Loring John S, Qafoku Odeta, Thompson Christopher J, McNeill Ashley S, Vasiliu Monica, Dixon David A, Miller Quin R S, McGrail B Peter, Rosso Kevin M, Ilton Eugene S, Schaef Herbert T
Pacific Northwest National Laboratory, Richland, Washington 99352, United States.
Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States.
Environ Sci Technol. 2021 Aug 17;55(16):11192-11203. doi: 10.1021/acs.est.1c00275. Epub 2021 Aug 3.
We used IR and XRD, with supporting theoretical calculations, to investigate the swelling behavior of Na-, NH-, and Cs-montmorillonites (SWy-2) in supercritical fluid mixtures of HO, CO, and CH. Building on our prior work with Na-clay that demonstrated that HO facilitated CO intercalation at relatively low RH, here we show that increasing CO/CH ratios promote HO intercalation and swelling of the Na-clay at progressively lower RH. In contrast to the Na-clay, CO intercalated and expanded the Cs-clay even in the absence of HO, while increasing fluid CO/CH ratios inhibited HO intercalation. The NH-clay displayed intermediate behavior. By comparing changes in the HOH bending vibration of HO intercalated in the Cs-, NH-, and Na-clays, we posit that CO facilitated expansion of the Na-clay by participating in outer-sphere solvation of Na and by disrupting the H-bond network of intercalated HO. In no case did the pure CH fluid induce expansion. Our experimental data can benchmark modeling studies aimed at predicting clay expansion in humidified fluids with varying ratios of CO and CH in real reservoir systems with implications for enhanced hydrocarbon recovery and CO storage in subsurface environments.
我们利用红外光谱（IR）和X射线衍射（XRD）并辅以理论计算，研究了钠蒙脱石、铵蒙脱石和铯蒙脱石（SWy-2）在水、二氧化碳和甲烷的超临界流体混合物中的膨胀行为。基于我们之前对钠基粘土的研究工作，该研究表明在相对较低的相对湿度下，水有助于二氧化碳的插层，在此我们表明，提高二氧化碳/甲烷的比例会促进钠基粘土在逐渐降低的相对湿度下的水插层和膨胀。与钠基粘土不同，即使在没有水的情况下，二氧化碳也能插层并使铯基粘土膨胀，而增加流体中二氧化碳/甲烷的比例会抑制水的插层。铵基粘土表现出中间行为。通过比较插层在铯基、铵基和钠基粘土中的水的O-H弯曲振动变化，我们认为二氧化碳通过参与钠的外层溶剂化以及破坏插层水的氢键网络，促进了钠基粘土的膨胀。在任何情况下，纯甲烷流体都不会引起膨胀。我们的实验数据可为建模研究提供基准，这些建模研究旨在预测实际储层系统中不同二氧化碳和甲烷比例的湿润流体中粘土的膨胀情况，这对提高碳氢化合物采收率和地下环境中的二氧化碳封存具有重要意义。
