拉曼光谱研究高温高CO_2-H_2O溶液的结构与性质

In Situ Raman Spectroscopic Investigation on Structure and Property of CO_2-H_2O Aqueous Solution under High Temperature and Pressure

采用透明管式高压腔技术开展CO2-H2O体系在0~260℃,120 MPa下的原位Raman光谱研究。实验结果表明:(1)200℃以下,CO2对水的O—H伸缩振动带影响微弱;而200℃以上,CO2造成水峰蓝移,且蓝移程度CO2浓度的增加而增大;(2)CO2气体在80℃之上的两个热带明显增强。这些数据解释了高温CO2显著增加溶液的摩尔体积CO2溶解度随着温度的升高而迅速增大的原因。

The high pressure optical cell(HPC)was used for in situ Raman spectroscopic measurement on the CO2-H2 O system at pressure of 120 MPa and temperature from 0to 260 ℃.The results show that:(1)CO2has little effect on the O—H strecting vibrational band of water below 200℃,but CO2 shifts this band towards higher wavenumbers and increasing CO2 concentration further enlarges the blue shift degree;(2)The two hot bands on CO2 Femi bimodal are significantly strengthened at temperature higher than 80 ℃.These data explain the volume property that CO2 greatly increases molar volume of solutions and phase equilibrium property that solubility of CO2 in water are largely raised at high temperature.