摘要
采用激光拉曼光谱技术在1℃,5 MPa条件下原位测试了3种瓦斯气样(CO2,CH4和N2的百分比分别为70∶16∶14;75∶11∶14;80∶6∶14)水合过程,分别获取了其水合反应初始时刻气相与结束时刻水合物相的拉曼光谱图,探讨了其拉曼光谱特征。客体分子的振动模式及其Raman位移表明,瓦斯气样1,2分别合成CO2-CH4水合物,而气样3仅合成CO2水合物。基于客体分子Raman谱带面积比,结合"松笼-紧笼"及Van der Waals-Platteeuw模型,定量分析了3种瓦斯水合物晶体孔穴占有率、水合指数等参数。结果表明,3种瓦斯水合物样品均为Ⅰ型结构,CO2大孔穴占有率分别为75.24%,77.01%,98.70%,CH4大孔穴占有率分别为22.20%,22.64%,0,CH4小孔穴占有率分别为87.73%,91.64%和0,3种瓦斯水合物水合指数分别为6.10,5.89和7.77。
Gas hydrate were synthesized under the condition of 1 ℃ and 5 MPa by three types of gas compositions(CO2-CH4-N2,the composition ratio was 70 ∶ 16 ∶ 14,75 ∶ 11 ∶ 14 and 80 ∶ 6 ∶ 14),and the synthesized hydrate were measured by in situ Raman spectroscopy.The authors have had Raman spectrum for gas at the initial time of hydrate separation and hydrate at the end time of hydrate separation.The cavity occupancy and hydration index were calculated based on the object molecular various vibrational modes,and the Raman bands area ratio,combined with the model of "loose cage-tight cage"model and van der Waals-Platteeuw. The results show that the mixed-gas hydrates were both structure Ⅰ for the three gas samples,CO2-CH4 hydrates were synthesized by gas No.1 and No.2 gas sample,only CO2 hydrate was synthesized by No. 3 gas sample. The large cavity were occupied by CO2 are 75. 24%,77. 01% and 98. 70% respectively.The large cavity were occupied by CH4 are 22.20%,22.64% and 0 respectively,the small cavity were occupied by CH4 were 87. 73%,91. 64% and 0 respectively. Hydration index of the three hydrates were 6.10,5.89 and 7.77 respectively.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2017年第S2期385-390,共6页
Journal of China Coal Society
基金
国家自然科学基金资助项目(51774123
51704103)
黑龙江省自然科学基金资助项目(ZD2017012)
关键词
拉曼光谱
瓦斯水合物
晶体结构
孔穴占有率
水合指数
Raman spectra
coal mine gas hydrate
crystal structure
cavity occupancy
hydration index
