抽采瓦斯气分离产物特性精确获取是水合分离新技术应用关键。 针对两种浓度构成的瓦斯混合气（CO2—CH4—N2）, 利用瓦斯水合分离产物Raman测试装置, 原位合成两种水合物样品并观测Raman光谱。 基于客体分子振动模式、 “松笼-紧笼”模型及Raman谱带面积比, 结合van der Waals-Platteeuw模型, 确定出水合物晶体结构, 计算出晶体孔穴占有率、 水合指数等结构参数。 结果表明, 两种瓦斯水合物样品均为Ⅰ型结构, 其大孔穴占有率分别为98.57%和98.52%, 小孔穴占有率分别为29.93%和33.87%, 小孔穴不易被客体分子填充; 两种分离产物水合指数比较接近, 分别为7.14和6.98, 均大于Ⅰ型水合物水合指数理论值。

Accurate determination of coal mine gas separation product characteristics is the key for gas separation application based on hydrate technology. Gas hydrate was synthesized from two types of gas compositions (CO2—CH4—N2). The separation products were measured by in situ Raman spectroscopy. The crystal structure of mixed-gas hydrate was determined, and the cavity occupancy and hydration index were calculated, based on the object molecular various vibrational mode, “loose cage-tight cage” model and the Raman bands area ratio, combined with the model of van der Waals-Platteeuw. The results show that the mixed-gas hydrates are both structureⅠ for the two gas samples; Large cages of mixed-gas hydrate are nearly occupied by guest molecules, and the large cavity occupancies are 98.57% and 98.52%, respectively; but small cages are not easy to be occupied, and the small cavity occupancies are 29.93% and 33.87%, respectively; hydration index of the two gas samples hydrate is 7.14 and 6.98, respectively, which is greater than the theoretical value of structure Ⅰ.