What does the Intergovernmental Panel on Climate Change guide give for CO2 per tonne of ethylene dichloride and vinyl chloride monomer, and why can I not add the two?
In the Intergovernmental Panel on Climate Change (IPCC) 2006 guide, the default balanced process emits 0.196 tonnes of carbon dioxide (CO2) a tonne of ethylene dichloride (EDC) or 0.294 a tonne of vinyl chloride monomer (VCM). The guide says the two are not additive.
Tier 1 CO2 factors (Table 3.17)
- Direct chlorination: combustion 0.191 a tonne of EDC and 0.286 a tonne of VCM; process vent negligible. Total 0.191 and 0.286 (the VCM total is printed as 0286, read as 0.286 from the combustion line above it).
- Oxychlorination: vent 0.0113 and 0.0166, combustion 0.191 and 0.286, total 0.202 and 0.302.
- Balanced process, the default: vent 0.0057 and 0.0083, combustion 0.191 and 0.286, total 0.196 and 0.294.
- The factors average European plants. One EDC plant fitted with a CO2 control device that reported zero was left out of the average.
Why they are not additive
The guide says the per-EDC and per-VCM factors both apply to the integrated EDC and VCM process. One is based on EDC production data and the other on VCM production data, so you use the one that matches the tonnes you have. Our reading: adding them counts the same plant twice. The same goes for the ethylene use factors in Table 3.18: 0.296 tonne of ethylene a tonne of EDC and 0.47 a tonne of VCM in the balanced process.
Only the CO2 pair is off a unit conversion. It implies 1.50 tonnes of EDC a tonne of VCM (0.294 / 0.196), while the molar masses of EDC and VCM give about 1.58. The ethylene pair, 1.59 (0.47 / 0.296), is close to that ratio. The guide does not say why the CO2 pair differs. Our reading is that each CO2 column is its own plant average.
What the table covers and leaves out
- Covered: CO2 from combustion of process waste gas and auxiliary fuel in the thermal incinerator, and from the process vent. The guide says the combustion factor does not include flares.
- Methane is negligible except for natural gas burnt as supplemental fuel: 0.0226 kg of methane a tonne of VCM, for integrated plants only, from 118.3 normal cubic metres of gas a tonne at 5 grams of methane a gigajoule.
- Our reading of scope: the table does not include making the ethylene or chlorine, or turning VCM into polyvinyl chloride (PVC). The guide names only process waste gas and auxiliary fuel in the incinerator; it does not say whether fuel for the EDC cracking furnaces is in the factor, though our page on vinyl chloride plants calls it the largest direct source. Keep cracker fuel as its own line unless the plant says otherwise. A resin buyer needs those from the resin supplier.
An integrated plant making 100,000 tonnes of VCM a year (example quantity)
- Balanced default: 100,000 x 0.294 = 29,400 tonnes of CO2
- Oxychlorination: 100,000 x 0.302 = 30,200 tonnes. Direct chlorination: 100,000 x 0.286 = 28,600 tonnes
- Wrong shortcut, adding the EDC and VCM factors: 100,000 x (0.196 + 0.294) = 49,000 tonnes, 67 percent too high
- Ethylene: 100,000 x 0.47 = 47,000 tonnes
- Methane: 100,000 x 0.0226 = 2,260 kg, 2.26 tonnes
Quantity is an example. The defaults are for national inventories and are based on European plants.
What Senseible does here
Senseible reads fuel invoices and electricity bills into dated, fingerprinted records, so your kilowatt-hours and litres are on file by date. It does not read a supplier's plant. Ask your resin supplier for its own plant figure and the year it covers.
- Vinyl chloride monomer plant emissions
- Dahej PVC supplier: carbon data for buyers
- PVC pipe carbon footprint per kg
- Resin factors for PP, HDPE and PVC
- Your MSME carbon number
Last reviewed 2026-11-06. Defaults are from the 2006 guidelines. A plant-specific figure replaces them.