Dual Dividing Wall Column Technology
Produce more products from the same column. Dual DWC Prime™ handles separations a single dividing wall cannot, delivering extra product cuts, higher-value streams and more capacity from one shell.
Dual DWC Prime · DDWC
What Is a Dual Dividing Wall Column?
Dual DWC Prime (DDWC Prime) extends our process-intensification portfolio a step further than a standard single-wall dividing wall column. Instead of merging two columns into one shell, DDWC Prime merges three or more conventional columns into a single shell, delivering four or more high-purity products from that one shell. Because it consolidates more separation duty into a single piece of equipment, DDWC Prime reaches an even higher thermodynamic efficiency than a single-wall DWC.
Dual DWC vs Conventional Distillation TrainsView the comparison
| 3-column sequence | Dual DWC Prime | |
|---|---|---|
| Distillation columns | 3 | 1 |
| Products | 4 (A, B, C, D) | Same 4 products from one shell |
| Total equipment items | 18 (pumps, condensers, reboilers and drums) | 8 |
| Plot space | Baseline | About 60% less |
| CAPEX | Baseline | About 50% lower |
| OPEX and energy | Baseline | About 50% lower |
Is it right for you?
When Does a Dual DWC Make Sense?
Some separations outgrow a single dividing wall. They need several columns, multiple side draws or extra recycle streams, and they consume a lot of energy.
A Dual DWC Prime™ column can often do the same work inside one shell, as a new column or a retrofit of an existing one.
Not sure what is limiting your column? Start with distillation troubleshooting, or compare with a single-wall dividing wall column.
- You need more products from one feed than a single-wall DWC can deliver
- A multi-column train or a column with several side draws does the job today
- An existing deisohexanizer in an isomerization unit should add a high-value C6 cut
- A naphtha splitter needs sharper light, medium and heavy cuts
- Lube base oil units need several grades from one column
- The unit is capacity-constrained and has no plot space for new columns
Why it matters
Why Refiners Choose Dual DWC Prime
- More products from the same feedRecover high-value products that would otherwise need extra equipment or be blended into lower-value streams.
- More throughput from existing assetsIncrease capacity without building additional columns.
- Lower capital costReplace a complex column train with one integrated separation, on a smaller plot.
- Lower energy useReduce remixing losses and eliminate unnecessary fractionation steps.
Applications
Applications of Dual DWC Prime
Dual DWC Prime is used where conventional columns or single-wall DWCs cannot economically deliver the required number of high-purity product streams. Below are DDWC Prime projects DWC Innovations has executed.
CPCL Chennai
3-Cut DIH → 4-Cut DDWC Prime
Unlock high-value C6 products from existing isomerization units. DWC Prime upgrades a three-cut DIH into a four-cut system producing valuable C6 products — boosting feed capacity, preserving RON, cutting energy use, adding new revenue, and delivering a fast 2–12-month payback.
BPCL Mumbai
LOBS Unit Revamp with Multi-Cut Separation
As part of a LOBS unit revamp, a new DDWC Prime column produced five lubricating-oil grades in a single shell, improving product recovery, cutting energy use, and eliminating the need for three separate columns — reducing plot space and simplifying operations.
MRPL Mangalore
Naphtha Splitter
Naphtha splitter was upgraded to a Dual DWC Prime column, delivering sharper three-cut separation, higher-purity light, medium and heavy naphtha streams, enhanced operational flexibility and stable control — all achieved with no increase in reboiler duty and minimal changes to existing equipment.
People buy products, not internals
What Products Can a Dual DWC Create?
Naphtha splitter
Isomerization unit (DIH)
Lube base oil unit
See these projects in our DWC case studies.
Proven in the field
Commercially Proven Dual DWC Technology
Commercial dual DWCs delivered
BPCL Mumbai, MRPL and CPCL, plus two dual-wall DWCs at a chemical complex in India.
World’s first multi-column DWC network
Four DWC Prime columns, two of them dual DWCs, now do the work of a seven-column separation train.
Press releases
Commissioned Around the World
Press Release
Successful Revamp of Naphtha Splitter Column to Dual DWC at MRPL, India
July 9, 2026
Read release →
How it works
Several walls, one shell
From the outside, a dual dividing wall column looks like an ordinary dividing wall column. Inside, it carries more than one partition — sometimes overlapping, at a single elevation or at several — so one shell does the work of a whole column train.
