Three-dimensional numerical study of flow characteristic and membrane fouling evolution in an enzymatic membrane reactor

TL;DR

This study uses 3D numerical simulations to analyze flow dynamics and membrane fouling in an enzymatic membrane reactor, revealing how stirring speed influences shear stress and fouling evolution.

Contribution

It introduces a comprehensive 3D Euler-Euler model to simulate granular flow and membrane fouling in enzymatic reactors, validated against experimental data.

Findings

Higher stirring speeds increase shear stress on membranes.

Stirring enhances mixing and circulation in the reactor.

Fouling evolution correlates with granular material distribution.

Abstract

In order to enhance the understanding of membrane fouling mechanism, the hydrodynamics of granular flow in a stirred enzymatic membrane reactor was numerically investigated in the present study. A three-dimensional Euler-Euler model, coupled with k-e mixture turbulence model and drag function for interphase momentum exchange, was applied to simulate the two-phase (fluid-solid) turbulent flow. Numerical simulations of single- or two-phase turbulent flow under various stirring speed were implemented. The numerical results coincide very well with some published experimental data. Results for the distributions of velocity, shear stress and turbulent kinetic energy were provided. Our results show that the increase of stirring speed could not only enlarge the circulation loops in the reactor, but it can also increase the shear stress on the membrane surface and accelerate the mixing process of granular materials. The time evolution of volumetric function of granular materials on the membrane surface has qualitatively explained the evolution of membrane fouling.