Introduction to Dividing-Wall Columns | AIChE

You are here

Introduction to Dividing-Wall Columns

March
2019

A dividing wall can be added within a distillation column to improve separation efficiency of three or more products.

Dividing-wall columns (DWCs) are a type of distillation column that can separate mixtures of several components into three or more high-purity streams (Figure 1). A DWC requires much less energy, capital investment, and plant space than conventional columns in series or parallel configurations. In fact, DWCs can have 20–30% lower capital cost requirements than conventional tower designs (1–5).

images

Figure 1. A standard dividing-wall column (DWC) has a wall that separates the column into two sections. The flow of vapor and liquid is shown with blue arrows and red arrows, respectively.

Conventional distillation columns are an integral part of the refining and chemical industries. Retrofitting existing columns with a dividing wall to improve separation efficiency is part of a larger push to intensify processes in these industries. Process intensification (PI) targets dramatic improvements in cost and energy efficiencies by rethinking traditional operation schemes. A DWC is one example of an intensified technology.

The concept of DWCs is well established, with much literature focusing on the simulation and control of these columns (1, 6, 7). Several publications have discussed the industrial applications of DWCs in different grassroots and retrofit applications (8, 9).

The technology is quite versatile, and no two DWC applications are exactly the same. Thus, it is difficult to develop a standard protocol for designing these columns. DWCs have been implemented in a variety of applications, such as gas plants, naphtha splitters, and reformate splitters, among others.

This article describes the three basic types of DWCs. An example demonstrates how adding a dividing wall can improve the purity of a side-cut stream without requiring the addition of a second column.

Would you like to access the complete CEP Article?

No problem. You just have to complete the following steps.

You have completed 0 of 2 steps.

  1. Log in

    You must be logged in to view this content. Log in now.

  2. AIChE Membership

    You must be an AIChE member to view this article. Join now.

Features

Copyright Permissions 

Would you like to reuse content from CEP Magazine? It’s easy to request permission to reuse content. Simply click here to connect instantly to licensing services, where you can choose from a list of options regarding how you would like to reuse the desired content and complete the transaction.