| Summary: | Membrane-based gas separation has attracted considerable interest over the past few years
because of its low energy consumption and cost-effective separation. Many studies have been
conducted related to amorphous silica membrane. This membrane has been reported to
perform well with respect to separating various gases including the Sasol Fischer Tropsch
gases Hydrogen, Methane and Carbon dioxide.
This study is devoted to the investigation of the performance of a commercially available
amorphous silica membrane for the separation of a typical Fischer Tropsch gas mixture.
For both single and binary permeation experiments performed, it was found that the membrane
permeation of the gases Hydrogen, Methane and Carbon dioxide is independent of the transmembrane
pressure.
As far as temperature is concerned, it was established that the permeation of the three gases is
inversely dependent on an increase in operating temperature. This was observed for both
single and binary permeation experiments.
In general, higher fluxes were achieved if the gases were fed directly onto the support (shell
side feed).
Selectivity towards Hydrogen was not significantly influenced by any of the operating
parameters investigated (temperature, trans-membrane pressure, membrane orientation).
The overall conclusions that were made based on the results obtained are that this membrane
can essentially be classified as a Knudsen-type membrane, since selectivity values are in the
region of Knudsen transport. The selectivity values are thus not large enough to qualify this
membrane as a successful gas separation membrane.
It was however, established that this membrane may perform more effectively if used for
pervaporation application purposes. === Thesis (M.Ing. (Chemical Engineering))--North-West University, Potchefstroom Campus, 2006.
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