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.
38%Splitter capacity gain
$3MRevamp capex vs $15M new
255 t/hFeed rate handled
0Extra plot space needed
Case study · South East Asia refinery
Results delivered
✓
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.
