What emission factor should I use for pyrolysis oil made from plastic waste?
There is no IPCC default for pyrolysis oil from plastic, so build your own factor from a lab test: CO2 per kg equals the oil's carbon mass fraction times 44/12, and per litre you multiply by its density. All the carbon is fossil, so it counts in Scope 1. Do not borrow the furnace oil factor.
Why the furnace oil factor is the wrong shortcut
Pyrolysis oil from mixed plastic varies batch to batch with the feed and the reactor. It can be lighter than furnace oil, with a different carbon content, water content and density. Using 2.97 kg CO2 per litre, the IPCC 2006 based figure for furnace oil, would be a guess with no evidence behind it. The IPCC 2006 Guidelines, Volume 2, Chapter 1, allow a plant-specific factor where a fuel has no suitable default, provided it rests on measured properties.
What to ask the lab for
- Carbon content by mass, from an ultimate analysis such as ASTM D5291.
- Density at a stated temperature, in kg per litre.
- Net calorific value in MJ per kg, so you can check the factor per unit of energy.
- Water and ash content, since a wet sample lowers carbon per kg as delivered.
- Test samples from several deliveries, and repeat when the supplier or feed changes.
Fossil or biogenic
Carbon from plastic is fossil, so the CO2 goes in Scope 1 in full. If the supplier's feed also includes tyres, paper or other biomass, part of the carbon may be biogenic. Count it as fossil unless the supplier gives a measured biogenic share, for example from a radiocarbon test, and say which you did.
Checks before you rely on the oil
- The supplier should hold a valid consent to operate from its State Pollution Control Board for the pyrolysis unit; ask for a copy and check the conditions the board attached to it.
- Invoices should state litres or kg, so you have activity data to multiply by your factor.
- Keep the lab reports with the invoices for the same months; an auditor will want both.
- Methane and nitrous oxide from burning the oil are small; if you add them, name the proxy factor you used.
Worked example: building the factor from a lab report
- Lab results (illustrative): carbon 85% by mass, density 0.85 kg per litre
- CO2 per kg: 0.85 x 44/12 = 3.117 kg CO2 per kg
- CO2 per litre: 3.117 x 0.85 = 2.649 kg CO2 per litre
- Month's purchases: 20,000 litres
- Scope 1: 20,000 x 2.649 = 52,980 kg, about 53.0 t CO2
The lab values are illustrative assumptions, not defaults. The formula assumes all the carbon burns to CO2.
What Senseible does here
Senseible reads the litres or kg on pyrolysis oil invoices and calculates with published fuel factors from its IPCC 2006 table, so this line waits for a factor. Keep the lab report beside the invoices as the basis for the factor you calculate.
Sources: 2006 IPCC Guidelines, Volume 2 Energy, Chapters 1 and 2 (country or plant specific factors), GHG Protocol Corporate Standard
Last reviewed 2026-10-18.