CH4水合物在SDS和CTAB溶液中的生成特性研究
Formation characteristics of CH4 hydrate in SDS and CT AB solutions
赵婷婷 1刘远超 1狄子淳 1关斌 1蒋旭浩 1徐一帆1
作者信息
- 1. 北京石油化工学院机械工程学院,北京 102617
- 折叠
摘要
为探究不同促进剂在甲烷水合物生成过程的微观作用机理,选取动力学促进剂十二烷基硫酸钠(SDS)和热力学促进剂十六烷基三甲基溴化铵(CTAB)作为添加剂,采用分子动力学方法研究其对甲烷水合物生成速率的影响.通过分析势能变化、均方位移、径向分布函数、分子簇生长速率,发现质量分数为0.9％SDS、1.2％SDS、1.2％CTAB、1.6％CTAB的溶液均可促进水合物生成.质量分数为1.2％的SDS溶液水合物生长速率最快,且SDS促进效果优于CTAB.通过分析甲烷分子密度分布云图,发现呈阴性的SDS分子头部基团吸附了大量甲烷分子,水分子受挤压向中间聚集;CTAB含氮的头部基团朝向均相溶液,包含在不稳定的水合物笼中,形成半笼型水合物.相比之下,CTAB溶液中水合物含气率更高.
Abstract
In order to explore micro promotion mechanisms of different accelerators in the process of methane hy-drate formation,the kinetic hydrate promoter sodium dodecyl sulfate(SDS)and thermodynamic hydrate promoter cetyltrimethylammonium bromide(CTAB)were selected as additives,and their effects on the methane hydrate formation rate were studied by molecular dynamics method.By analyzing the potential energy changes,mean square displacements,radial distribution functions,molecular cluster growth rates,the results show that the solu-tions with mass fractions of 0.9％SDS,1.2％SDS,1.2％CTAB and 1.6％CTAB could promote hydrate for-mation.The SDS solution with the mass fraction of 1.2％has the fastest hydrate growth rate,and the SDS pro-motion effect is better than CTAB.By analyzing the distribution of methane density of molecular clouds,it is found that the head group of the negative SDS adsorbs a large number of methane molecules,and the water mole-cules are squeezed to the center.The nitrogen-containing head group of CTAB is oriented towards the homoge-neous solution and contained in the unstable hydrate cage,forming a semi-cage hydrate.By contrast,the gas content of hydrate in CTAB solution is higher.
关键词
分子动力学模拟/甲烷水合物/生成速率/SDS/CTABKey words
Molecular dynamics simulation/Methane hydrate/Formation rate/SDS,CTAB引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据