本文采用密度泛函理论的第一性原理方法,计算甲烷(CH_(4))在钠基蒙脱土表面和层间的吸附能,对比吸附前后的态密度和物理结构以及差分电荷密度.结果表明:钠基蒙脱土表面吸附中,甲烷最佳选择是桥位,吸附能为-0.08eV,被吸附后甲烷的键长和键角变化率均小于0.96%.层间吸附中,伴随着甲烷吸附量增加,纳基蒙脱土体积向c轴方向线性增加,a、b轴方向则变化不大.总态密度随着吸附量的增加,总能级数量也增加,甲烷分子的分波态密度峰向低能级移动.本文的研究成果,从原子角度分析了甲烷在蒙脱石表面以及层间的吸附能力,为解释页岩气在页岩储存规律提供理论依据.
With the development of economy,the demand for energy is increasing day by day.In order to make up for the shortage of oil and gas in China,the development of shale gas has become a hot spot of new energy recently.The key to the development of shale gas is to explore the law of shale gas structural storage.In this paper,the first-principles method of density functional theory is used to calculate the adsorption energy of methane(CH_(4))on the surface and between layers of sodium-montmorillonite.The state densities,physical structures and differential charge densities before and after adsorption are compared.The results show that the bridge site is the best choice for methane adsorption on sodium-montmorillonite surface.The adsorption energy is-0.08eV,and the change rates of bond length and bond angle of methane after adsorption are less than 0.96%.In the interlayer adsorption,with the increase of methane adsorption,the volume of Na-montmorillonite is increased linearly along the c axis,but changed little along the a and b-axes.With the increase of adsorption capacity,the number of total energy levels also increases,and the density peak of partial wave states of methane molecules moves to the lower energy level.The research results of this paper give the adsorption capacity of methane on the surface and interlayers of montmorillonite from the perspective of atoms,providing a theoretical basis for explaining the storage law of shale gas.
作者
方志杰
李博
宋昌辉
刘美玲
何秋芝
刘翔
莫曼
FANG Zhi-Jie;LI Bo;SONG Chang-Hui;LIU Mei-Ling;HE Qiu-Zhi;LIU Xiang;MO Man(School of Electronic Engineering,Guangxi University of Science and Technology,Liuzhou 545006,China;College of Civil and Architectural Engineering,Guangxi University of Science and Technology,Liuzhou 545006,China;Health Science Center,Guangxi University of Science and Technology,Liuzhou 545006,China)
出处
《原子与分子物理学报》
CAS
北大核心
2025年第2期8-14,共7页
Journal of Atomic and Molecular Physics
基金
国家自然科学基金(12364011,11864005)
广西科技计划项目(桂科AD20159079,AD21220147)。
关键词
钠基蒙脱土
第一性原理
甲烷
吸附
态密度
Sodium montmorillonite
First-principles
Methane
Adsorption
Density of state
