A method for separating aromatic hydrocarbons from a feed stream. The
method includes flowing the feed stream through a first channel within a
first wafer assembly that may contain an underflow distribution weir.
Next, the feed stream is exposed to a first thin film polymer membrane. A
stream permeates through the first thin film polymer membrane, and the
permeate is produced from the first wafer assembly. The retentate is
directed via a redistribution tube to a second wafer assembly that may
contain an underflow distribution weir. This retentate is exposed to a
second thin film polymer membrane. A second permeate stream is created
that permeates through the second thin film polymer membrane. The second
permeate stream is flown into the permeate zone and ultimately produced
from the second wafer assembly. An apparatus for separating aromatic
components from a feed stream is also disclosed. In the preferred
embodiment, the apparatus includes a series of tandem wafer assemblies.
The wafer assemblies comprise a first wafer, second wafer and third
wafer. First and second membrane members are disposed within the wafer
assemblies.