Carbon Savings Calculator
Enter the reboiler duties you run today. Read back the CO₂e avoided, what it is worth, and how it measures against the whole refinery.
Carbon screening
The carbon case for a dividing wall column
Enter the reboiler duties you run today. Read back the CO₂e avoided, what it is worth, and how it measures against the whole refinery.
USD is the base — rate fixed at 1.Basis—
The refinery you are comparing against
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The columns you run today
Total today 25.0 MMkcal/h
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The saving
The sequence becomes one column
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The same carbon, in everyday terms
Notes, assumptions and sources
Carbon. Avoided CO₂e follows steam mass — tonnes per hour × operating hours × the steam carbon factor. Reboiler duty converts to steam through the latent heat set in the basis.
Money. The steam figure values the saving at the site’s internal steam transfer price. The fuel-gas figure prices the same heat as the fuel a boiler would otherwise have burned — heat saved ÷ boiler efficiency × fuel gas price. The two differ because a transfer price carries water treatment, distribution and capital recovery that raw fuel does not; quote whichever basis the client’s economics team uses. Prices are entered and shown in the currency chosen in the basis, and the arithmetic runs in US dollars, so switching currency re-expresses the same price rather than changing it.
Refinery totals. No Indian refiner publishes a verified refinery-by-refinery CO₂e figure — the majors disclose company-wide Scope 1 and 2 only. One exception sets the yardstick: HMEL Bathinda, whose Sustainability Report FY2023-24 gives 4.30 Mt Scope 1 against 12.6 MMT throughput; a single-refinery company, so the corporate disclosure is the refinery. Every other figure in the list comes from the Climate TRACE 2024 asset inventory, which computes throughput × an emission factor assigned by refinery archetype rather than measuring, and which flags its own refining data as low confidence; against HMEL’s disclosure it reads 16 % low. Treat every modelled figure as ±20 %. Reliance Jamnagar carries a further caveat: DTA and SEZ are lumped into a single asset and cannot be separated. Each refinery is shown as capacity × carbon intensity so the arithmetic stays visible — change either and the total follows, or type the total and the intensity follows. Published Indian refinery intensities run about 0.22 to 0.34 tonnes of CO₂e per tonne of crude, against a global volume-weighted average of 0.30 (Jing et al., Nature Climate Change 2020). For a refinery not listed, an audited total is always the figure to prefer; failing that use capacity × intensity, taking 0.22 for a simple refinery, 0.28 typical, 0.34 for deep conversion.
Everyday equivalents. 4.6 t CO₂e per car-year and 2.08 t per hectare of forest per year. The household figure follows the refinery you pick, because a home is not the same size everywhere: it is that country’s average household electricity multiplied by its 2024 grid carbon intensity (Our World in Data / Ember). India 1,005 kWh × 708 g = 0.71 t; China 2,180 × 555 = 1.21 t; Japan 4,749 × 483 = 2.29 t; Malaysia 4,456 × 604 = 2.69 t; South Korea 3,000 × 416 = 1.25 t; Taiwan 4,200 × 635 = 2.67 t; Singapore 4,200 × 499 = 2.10 t; Saudi Arabia 12,000 × 692 = 8.30 t; UAE 14,000 × 468 = 6.55 t; Kuwait 20,000 × 637 = 12.74 t; Oman 14,000 × 545 = 7.63 t. The household figures for India, China, Japan and Malaysia are the IEA’s; the others are derived from residential electricity per head and average household size and are round estimates. Indicative, for communication only.
About this tool A dividing wall column does in one shell what a conventional sequence needs two or three columns to do. Because the wall stops the middle-boiling component being remixed and re-separated, the reboiler duty for the same separation falls — typically by 25 to 40 per cent, with 30 per cent a fair screening figure. This tool turns that duty saving into the three numbers a revamp study actually has to report: tonnes of CO2e avoided per year, the money value of the steam or fuel gas no longer raised, and the size of the saving set against a whole refinery’s annual emissions. It is a screening tool, not a design. Enter the reboiler duties of the one to three columns you run today, choose the saving your basis supports, and read the answer back. Nothing is stored and nothing is sent anywhere — the arithmetic runs in your browser.What a dividing wall column saves
How the calculation works
How much CO2e does a dividing wall column save?
On a two-column sequence drawing 25.0 MMkcal/h of reboiler duty, a 30 per cent saving is about 16 tonnes per hour of MP steam, or roughly 31,500 tonnes of CO2e a year at 8,000 hours. Your own answer depends entirely on the duties you run and the steam grade each column uses — that is what the tool is for.
What emission factor is used for steam?
0.2515 tonnes of CO2e per tonne of steam. It is back-calculated from DWC Innovations’ own delivered projects, where the same factor holds across all three. Substitute your own site factor if you have one.
Can I price the saving in my own currency and units?
Yes — US dollars, Indian rupees, euros, pounds sterling, Saudi riyals, UAE dirhams, Singapore dollars, Chinese yuan, Japanese yen and Korean won, with duty in MMkcal/h, MMBtu/h, MW or GJ/h and steam in t/h or klb/h. Picking a refinery sets the currency and the units its engineers would normally use. Every price is editable.
Which refineries can I compare against?
Thirty-seven refineries across India, Asia and the Middle East, each shown as capacity × carbon intensity so the arithmetic stays visible. You can also type your own capacity, intensity or audited total. Sources and their uncertainty are set out in the notes above.