Petrochemical naphtha (PCN) is an increasingly valuable feedstock for ethylene crackers, but stringent carbon disulfide (CS2) limits are hard to meet — CS2 irreversibly poisons hydrotreating and cracking catalysts. Common removal routes (hydrotreating, physical adsorption, distillation) each trade off capex, opex, and achievable purity. This whitepaper examines a South East Asia refinery whose naphtha splitter and depentanizer train sent CS2-laden naphtha to the gasoline pool. Rather than adding a new column or converting to a costly side-cut design, the facility revamped its depentanizer into a dividing wall column, producing three high-purity cuts at once.
<1 ppmCS2 specification met
90+ wt%iC5 recovery
3High-purity cuts
1Revamped DWC column
Case study · South East Asia refinery
Results delivered
✓
The revamp
Revamping the depentanizer into a DWC produced three high-purity cuts at once — an iC5-rich overhead over 90 wt% for premium gasoline, an nC5-rich side draw carrying most of the CS2, and a PCN bottoms stream meeting sub-1 ppm — while debottlenecking the hydrotreater and adding revenue, with no new column.