应用大分子促进剂的H型水合物储氢特性的分子动力学模拟
Molecular dynamics simulation of hydrogen storage characteristics of H-type hydrates using macromolecular promoters
武英东 1曹青 1梁海峰1
作者信息
- 1. 太原理工大学 化学工程与技术学院,山西 太原 030024
- 折叠
摘要
纯氢气水合物形成的温压条件极为苛刻(低温高压),限制了其工业应用,而氢气和甲烷混合气水合物形成的温压条件相对温和.通过恒温恒压(NPT)系综分子动力学模拟,研究了环庚酮(C7H12O)、甲基环己烷(C6H11-CH3)、1,1-二甲基环己烷(1,1-C8H16)和1,2-二甲基环己烷(1,2-C8H16)4种大分子促进剂对H型纯氢气水合物以及氢气和甲烷混合气水合物稳定性的影响.结果表明,分别应用4种大分子促进剂的H型水合物牢笼稳定性从大到小依次为1,1-C8H16、1,2-C8H16、C6H11-CH3和C7H12O.相比于纯氢气,氢气和甲烷混合气能够极大缓和热力学条件(温度升高,压力降低).两种同分异构体(1,1-C8H16和1,2-C8H16)作为大分子促进剂,对应的热力学条件表现出较大差异.在纯氢气水合物中,两种同分异构体作为大分子促进剂所需温度条件相近(270 K),而1,1-C8H16作为大分子促进剂所需压力条件(60 MPa)低于1,2-C8H16(100 MPa).在氢气和甲烷混合气水合物中,1,1-C8H16作为大分子促进剂所需温度条件(270 K)高于1,2-C8H16(260 K),所需压力条件(20 MPa)低于1,2-C8H16(40 MPa).
Abstract
The temperature and pressure conditions for the formation of pure hydrogen hydrates are extremely harsh(low temperature and high pressure),limiting their industrial applications,whereas the temperature and pressure conditions for the formation of hydrogen and methane mixture hydrates are relatively mild.The effects of four macromolecular promoters,cycloheptanone(C7H12O),methylcyclohexane(C6H11-CH3),1,1-dimethylcyclohexane(1,1-C8H16)and 1,2-dimethylcyclohexane(1,2-C8H16),on the stability of H-type pure hydrogen hydrates and hydrogen and methane mixture hydrates were investigated by means of molecular dynamics simulations using a thermostatic constant pressure(NPT)system.The results show that the cage stability of H-type hydrates with the application of the four macromolecular promoters is,in descending order,1,1-C8H16,1,2-C8H16,C6H11-CH3,and C7H12O.The mixture of hydrogen and methane is able to greatly moderate the thermodynamic conditions(temperature increases and pressure decreases)compared to that of pure hydrogen.The two isomers(1,1-C8H16 and 1,2-C8H16)show large differences in thermodynamic conditions between them as macromolecular promoters.In pure hydrogen hydrate,both isomers require similar temperature condition(270 K)as macromolecular promoters,while 1,1-C8H16 requires lower pressure condition(60 MPa)as a macromolecular promoter than 1,2-C8H16(100 MPa).In hydrogen and methane mixture hydrates,1,1-C8H16 requires higher temperature condition(270 K)than 1,2-C8H16(260 K)and lower pressure condition(20 MPa)than 1,2-C8H16(40 MPa)as a macromolecular promoter.
关键词
H型水合物/大分子促进剂/双客体小分子/储氢/分子动力学Key words
H-type hydrates/macromolecular promoters/bi-guest small molecules/hydrogen storage/molecular dynamics引用本文复制引用
基金项目
国家自然科学基金青年基金(51106104)
出版年
2024
国家科技期刊平台
NSTL
万方数据