(195a) Predicting Performance and Efficiency of Semi-Permeable Membranes with Simulation

Membranes are widely used in separation processes where particles or species ranging from a few micrometers (microfiltration) down to molecular size are separated from a stream. Well-known examples are the filtration of dust particles from flue gas, reverse-osmosis to gain drinking water from seawater or gas permeation to separate different species of gases.

While the selectivity of membranes is basically a function of its molecular formulation, overall efficiency depends in addition on system parameters like flow, pressure and temperature  In this contribution we want to show the predictive capabilities of STAR-CCM+ to model such membrane separation processes.  The performance of a membrane is investigated for two examples, where molecular functionality of the membrane is expressed by generally used modeling approaches and combined with flow behavior calculations of classical CFD.

In a first validation study a semi-permeable membrane for a gas separation unit is investigated. A comparison with experiments performed at TU Berlin shows a very good agreement with respect to integral values like permeate stream and pressure drop. Beside this the simulation allows a detailed insight in the flow field and species distribution. A second example shows the successful usage for desalination based on reverse-osmosis, where the osmotic pressure is calculated based on the chemical potential.