等容条件下H_2O-CO_2-CH_4混合流体的高温拉曼光谱就位分析

An in-Situ Raman Spectroscopy Study of Isochoric H_2O-CO_2-CH_4 Fluids under High Temperature

以合成包裹体作为腔体 ,用显微激光拉曼探针就位分析了H2 O CO2 CH4混合流体的高温特性。研究结果表明 ,在高温下 ,CH4和CO2 相互之间对各自拉曼光谱的影响不大 ,水分子对它们的拉曼峰有比较大的影响。在等容条件下 ,流体均一前 ,随着温度的升高 ,水分子的氢键几乎呈线性减少 ,均一为气相的流体 ,水分子伸缩振动拉曼峰的变化与一般气体变化相似 ;随着温度升高 ,体系压力的增加 ,最大峰频率呈很微小的降低趋势。均一为液相的流体中的水分子 ,在均一温度时 ,氢键变化发生了转折 ,均一后流体中水分子的氢键受温度的影响比均一前明显要小 ,在测量的最高温度 5 2 0℃ ,水分子存在着一定的氢键作用。一直到拉曼光谱测量的最高温度 5 80℃还未均一的流体 ,液相中水分子存在比较强的氢键作用。

The characteristics of the CH 4-CO 2-H 2O fluid at high temperature were studied by Raman spectroscopy.The results show that the Raman spectra of CH 4 and CO 2 do not influence each other,but they are both affected by H 2O at high temperature.The hydrogen bonding of water decreases linearly before it becomes homogenous under isochoric condition.As the fluid becomes a homogenous gas,the Raman spectroscopy has little change with temperature.The hydrogen bonding of water,however,still remains in the homogenous liquid,even at the highest temperature of 520 ℃ in experiment.For the homogenous fluid at the highest temperature of 580 ℃ during measurement,the hydrogen bonding of liquid water remains relatively stronger.