Synthetic ethanol
Synthetic ethanol is primarily produced by catalytic hydration of ethylene.  The catalyst and several byproducts are present in the crude ethanol product. Distillation is used to recover the ethanol.

Topping column and rectifying column
The crude ethanol product from the reaction step is concentrated and purified in two distillation columns.
  • The first tower, commonly called the topping column, removes lights. 
  • The second tower, the rectifying column, removes intermediate components and water.


Trays are commonly used in these towers. The service is clean. Depending on required capacity and flexibility, the following tray products may be used:  FLEXITRAY® valve trays, trays with
VG-10 fixed valves or MINIVALVE® tray decks with VG-0 fixed valves, or SUPERFRAC® trays.