A pore-scale lattice Boltzmann model for solute transport coupled with heterogeneous surface reactions and mineral dissolution

by Long Ju, Shusen Wang, Baochao Shan, Shuyu Sun, Bicheng Yan
Year: 2024 DOI: https://doi.org/10.1016/j.cej.2024.155191

Extra Information

Chemical Engineering Journal, 2024

Abstract

In this paper, we propose a pore-scale lattice Boltzmann model to simulate fluid flow coupled with heterogeneous surface reactions and mineral dissolution. The primary in- novation lies in the transformation of surface reactions, originally treated as a boundary condition, into a volume-source term through dimensional augmentation within the frame- work of sharp liquid-solid interfaces. This significantly simplifies the implementation, particularly for reactions occurring in porous media with intricate geometric structures. Several benchmark tests were performed to validate the accuracy of this model, including a reaction-diffusion problem in a rectangular domain, a two-dimensional reaction and dis- solution of a circular grain, as well as a three-dimensional calcite crystal dissolution in a micro-channel. All the obtained simulation results agree well with the reference solutions. In addition, a dissolution problem in a three-dimensional porous medium built with the sand pack is then investigated. Cases with different P ́eclet numbers (Pe) and Damk ̈ohler numbers (Da) were simulated, and five dissolution modes were obtained, which were finally summarized in a diagram of Pe and Da.