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化学学报
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化学学报 ›› 2010, Vol. 68 ›› Issue (22): 2253-2258.    下一篇

研究论文

不同浓度聚乙烯醇对甲烷水合物分解作用的分子动力学模拟

陈玉娟，王燕鸿，樊栓狮*，郎雪梅   

  1. (华南理工大学化学与化工学院 传热强化与过程节能教育部重点实验室 广州 510640)
  • 投稿日期:2010-05-13 修回日期:2010-06-21 发布日期:2010-07-22
  • 通讯作者: 樊栓狮 E-mail:ssfan@scut.edu.cn
  • 基金资助:

    中央高校基本科研业务费专项资金资助;中国科学院广州天然气水合物研究中心开放基金

Molecular Dynamic Simulation of Methane Hydrate Decomposition with Polyvinyl Alcohol at Different Concentrations

CHEN Yu-Juan, WANG Yan-Hong, FAN Shuan, LANG Xue-Mei   

  1. (Key Lab of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640)
  • Received:2010-05-13 Revised:2010-06-21 Published:2010-07-22
  • Contact: shuanshi fan E-mail:ssfan@scut.edu.cn
  • Supported by:

    the Fundamental Research Funds for the Central Universities

PDF

956

被引次数

19

采用分子动力学方法, 模拟了273.15 K下聚乙烯醇(PVA)对甲烷水合物的分解作用. 研究发现, PVA浓度为2.7 wt%时, 水分子始终在其平衡位置附近波动, 扩散系数仅为1.04×10－11 m2/s; PVA浓度为5.2 wt%时, 水合物笼型结构坍塌, 水分子以液态水的形式存在, 甲烷分子从孔穴中逸出, 聚乙烯醇的羟基在分子内部形成氢键, 形成团簇, 产生空间位阻, 阻止了水分子再生成水合物, 水分子的扩散系数1.61×10－9 m2/s; PVA浓度为7.6 wt%时, 甲烷水合物周围有部分笼型结构被破坏, 部分甲烷分子从孔穴中逸出, 水分子扩散系数为3.55×10－10 m2/s. 得出聚乙烯醇对甲烷水合物的分解作用大小为: 5.2 wt%＞7.6 wt%＞2.7 wt%, 为PVA溶液促进甲烷水合物分解实验研究提供参考.

关键词: 聚乙烯醇, 甲烷水合物, 分子动力学模拟, 分解

Methane hydrate decomposition was investigated by molecular dynamic simulation adding with polyvinyl alcohol. Three kinds of methane hydrate systems with polyvinyl alcohol concentration of 2.7 wt%, 5.2 wt%, 7.6 wt% respectively were studied. Water moleculars in methane hydrate fluctuate near the equilibrium position when polyvinyl alcohol (PVA) concentration is 2.7 wt%, with diffusion coefficient 1.04×10－11 m2/s; while at 5.2 wt% PVA solution, methane hydrate structure was disrupted, most methane escaped from the cages, with diffusion coefficient of water molecular 1.61×10－9 m2/s, showing good ability of hydrate decomposition. Hydrogen bond was observed between PVA itself, causing steric hindrance in hydrate formation. A small parts of methane hydrate cages at interface were disrupted, resulting some methane escaped, the diffusion coefficient of water molecular is 3.55×10－10 m2/s in 7.6 wt% PVA solution. As for effect on decomposition of methane hydrate, PVA concentration 5.2 wt% is the greatest, while the PVA concentration 2.7 wt% is the least. This work provides great reference value for the experimental investigation into the effect of PVA on the hydrate dissociation.

Key words: polyvinyl alcohol, methane hydrate, molecular dynamic simulation, decomposition