A hybrid Lattice-Boltzmann model for hydro-electrochemical modeling and sensitivity analysis of crystallization potential in nanoporous media. Part II: application to the identification and quantification of influencing factors of phosphate saturation

This paper series considers the process of hydro-electrochemical saturation in nano-scale porous media. In Part I, we introduced a novel, synchronous, and integrated numerical model for hydro-electro-chemo-dynamics simulation and sensitivity analysis of nanoscale crystallization potential, and validated each of its components separately. In this Part II, we apply this methodology to perform the integrated simulations of complex 2D and 3D nanopore systems that exhibit electrochemical, hydrodynamic, and crystallization phenomena, in pair with sensitivity analysis. The phenomenon chosen for this analysis is the formation of octa-calcium phosphate in the calcium silicate hydrate. A reactive Navier–Stokes–Poisson–Nernst–Planck equation system for three ions types in the moving fluid and in the presence of a dynamic electric field is discretized using lattice Boltzmann methods. Using automatic differentiation, simplified two-dimensional models of open and blind pores as well as a three-dimensional μCT scan of a porous rock are investigated with respect to the influences
of electric surface potential, pore width and length, carrier fluid velocity and ion concentrations on octacalcium phosphate saturation. ... mehrThese simulations reveal new previously unknown insights into the crystallization process in nanopores—specifically, that narrow long blind pores with higher surface electric potential promote saturation probability. Moreover, large geometries with bigger pore systems accumulate more ions in their center locally in comparison to the smaller systems.