TBAB半笼型甲烷水合物稳定性分子动力学模拟  

Molecular dynamics simulation of stability of TBAB semi-clathrate methane hydrate

作　　者：张强 梁海峰[1] 吉梦霞 杨琨 ZHANG Qiang;LIANG Hai-feng;JI Meng-xia;YANG Kun(College of Chemistry and Chemical Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China)

机构地区：[1]太原理工大学化学化工学院,山西太原030024

出　　处：《天然气化工—C1化学与化工》2021年第1期107-112,共6页Natural Gas Chemical Industry

基　　金：国家自然科学青年基金(51106104)。

摘　　要：天然气水合物是一种重要的清洁能源,相关实验和模拟成为研究的热点。采用分子动力学方法,在正则系综(NVT)的条件下,模拟温度为220 K、240 K、260 K、280 K和300 K和甲烷晶穴占有率为100%、75%、50%和25%条件下影响四丁基溴化铵(TBAB)半笼型甲烷水合物稳定性的因素。通过分析最终构象、径向分布函数、均方位移和氢键等参数,发现温度越低,甲烷占有率越高,水分子偏离初始位置的位移越小,水合物的稳定性越好;温度在260 K以下时,晶穴占有率是影响水合物稳定性的主要因素,晶穴占有率在75%以上时,温度对水合物的稳定性影响占主导因素。Natural gas hydrate(NGH)is an important clean energy,and related experimental and simulation research has become a hot spot.In this paper,molecular dynamics method was used to study the factors affecting the stability of tetrabutylammonium bromide(TBAB)semi-clathrate methane hydrate under the conditions of canonical ensemble(NVT)at temperature of 220 K,240 K,260 K,280 K and 300 K,and methane occupancy of 100%,75%,50%and 25%.Through the analysis of the final conformation,radial distribution function,mean square displacement and hydrogen bond,it is found that the lower the temperature,the higher the methane occupation,the smaller the displacement of water molecules from the initial position,and the better the stability of hydrate.When the temperature is below 260 K,the cage occupancy is the main factor affecting the stability of hydrate,and when the cage occupancy is more than 75%,the influence of temperature on the stability of hydrate is the dominant factor.

关 键 词：甲烷水合物 四丁基溴化铵(TBAB) 半笼 分子动力学 稳定性 晶穴占有率 

分 类 号：TE8[石油与天然气工程—油气储运工程]