- Walls placed where the separation needs themMultiple partitions at one elevation or several, sized to the duty.
- Simple liquid and vapour splitsThe layout keeps the internal splits easy to set and control — the key to building and running it.
- Robust and flexible in operationStable and straightforward to run despite the extra separation it performs.
Questions & Answers
Dual and Multiple Dividing Wall Columns, Explained
Beyond the dual layout, DWC Prime also engineers multiple dividing wall column configurations — placing more than one dividing wall within a single shell to replace several conventional towers with one column. Whether a dual or a multiple dividing wall column best fits the separation, the objective is the same: fewer vessels, a smaller plot footprint, and lower capital and energy cost.
Can’t find your answer? Ask our engineers →
What is a dual dividing wall column (dual DWC)?
It’s one column doing the work of three or more. Where a standard DWC uses a single internal wall to split a feed into three products, a dual DWC (DDWC Prime) uses more than one wall to deliver four or more high-purity cuts from the same shell — at even higher thermodynamic efficiency.
How is a dual DWC different from a standard single-wall DWC?
Scale. A single-wall DWC combines two columns and makes three products; a dual DWC combines three or more and makes four or more, all in one vessel. Packing that much separation into a single shell is what lifts efficiency beyond a single-wall DWC — and it’s why dual DWCs are used mainly on large, multi-product duties.
Has anyone actually built a commercial dual DWC?
Yes — and to date, DWC Innovations is the only company with commercial experience in dual dividing wall columns. It has delivered five commercial dual DWCs: the world’s first commercial dual DWC at BPCL Mumbai, units at MRPL and CPCL, and two dual-wall DWCs at a chemical complex in India.
Why does DWC Innovations’ commercial dual-DWC experience matter?
Dual DWCs are far more complex than single-wall columns, and the gap between a paper design and a stable, on-spec commercial unit is where most attempts fall short. DWC Innovations has closed that gap in the field across five commercial dual DWCs — so you are working with the only proven commercial track record for this technology, not a first-of-a-kind experiment.
What can a dual DWC do that a single-wall DWC cannot?
A dual DWC handles multi-cut separations a single-wall DWC cannot — for example upgrading a 3-cut deisohexanizer to a 4-cut DDWC, multi-cut LOBS (lube oil base stock) unit revamps, and complex naphtha splitters — with a lower footprint and capital cost than the equivalent train of separate columns.
Which applications suit a dual DWC best?
The sweet spot is any separation that would otherwise take a train of columns to hit several on-spec products — for example a 3-cut DIH upgraded to a 4-cut unit, multi-cut LOBS revamps, and naphtha splitters. If you need multiple high-purity cuts but want to avoid the footprint, cost and energy of separate columns, it fits.
Can a dual DWC produce specialty or very high-purity products?
Yes. At CPCL, DWC Innovations commissioned a dual dividing-wall deisohexanizer that produces pharma-grade hexane — demonstrating that a dual DWC can meet demanding, high-value purity specifications in commercial operation.
Are dual DWCs difficult to operate given the added internal complexity?
No — operability is engineered in from the start. More walls do add internal complexity, but the layout is designed for stable, predictable behaviour, and every unit ships with a control scheme validated in dynamic simulation — so it runs as steadily as a conventional column across its full range.
What does DWC Innovations deliver on a dual DWC project?
The full scope — feasibility and process design, simulation and modelling, basic/feed and detailed engineering, locally manufactured internals, and complete project management through commissioning — backed by the only commercial dual-DWC track record in the industry.
Can an existing column be converted into a Dual DWC?
Yes. The MRPL naphtha splitter and the CPCL deisohexanizer were both existing columns converted to Dual DWC Prime, avoiding new columns and additional plot space.
What is the difference between a Dual DWC and a multi-wall DWC?
A dual DWC uses two dividing walls in one shell. A multi-wall DWC adds further partitions, configured for even more complex separations.
Could your column produce more than it does today?
Send us your separation challenge. We’ll evaluate whether a Dual DWC Prime retrofit can add capacity, create additional product cuts or reduce energy use.
