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.
