Designing a Packed Dividing Wall Column for An Aromatics Processing Plant

This paper introduces a comprehensive design method assembled using facilities of a commercial software package that. Complemented by Excel programs containing own column dimensioning and well established cost estimation procedures, it enables proper assessment of industrial viability of a dividing wall column (DWC) equipped with corrugated sheet structured packings. The heart of the performance simulation tool is a detailed four-columns model that in conjunction with a simple, theoretically founded short-cut method providing reliable initial values for liquid and vapor splits, and a simple but effective objective function for design optimality indication allows determination of the adequate stage and reflux requirement of a DWC. The proposed dimensioning method enables a close approach in accuracy to that required at the stage of conceptual design for purposes of making a bid by an equipment manufacturer. Compared to a two-columns-in-series configuration, as employed in aromatics processing complex within a refinery, a DWC equipped with state of the art structured packing and auxiliary internals requires approximately 40 % less energy to deliver three fractions at required product specifications. This, accompanied by a saving of 45 % based on total annualized costs, indicates that implementing a DWC could lead to significant increase in profitability of aromatics processing plants.