[论文解读] Carbon mineralization in CO2-seawater-basalt systems: Reactive transport dynamics and vesicular pore architecture controls

Mohammad Nooraiepour, Mohammad Masoudi+1 more|arXiv (Cornell University)|Jan 2, 2026

CO2 Sequestration and Geologic Interactions被引用 1

一句话总结

该研究利用带CO2酸化海水的通流水实验和玄武岩玻璃，表明矿化过程受成核控制且具有随机性，受滞留时间和多泡孔结构影响，海水相较淡水降低矿化效率。

ABSTRACT

Carbon mineralization in basaltic rocks may offer rapid, permanent \ce{CO2} storage, yet fundamental controls on reactive transport and precipitation patterns remain poorly understood. This study integrates flow-through experiments at 80\degree C using \ce{CO2}-acidified seawater with geochemical simulation and multi-scale pore imaging to elucidate mineralization dynamics in basaltic glass. Results reveal that carbonate precipitation is nucleation-controlled and stochastic rather than growth-controlled and deterministic, with isolated accumulations forming randomly despite continuous supersaturation. Residence time exerts primary control: reducing flow rate from 0.05 to 0.005\,mL/min proved necessary for visible precipitation. Post-experiment analyses identified calcium carbonate and smectite phases. Multi-scale characterization of three basalt facies revealed that connected porosity fractions (1.3--32\%) differ significantly from total porosity (18--42\%), demonstrating that network topology controls permeability. Micro-CT analysis revealed that pore coordination numbers in basalts (modal = 2) were notably lower than those in reservoir sandstones, creating serial flow paths that are vulnerable to catastrophic permeability loss from modest precipitation. Precipitation-induced clogging scenarios were proposed, where distributed small precipitates cause more severe permeability degradation than large accumulations. The use of seawater complicates geochemistry and reduces mineralization efficiency compared to freshwater. Findings emphasize the need for probabilistic reactive transport modeling frameworks and realistic pore topologies, which are fundamentally different from conventional CCS operations.

研究动机与目标

• 澄清在CO2带电海水条件下，停留时间（对流）如何影响玄武岩岩石中碳酸盐矿化
• 评估多孔玄武岩孔隙结构如何控制反应传输与矿物沉淀模式
• 识别在海水条件下玄武岩中形成的矿物相
• 评估对玄武岩承载的CO2储存的概率性反应传输建模的影响

提出的方法

• 80 °C 条件下的通道柱反应器实验，使用CO2酸化海水，流速为两档0.05和0.005 mL/min
• 碎珊瑚石钙碳酸盐与玄武岩玻璃构成两区反应器以研究Ca2+可用性与玄武岩溶解
• 使用PHREEQC v3及CarbFix数据库进行对流、溶解与矿物沉淀的地球化学建模
• 多尺度孔隙成像（微CT）与孔隙网络建模以表征多泡孔隙度及连通性
• 实验后进行XRD、XRF、SEM-EDS以识别矿物及沉淀物的时空分布

实验结果

研究问题

• RQ1 流体滞留时间如何影响在CO2带电海水与玄武岩玻璃相互作用中的碳酸盐矿化动力学及空间分布？
• RQ2 多泡及连通孔隙结构在玄武岩的反应传输与矿物沉淀中扮演何种角色？
• RQ3 在这些条件下形成哪些碳酸盐与次级矿物，它们与饱和状态及pH演化有何关系？
• RQ4 成核与生长控制如何影响玄武岩-海水体系中的矿化效率？
• RQ5 海水（相较于淡水）如何影响矿化效率与反应路径？

主要发现

• 可见的碳酸盐沉淀需要较低的流速（0.005 mL/min）和更长滞留时间；在0.05 mL/min下未观察到宏观沉淀
• 沉淀受成核控制且具有随机性，沿柱状体形成的孤立碳酸盐聚集而非均匀生长
• 方解石为主沉淀物；其他超饱和碳酸盐包括白云石、菱镁矿和海石榴石，而海石榴石仍处于低饱和状态
• 连通孔隙度（1.3–32%）不同于总孔隙度（18–42%），表明网络拓扑支配渗透性与流动路径
• 孔隙尺度分析显示沉淀集中在边缘区域及多泡/空腔特征内，可能引发堵塞与渗透性降解
• 海水使地球化学更加复杂且低于淡水下的矿化效率；需要一个概率性反应传输框架