Aquifer-on-a-Chip: understanding pore-scale salt precipitation dynamics during CO2 sequestration
Aquifer-on-a-Chip: understanding pore-scale salt precipitation dynamics during CO2 sequestration
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DOI：
10.1039/c3lc00031a
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发表时间：
2013-01-01
期刊：
影响因子：
6.1
通讯作者：
Sinton, David
中科院分区：
文献类型：
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作者：
Kim, Myeongsub;Sell, Andrew;Sinton, David
在这项研究中，我们开发了一种芯片实验室方法来研究咸水层二氧化碳封存过程中的孔隙尺度盐沉淀动力学，这是这种碳管理策略的挑战。通过与当地地质构造相匹配的微流体网络来跟踪三个不同的相——二氧化碳（气体）、盐水（液体）和盐（固体）。由此产生的盐形成动态表明孔隙度下降了大约 20%，与大规模岩心研究一致。在网络尺度上，盐沉淀前沿以恒定速度移动，类似于本例中二氧化碳表观速度的 2%。在孔隙尺度上，我们观察到盐形成的两种主要类型：（1）大块晶体，其孔径约为（20-50μm），在捕获的盐水相中早期形成； (2)多晶聚集结构，其长度范围很广，在蒸发过程后期形成并从CO2-盐水界面收集/投射。这两种盐形成机制共同表现出特别容易堵塞孔隙和降低碳储存能力。
In this study, we develop a lab-on-a-chip approach to study pore-scale salt precipitation dynamics during CO2 sequestration in saline aquifers-a challenge with this carbon management strategy. Three distinct phases-CO2 (gas), brine (liquid), and salt (solid)-are tracked through microfluidic networks matched to the native geological formations. The resulting salt formation dynamics indicate porosity decreases of similar to 20% in keeping with large scale core studies. At the network scale, the salt precipitation front moves at a constant velocity, similar to 2% that of the superficial CO2 velocity in this case. At the pore-scale, we observe two dominant types of salt formation: (1) large bulk crystals, on the order of the pore size (20-50 mu m), forming early within trapped brine phases; and (2) polycrystalline aggregated structures, ranging over broad length scales, forming late in the evaporation process and collecting/projecting from the CO2-brine interface. Together, these two salt formation mechanisms show particular propensity for pore blockage and reduced carbon storage capacity.