基于Raman光谱技术的瓦斯混合气水合过程定量分析

发布时间：2018-08-25 10:05

【摘要】：瓦斯水合物微观晶体结构研究对水合分离技术具有重要理论意义。利用Raman光谱技术对三种含高浓度CO2瓦斯混合气水合反应过程进行在线观测,并对水合物相Raman光谱图进行分析,获取了瓦斯水合物不同生长阶段大、小孔穴占有率,同时利用van der Waals与Platteeuw热力学统计模型间接获得水合指数等晶体结构信息。结果表明,瓦斯水合物孔穴占有率及水合指数在水合物不同生长阶段未发生较大变化,水合物相中大孔穴几乎被客体分子填满,CO2与CH4分子共同占据大孔穴,但CO2占绝大多数,达到78.58%~94.09%,CH4分子仅为4.52%~19.12%,这主要是由于两种分子间存在竞争关系且气样中CO2浓度明显高于CH4,大孔穴占有率维持在97.70%~98.68%;小孔穴占有率为17.93%~82.41%,占有率普遍偏低,且仅有CH4分子;随气样中CH4浓度增加,CH4在大、小孔穴中的占有率均有所增加,且CH4分子在大孔穴中的占有率均明显低于在小孔穴中占有率;水合物生长不同阶段水合指数为6.13~7.33,随气样中CH4浓度的增加,小孔穴占有率有所增加,致使水合指数随之降低;由于瓦斯水合物生长分布不均匀,三种气样对应的不同生长阶段水合指数均呈不规则变化。
[Abstract]:The study on the microstructure of gas hydrate is of great theoretical significance to the hydration separation technology. The process of hydration of three kinds of gas mixtures containing high concentration of CO2 gas was observed online by Raman spectroscopy, and the Raman spectrum of hydrate phase was analyzed. The occupancy rate of gas hydrate in different growth stages was obtained. At the same time, the crystal structure information such as hydration index is obtained indirectly by van der Waals and Platteeuw thermodynamic statistical model. The results show that the pore occupancy and hydration index of gas hydrate do not change greatly at different growth stages of gas hydrate. The macroporous cavities in hydrate phase are almost filled with CO _ 2 and CH4 molecules, but CO2 accounts for most of them. It is mainly due to the competitive relationship between the two molecules and the fact that the concentration of CO2 in the gas sample is obviously higher than that in the CH4, macroporous cavity at 97.70,98.68%, and the occupation rate of the small pore cavity is 17.93% and 82.41%, which is generally low, and only CH4 molecule is present. With the increase of CH4 concentration in the gas sample, the percentage of Ch _ 4 in the pores increased, and the share of CH4 molecules in the pores was significantly lower than that in the pores. The hydration index of hydrate is 6.13 ~ 7.33 in different stages of hydrate growth. With the increase of CH4 concentration in gas sample, the occupation rate of small pore cavity increases, which results in the decrease of hydration index, and the distribution of gas hydrate growth is not uniform. The hydration index of the three gas samples at different growth stages showed irregular changes.
【作者单位】：黑龙江科技大学安全工程学院;瓦斯等烃气输运管网安全基础研究国家级专业中心实验室;黑龙江科技大学建筑工程学院;
【基金】：国家自然科学基金项目(51334005,51174264,51274267,51104062) 黑龙江省普通高等学校青年学术骨干支持计划项目黑龙江科技大学研究生创新科研项目(YJSCX2014-102HKD)资助
【分类号】：O657.37;TD712.67

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