Articles

Dividing wall distillation columns are now widely accepted in the industry. The existing naphtha complex became a bottleneck in the refinery. The naphtha complex consisted of hydrotreating, naphtha splitters, Isomerization and CCR units. Full range naphtha from crude distillation unit is stabilized in naphtha stabilizer then goes as feed to naphtha splitter. Light naphtha (C5/C6) is feed to Isomerization unit, bottoms C7 is the feed to CCR unit. A C6 cut is drawn as side cut to avoid benzene and precursors in the CCR feed.

Space constraints and strict product requirements led to the dividing wall distillation technology as the most effective option for revamp. Besides energy optimization, DWC technology provided a capacity increase of more than 40% over the use of high capacity internals.

Reprinted from PTQ Q1 2020.

This article provides an introduction to Dividing wall columns (DWCs). These distillation columns can separate mixtures of several components into three or more high-purity streams. 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.

Conventional distillation columns are an integral part of the refining and chemical industries. Introduction of dividing wall columns for revamp of existing columns 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. Read more..