(540g) A CFD Study on the Impact of Convective Flow Characteristics and Species Distribution on the Performance of Full-Scale Membrane Reactors

Membrane reactors are widely used within the industry to
selectively separate particles or species from a stream. Well-known examples
are the filtration of dust particles from flue gas or reverse-osmosis for
producing drinking water from seawater or other pharmaceutical related
separations. The main benefit of this reactor type is the modular structure and
the low energy consumption compared to other separation methods.

At AIChE
Spring Meeting 2015 an approach to simulate membrane processes by using the commercially
available CFD code STAR-CCM+ was presented. The results showed very good
agreement with experimental results and had the outcome that the performance
and efficiency of a membrane reactors is not only a function of the molecular functionality
of the membrane itself but also of the flow characteristics and species
distribution in the reactor.

Based on this work the separation
process in a full-scale multi-tubular membrane module consisting of more than
300 tubes like shown in the picture above is investigated. Two different
approaches are compared: The first one uses a 1D-3D coupled approach that
neglects radial profiles in the retentate side tubes
while the permeate side gets spatially resolved. The second method uses
advanced meshing technique to allow an efficient fully spatially resolved CFD
simulation of the whole reactor. The results reveal the limits of one
dimensional approaches and show how numerical simulation can help do develop
more efficient reactors by doing slight design changes.