环状化合物-甲烷水合物稳定性的分子模拟

Molecular simulation of the stability of ring compounds-methane clathrate hydrate

分子动力学模拟(MD)可为天然气以水合物形式固化提供微观分析。本文利用计算机模拟,恒温等压(NPT)系综下,分别研究了温度为273K、283K、293K,压力为2MPa条件下,环状化合物环戊烷、四氢呋喃、四氢吡喃3种促进剂对Ⅱ型甲烷水合物体系稳定性的影响。结果表明:添加促进剂可使天然气水合物在温和条件下稳定存在;当温度升高,体系稳定性下降;相同条件下,促进作用排序为环戊烷四氢呋喃四氢吡喃;客体分子直径与晶穴直径之比接近1时体系较稳定。

Molecular dynamics simulation(MD)provides microscopic analysis of natural gas solidification in the form of hydrates.In this paper,using computer simulation and isothermal-isobaric?ensemble(constant-NPT ensemble),the effects of three cyclic compound accelerators,cyclopentane,tetrahydrofuran and tetrahydropyran,on the stability of type Ⅱ methane hydrate system were studied under the conditions of 273K,283K,293K and 2MPa.The results show that the addition of accelerator can make the natural gas hydrate stable under unharsh conditions;when the temperature increases,the stability of the system decreases;under the same conditions,the contribution to the stability is cyclopentane>tetrahydrofuran>tetrahydropyran;and when the ratio of guest molecule diameter to crystal hole diameter is close to 1,the system is relatively stable.