# How does a Tiruppur dyeing unit count emissions from a firewood boiler?

Canonical: https://senseible.earth/answers/tiruppur-dyeing-unit-firewood-boiler-emissions

CO2 from burning wood is biogenic: report it separately, outside the scopes. Methane and nitrous oxide from the burning still count in Scope 1. With IPCC defaults, a tonne of firewood gives about 1.75 t of biogenic CO2 and about 0.03 t CO2e of Scope 1 gases.

## The defaults used

- Net calorific value of wood: 15.6 GJ per tonne (IPCC 2006 Vol 2, Table 1.2).
- CO2: 112,000 kg per TJ, reported as biogenic.
- CH4: 30 kg per TJ and N2O: 4 kg per TJ (Table 2.3).
- GWP: 27.0 for non-fossil methane and 273 for N2O (IPCC AR6).

## Evidence

Keep purchase invoices by weight. If the wood is bought by volume or by the cart, record the conversion you used and its source.

## Worked example: 10 tonnes of firewood (IPCC defaults)

- Energy: 10 t x 15.6 GJ = 156 GJ = 0.156 TJ
- Biogenic CO2: 0.156 x 112,000 = 17,472 kg, reported outside the scopes
- CH4: 0.156 x 30 = 4.68 kg x 27.0 = 126.4 kg CO2e
- N2O: 0.156 x 4 = 0.624 kg x 273 = 170.4 kg CO2e
- Scope 1: 126.4 + 170.4 = 296.8 kg CO2e

The fuel quantity is illustrative; the factors are IPCC defaults.

## 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.

- [Firewood by quintal](https://senseible.earth/answers/firewood-by-quintal-emissions)
- [Biomass in a boiler](https://senseible.earth/answers/biomass-or-waste-fuel-in-boiler-scope-1)
- [Biomass supplier evidence](https://senseible.earth/answers/biomass-fuel-supplier-evidence)

Sources: [IPCC 2006 Guidelines, Volume 2 Energy](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html), [IPCC AR6 Working Group I, Chapter 7 (GWP values)](https://www.ipcc.ch/report/ar6/wg1/), [GHG Protocol Corporate Standard](https://ghgprotocol.org/corporate-standard)

Last reviewed 2026-10-21.