地质封存中CO_2溶解度的测量与模型研究进展

Progress in Measurement and Model on Solubility of CO_2 under Geological Sequestration Conditions

近年来CO2引起的温室效应受到了越来越多的重视,将CO2注入地下咸水层是CO2减排的选择之一。通过准确测量CO2在地下咸水中的溶解度,可以估算出CO2的地质存储量。文章对CO2在纯水和盐水中溶解度的测量方法以及热力学模型进行了综述,并根据前人实验数据总结得出CO2在纯水、NaCl水溶液以及混合盐水体系中溶解度随温度压力的变化规律。近年来迅速发展的分子模拟方法成为模型发展的主导方向,但大多数溶解度模型为经验或者半经验模型,参数缺乏明确的物理意义,误差较大,不能很好地满足CO2地下咸水层封存工程的实际需求。为了建立高精度的模型、完善溶解度理论,需要在更广的温度压力范围和组分条件下进行高精度的实验和模型研究。

In recent years,greenhouse effects caused by CO2 attract considerable attentions.Injected into underground saline aquifers is one of the options for reducing CO2 emission.Geological storage of CO2 can be estimated by accurate measurement of CO2 solubility in underground saline water.Measurement methods and thermodynamic models for CO2 solubility in pure water and saline water were reviewed.Based on the experimental data reported,CO2 solubility trend with pressure and temperature in pure water,NaCl solution and saline water respectively were summarized.Molecule simulating approach developed rapidly over the years has become main method.While most of the existing solubility models,with parameters lack of explicit physical meanings,are empirical or semi-empirical.Relative errors of most models are generally large and cannot meet the demand of CO2 underground sequestration project perfectly.In order to establish high precision models and improve the solubility theory,experiments and models should be performed in a broader range of temperature,pressure and components.