纳米孔隙内甲烷水合物微观分解特性  

Microscopic decomposition characteristics of methane hydrate in nanopores

作　　者：万丽华[1,2] 臧小亚[1,2] 关进安[1,2] 梁德青[1,2] Wan Lihua;Zang Xiaoya;Guan Jinan;Liang Deqing(Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,Guangzhou Guangdong 510640,China;Key Laboratory of Gas Hydrate,Chinese Academy of Sciences,Guangzhou Guangdong 510640,China)

机构地区：[1]中国科学院广州能源研究所,广东广州510640 [2]中国科学院天然气水合物重点实验室,广东广州510640

出　　处：《石油化工》2020年第2期153-159,共7页Petrochemical Technology

基　　金：国家自然科学基金项目(51576197,51676197,51661165011);广东省自然科学基金项目(2018B0303110007)。

摘　　要：采用拉曼光谱仪测定硅胶孔隙水的拉曼结构,发现纳米孔隙水分子间的吸引力增强,OH化学键削弱,孔隙水中部分DA结构转化为DDAA结构,使得硅胶孔隙水极易形成水合物。采用拉曼光谱仪测试了常压和不同温度下(263,253,243 K)的纳米硅胶孔隙内甲烷水合物的分解过程,考察了纳米尺度受限空间内甲烷水合物的微观分解特性。实验结果表明,纳米孔隙内甲烷水合物的分解过程为分解—二次形成—继续分解,直到晶体消失的过程,温度越低二次形成出现的次数越多;纳米孔隙水的结构本身十分有利于甲烷水合物的形成,是造成二次形成的内在结构条件。The Raman structure of pore water inside silica gel pores was determined by Raman spectroscopy.It was found that the attraction between the pore water molecules was enhanced,the OH chemical bond was weakened,and some DA structures in the pore water were converted into DDAA structure,which made the silica gel pore water easily form hydrate.The decomposition process of methane hydrate confined inside the nano-pores of silica gel at 263,253,243 K under atmospheric pressure was also tested by Raman spectrometer.The microscopic decomposition characteristics of methane hydrate in the nanoscale confined space were investigated.It is found that the decomposition process of methane hydrate in nano-pores can be described as decomposition-reformation-continuation decomposition and final crystal disappearance.When the temperature is lower,the more times reformation occurs.The structure of pore water is very favorable for the formation of methane hydrate,which is the internal structural cause of reformation.

关 键 词：纳米孔隙 硅胶 受限空间 二次形成 脱附 

分 类 号：TQ028.8[化学工程]