University of Aberdeen, School of Engineering, Elphinstone Road, AB24 3UE Aberdeen, United Kingdom; Curtin University, Discipline of Petroleum Engineering, 26 Dick Perry Avenue, 6151 Kensington, Australia.
Curtin University, Discipline of Petroleum Engineering, 26 Dick Perry Avenue, 6151 Kensington, Australia.
J Colloid Interface Sci. 2022 Feb;607(Pt 2):1226-1238. doi: 10.1016/j.jcis.2021.09.076. Epub 2021 Sep 17.
Despite the broad range of interest and applications, controls on the electric surface charge and the zeta potential of silica in contact with aqueous solutions saturated with dissolved CO at conditions relevant to natural systems, remains unreported. There have been no published zeta potential measurements conducted in such systems at equilibrium, hence the effect of composition, pH, temperature and pressure remains unknown. We describe a novel methodology developed for the streaming potential measurements under these conditions, and report zeta potential values for the first time obtained with Fontainebleau sandstone core sample saturated with carbonated NaCl, NaSO, CaCl and MgCl solutions under equilibrium conditions at pressures up to 10 MPa and temperatures up to 40 °C. The results demonstrate that pH of solutions is the only control on the zeta potential, while temperature, CO pressure and salt type affect pH values. We report three empirical relationships that describe the pH dependence of the zeta potential for: i) dead (partial CO pressure of 10 atm) NaCl/NaSO, ii) dead CaCl/MgCl solutions, and iii) for all live (fully saturated with dissolved CO) solutions. The proposed new relationships provide essential insights into interfacial electrochemical properties of silica-water systems at conditions relevant to CO geological storage.
尽管人们对电表面电荷和与溶解的 CO 饱和水溶液接触的二氧化硅的动电电势有广泛的兴趣和应用，但在与自然系统相关的条件下，对其控制仍然没有报道。在这些系统中，没有在平衡条件下进行过已发表的动电电势测量，因此组成、pH 值、温度和压力的影响仍然未知。我们描述了一种新的方法学，用于在这些条件下进行流动电势测量，并首次报告了在高达 10 MPa 的压力和高达 40°C 的温度下，用 Fontainebleau 砂岩岩心样品饱和的碳酸化 NaCl、NaSO、CaCl 和 MgCl 溶液在平衡条件下获得的动电电势值。结果表明，溶液的 pH 值是动电电势的唯一控制因素，而温度、CO 压力和盐的类型影响 pH 值。我们报告了三个经验关系，描述了动电电势对 pH 值的依赖性：i）死（CO 分压为 10 大气压）NaCl/NaSO，ii）死 CaCl/MgCl 溶液，iii）对所有活（完全溶解 CO 饱和）溶液。提出的新关系为 CO 地质储存相关条件下的二氧化硅-水系统的界面电化学性质提供了重要的见解。
