CO2矿化封存条件下玄武岩溶解反应速率模型

实施CO2补集与地质封存是目前降低大气中CO2含量、减轻温室效应的有效途径。在所能利用的封存方式中，CO2矿化封存最为安全、稳定。在能实施矿化封存的岩石介质中，玄武岩封存潜力巨大，且岩石溶解反应过程是矿化沉淀过程的基础；因此，研究玄武岩溶解反应速率十分必要。在构成玄武岩的单一矿物与缓冲溶剂的反应速率模型的基础上，提出不同温度下玄武岩样品在超临界CO2水溶液中的溶解速率模型，并通过室内实验，利用采自山东省临朐县的玄武岩岩心样品，在45~100 ℃、10 MPa条件下，与超临界CO2－纯水反应，并运用最小二乘法确定模型中相关参数。同时利用57 ℃、72 ℃、92 ℃ 3个温度下的模型计算值与实验值对模型进行验证，结果证明了模型的准确性和可靠性，研究结果可直接应用于CO2地质封存条件下玄武岩溶解速率的计算。

Model of Basalt Dissolution Rate Under CO2 Mineral Sequestration Conditions

Implementation of CO2 capture and sequestration has currently been proposed as an effective way to reduce CO2 emissions and alleviate greenhouse effect.CO2 mineral sequestration is the most secure and stable way among all the geological storage types and basalt has been identified as a potential host formation.Moreover, the process of rock dissolution is the basis of mineral precipitation and CO2 mineral sequestration.Therefore, it is necessary to study the dissolution rate of basalt.Previous researches concentrate on rate models for individual primary minerals in basalts under buffer solution.In this paper, we propose a dissolution rate model of basalt in supercritical CO2 solution under different temperatures.The basalt samples used in the experiments were taken from Linqu County, Shandong Province.The laboratory experiments were conducted under a range of temperatures (45-100 ℃) and 10 MPa.The related parameters in the model were calculated through least square method.Model verification were conducted using the model predicted value and experimental value under 57 ℃, 72 ℃, 92 ℃, respectively. Results show that the model is accurate and reliable, which can be directly applied for calculating basalt dissolution rate under CO2 geological sequestration conditions.