# How does an Ariyalur cement plant's mix of coal, pet coke and lignite change its CO2 per tonne of clinker?

Canonical: https://senseible.earth/answers/ariyalur-cement-plant-fuel-mix-co2

Calcination CO2 stays about the same, roughly half a tonne per tonne of clinker. Fuel CO2 depends on heat per tonne and the fuel's factor: IPCC defaults are about 94.6 kg CO2 per GJ for bituminous coal, 97.5 for pet coke and 101 for lignite.

## Steps

1. Heat per tonne of clinker, in GJ, from kiln fuel and output.
2. Share of heat from each fuel.
3. Fuel CO2 = heat × weighted factor.
4. Add calcination from clinker CaO and MgO.

## What lowers it

Alternative fuels such as biomass or plastic waste, a lower heat rate, and less clinker per tonne of cement.

## What Senseible does here

Senseible reads fuel invoices into a dated, fingerprinted record, so each figure shows the quantity, factor and document it came from.

- [CO2 per tonne of clinker](https://senseible.earth/answers/co2-per-tonne-of-clinker-calculation)
- [Pet coke emission factor](https://senseible.earth/answers/petcoke-emission-factor-india)
- [Lignite emission factor](https://senseible.earth/answers/lignite-emission-factor-india)

Sources: [2006 IPCC 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 2026-10-22.