A chemical reaction model in a porous medium

Ch. 032066. P. 1–8.

L I Kuzmina, Osipov Y. V.

Chemical reactions in a porous medium are found in many natural phenomena and
technological processes. Reactive substances dissolved in groundwater can significantly
change the soil strength. The precipitate formed as a result of the reaction changes the porous
medium structure and affects the porosity and permeability. A one-dimensional model of the
reaction of two reagents in a homogeneous porous medium with a linear reaction function is
considered. The model includes the mass balance equations of each reagent and precipitate,
and the kinetic equation of precipitate growth. It is assumed that the precipitate is stationary
and the growth rate of the precipitate is proportional to the reagents’ concentration. A carrier
fluid with constant concentration reagents is injected at the empty porous medium entrance.
The reaction front moves in a porous medium at a constant speed. The exact solution to the
problem is constructed by eliminating the unknown functions and lowering the equations’
order. A Riemann invariant that relates the concentration of sediment and reagents to the
system’s characteristics was found. The reaction’s numerical simulation is performed. It is
shown that, for a long time, the reagents’ concentrations and the precipitate tend to final limit
values. Sediment profiles always decrease monotonously, and the type of the profiles’
convexity changes.

Keywords: exact solutions, porous medium, one-dimensional model

In book

IOP Conference Series: Materials Science and Engineering

Vol. 913: International Scientific Conference "Construction and Architecture: Theory and Practice of Innovative Development" (CATPID-2020) - Part 1 26-30 September 2020, Nalchik, Russian Federation. , IOP Publishing, 2020.