基性、超基性岩: 二氧化碳地质封存的新途径

CO₂地质封存是控制全球CO₂净排放量的有效手段.自然界存在大量基性、超基性岩石的碳酸盐风化作用, 与CO₂反应生成稳定的碳酸盐矿物.影响基性、超基性岩石与CO₂反应速率的因素有温度、压力、pH值、流体流动速率以及与矿物接触的表面积等.矿物在反应过程中放热可以使碳酸盐化体系进入自我加热的良性循环, 同时控制流体的流动速率可以保持最佳温度并使反应速率最大化.蛇绿岩中的橄榄岩、大陆玄武岩和深海玄武岩在地球表层广泛分布, 可贮存大量CO₂.目前研究表明此方法在技术上可行, 经济成本上有优势.因此, 基性、超基性岩石具有封存CO₂的巨大潜力, 可以作为地质封存CO₂的新途径. 

Carbonation of Mafic-Ultramafic Rocks: A New Approach to Carbon Dioxide Geological Sequestration

Geological sequestration is an effective way to enhance the net reduction of global CO₂ emission. In nature, there is vast amount of carbonation of mafic-ultramafic rocks, reacting with CO₂ to produce stable carbonate minerals. Factors that affect carbonation reaction rates of mafic-ultramafic rocks with CO₂ include temperature, pressure, pH values, fluid flow rate, and contact surface area, etc.. Exothermic mineral reactions can drive the carbonation system into a self-heating regime. Meanwhile, controlling fluid flow rates can maintain the optimal temperature for reaction rate. Peridotites in ophiolite, continental flood basalt and deep-sea basalt are widespread on the shallow surface of the earth, providing an alternative for CO₂ storage. Current research demonstrates that both technology and economic cost are available. Therefore, mafic-ultramafic rocks have huge potential for CO₂ sequestration and it is a new approach to CO₂ geological sequestration.