N_(2)在页岩干酪根上的吸附特征  

Adsorption Characteristics of N_(2) on Shale Kerogen

作　　者：朱元强[1,2] 靳赛赛 孙青青 ZHU Yuanqiang;JIN Saisai;SUN Qingqing(School of Chemistry and Chemical Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China;Oil&Gas Field Applied Chemistry Key Laboratory of Sichuan Province,Chengdu,Sichuan 610500,China)

机构地区：[1]西南石油大学化学化工学院,四川成都610500 [2]四川省油气田应用化学省级重点实验室,四川成都610500

出　　处：《计算物理》2021年第6期707-712,共6页Chinese Journal of Computational Physics

摘　　要：采用密度泛函理论的wB97XD方法、RDG函数方法和counterpoise correction理论,研究氮气在干酪根C_(28)H_(14)O和氮掺杂干酪根C_(27)H_(14)ON上的吸附特征。结果表明:N_(2)在干酪根上的活性吸附位点为苯环上方中心位置,吸附能在8~10 kJ·mol^(-1)之间,N_(2)和干酪根之间的相互作用主要是范德华相互作用和空间排斥作用。氮掺杂改变了干酪根的构型和电子云分布,导致含氮杂环不再是稳定的活性吸附位点,增强了排斥作用,使吸附能略有减小。研究结果对理解干酪根吸附小分子的特征有重要意义,能够为页岩气的开采提供理论支持。Density functional theory wB97XD method,RDG function method and counterpoise correction theory were used to study adsorption characteristics of N_(2) on shale kerogen C28H_(14)O and nitrogen-doped shale kerogen C_(27)H_(14)ON.It shows that the active adsorption site is located on the central position above the benzene ring for N_(2) adsorbed on both kerogen C28H_(14)O and nitrogen-doped kerogen C_(27)H_(14)ON.The adsorption energy is in the range of 8~10 kJ·mol^(-1),which shows that the main interaction between nitrogen molecule and kerogens is van der Waals interaction and steric repulsion.Nitrogen doping changes the geometric configuration and electron cloud distribution of kerogen.As a result,the nitrogen-containing heterocycle is no longer a stable active site.The adsorption energy is a little lower than that of N_(2) adsorbed on C28H_(14)O,but it is still in the range of 8~10 kJ·mol^(-1).The main interaction force between N_(2) and C_(27)H_(14)ON is still van der Waals interaction and steric repulsion.This work is significant for understanding adsorption characteristics of small molecules on kerogens.It provides theoretical support for the exploring of shale gas.

关 键 词：页岩气 干酪根 吸附 wB97XD RDG函数 

分 类 号：TG147[一般工业技术—材料科学与工程]