GT-DWC – Dividing Wall Column Design Saves Costs and Energy
Sulzer GTC Technology’s process equipment technology offerings can include the dividing wall column (DWC), which separates a multi-component feed into three or more purified streams within a single tower, thereby eliminating the need for a second column. This design saves capital and energy costs normally invested in a separation unit.
The DWC design uses a vertical wall to divide the middle of the column into two sections. The feed is sent to one side of the column called the pre-fractionation section. There the light components travel up the column where they are purified while the heavy components travel down the column. The liquid flow from the column’s top and the vapor flow from the bottom are routed to their respective sides of the dividing wall.
From the opposite side of the wall, the side product is removed from the area where the middle boiling components are most concentrated. This arrangement is capable of producing a much purer middle product than a conventional side draw column of the same duty, and at a higher flow rate. And for the same product specifications, GTC-DWC requires substantially lower capital and operating cost than a conventional two-column system.
The technology is especially suited for removing a heartcut from a multi-component mixture, where the alternative is a series of fractionating towers.