Mathematical modelling and numerical simulation of reverse-osmosis desalination

TL;DR

This paper develops a mathematical model and numerical simulation framework to analyze flow, transport, and salt precipitation in reverse osmosis membranes, aiming to improve understanding of process sustainability and membrane fouling.

Contribution

It introduces a reactive porous interface model with dynamic porosity and permeability, implemented in OpenFOAM, to simulate membrane scaling and clogging under various conditions.

Findings

Model effectively captures membrane fouling dynamics.

Simulation results demonstrate parameter impacts on recovery efficiency.

The approach provides a robust tool for optimizing desalination processes.

Abstract

The reverse osmosis membrane module is an integral element of a desalination system as it determines the overall performance of the desalination plant. The fraction of clean water that can be recovered via this process is often limited by salt precipitation which plays a critical role in its sustainability. In this work, we present a model to study the complex interplay between flow, transport and precipitation processes in reverse osmosis membranes, which together influence recovery and in turn process sustainability. A reactive porous interface model describes the membrane with a dynamic evolving porosity and permeability to capture the scaling and clogging of the membrane. An open-source finite-volume numerical solver is implemented within the OpenFOAM library and numerical tests are presented here showing the effect of the various parameters of the model and the robustness of the model to describe a wide range of operating conditions.