# How does a Vapi paper mill work out boiler coal emissions per tonne of paper?

Canonical: https://senseible.earth/answers/vapi-paper-mill-coal-boiler-per-tonne

Multiply the coal burned by its emission factor, then divide by tonnes of paper made. Senseible's default for coal invoices is 2.42 kg CO2 per kg; a factor from your own coal's lab calorific value is more accurate.

## Steps

Tonnes of coal from purchase or consumption records.

Multiply by the factor, or by a lab gross calorific value if you have one.

Divide by tonnes of paper made.

## Better than a default

If you test the coal's calorific value, a factor from that test is more accurate than a default. Keep the lab reports with the invoices.

## Worked example: one day (illustrative quantities)

- Coal: 9,000 kg x 2.42 = 21,780 kg CO2
- Paper made: 50 tonnes
- Per tonne: 21,780 / 50 = 435.6 kg CO2

Quantities are illustrative; 2.42 kg CO2 per kg is the default Senseible applies to coal invoices.

## What Senseible does here

Senseible reads electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and diesel, LPG and gas invoices (IPCC 2006 defaults) into a dated, fingerprinted Scope 1 and 2 record for each site. Intensity per unit uses the activity count you enter, and estimates are labelled as estimates.

- [Paper mill per tonne](https://senseible.earth/answers/paper-mill-carbon-footprint-per-tonne)
- [Kraft paper per tonne](https://senseible.earth/answers/kraft-paper-carbon-footprint-per-tonne)
- [CO2 per tonne of steam](https://senseible.earth/answers/co2-per-tonne-of-steam)

Sources: [IPCC 2006 Guidelines, Volume 2 Energy](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html), [GHG Protocol Corporate Standard](https://ghgprotocol.org/corporate-standard)

Last reviewed 2026-10-21.