What is a dividing wall column and what are its advantages and design challenges?

A dividing wall column (DWC) separates three or more components in a single shell using a vertical partition that creates a prefractionator section. Advantages: 30% energy savings, 30% capital cost reduction, smaller footprint compared to conventional two-column sequence. Challenges: more complex design requiring vapor/liquid split ratios, limited flexibility for feed composition changes, difficult to retrofit, control complexity with fewer manipulated variables, and proprietary internals. Best suited for close-boiling ternary mixtures.