This DWC Innovations whitepaper presents a case study on revamping bottlenecked naphtha splitter columns with dividing wall column technology at a major South East Asia refinery. Two splitters in series fed light and heavy naphtha to the isomerization and CCR units — originally sized for 125 t/h, later debottlenecked to 185 t/h with structured packing and a side-cut that controlled benzene but lost C5 to the gasoline pool. When feed rose to 255 t/h, plot-space and capital constraints ruled out a new column, so the second splitter was retrofitted into a middle dividing wall column while the first stayed conventional — cutting overlap between the cuts.
Results delivered
38% increase in naphtha splitter capacity
Improved product specifications for top and bottom cuts
Higher revenue from increased feed to the isomerization and CCR units
No requirement for additional plot space
Revamp capex of $3 million versus $15 million for a new column
Debottleneck Distillation Columns with DWC Prime
Read the full case study — retrofitting a bottlenecked naphtha splitter into a middle dividing wall column for a 38% capacity gain at a fraction of new-column cost.
The revamp
Retrofitting the second splitter into a middle dividing wall column delivered a 38% capacity gain, better product specs, and higher feed to downstream units — for $3 million versus $15 million for a new column, with no extra plot space.
