The stripped ethanol from the beer column is concentrated in a distillation tower. Often two separate towers that perform rectification and stripping separately are used. The overhead product approaches the ethanol/water azeotropic concentration. Final dehydration beyond the azeotropic concentration is typically done using molecular sieves.
These towers have no special fouling tendencies. Depending on operating pressure, they may be equipped with either trays or structured packing. Koch-Glitsch has supplied the following trays for these columns: FLEXITRAY® valve trays, trays with VG-10 fixed valves, MINIVALVE® tray decks with VG-0 fixed valves, and SUPERFRAC® trays.
Structured packing is usually installed in the upper section of the rectifying column.
FLEXIPAC® HC® structured packing