Loodts V, Knaepen B, Rongy L, De Wit A
Université libre de Bruxelles (ULB), Faculté des Sciences, Nonlinear Physical Chemistry Unit, CP231, 1050 Brussels, Belgium.
Phys Chem Chem Phys. 2017 Jul 19;19(28):18565-18579. doi: 10.1039/c7cp01372h.
Chemical reactions can accelerate, slow down or even be at the very origin of the development of dissolution-driven convection in partially miscible stratifications when they impact the density profile in the host fluid phase. We numerically analyze the dynamics of this reactive convective dissolution in the fully developed non-linear regime for a phase A dissolving into a host layer containing a dissolved reactant B. We show for a general A + B → C reaction in solution, that the dynamics vary with the Rayleigh numbers of the chemical species, i.e. with the nature of the chemicals in the host phase. Depending on whether the reaction slows down, accelerates or is at the origin of the development of convection, the spatial distributions of species A, B or C, the dissolution flux and the reaction rate are different. We show that chemical reactions can enhance the steady-state flux as they consume A and can induce more intense convection than in the non-reactive case. This result is important in the context of CO geological sequestration where quantifying the storage rate of CO dissolving into the host oil or aqueous phase is crucial to assess the efficiency and the safety of the project.
当化学反应影响主体流体相中的密度分布时，它们可以加速、减缓甚至是部分互溶分层中溶解驱动对流发展的根源。我们对一种A相溶解到含有溶解反应物B的主体层中的完全发展的非线性状态下的这种反应性对流溶解动力学进行了数值分析。对于溶液中的一般A + B → C反应，我们表明动力学随化学物质的瑞利数而变化，即随主体相中的化学物质性质而变化。根据反应是减缓、加速还是对流发展的根源，物种A、B或C的空间分布、溶解通量和反应速率是不同的。我们表明化学反应在消耗A时可以提高稳态通量，并且可以比非反应情况诱导更强烈的对流。这一结果在CO₂地质封存的背景下很重要，在该背景下，量化CO₂溶解到主体油相或水相中的储存速率对于评估项目的效率和安全性至关重要。
