# Do anthracite, bone ash, and barium, potassium or strontium carbonate in a glass batch add carbon dioxide under the Intergovernmental Panel on Climate Change guide?

Canonical: https://senseible.earth/answers/ipcc-glass-batch-anthracite-and-minor-carbonates

Yes. The Intergovernmental Panel on Climate Change (IPCC) glass section names barium carbonate, bone ash, potassium carbonate and strontium carbonate as minor sources of carbon dioxide (CO2), and powdered anthracite or other organic material that burns in the melt. Table 2.1 prints no factor for them, so work out your own.

## What the guide lists

- Major sources: limestone, dolomite and soda ash.
- Minor sources: barium carbonate (BaCO3), bone ash, potassium carbonate (K2CO3) and strontium carbonate (SrCO3).
- Reducing agent: the guide says powdered anthracite coal or some other organic material may be added to create reducing conditions in the molten glass, and will combine with available oxygen in the melt to produce CO2.

## Which carbonates count

Carbonates mined as carbonate minerals count, as primary CO2 production. The guide says a carbonate produced through the carbonation of a hydroxide gives no net CO2 and should not be included. It also says the CO2 that stays dissolved in finished glass is relatively insignificant and can be ignored, so do not subtract it.

## A factor for each, from the formula

Table 2.1 lists only calcite, magnesite, dolomite, siderite, ankerite, rhodochrosite and soda ash. For the minor carbonates, divide the CO2 released by the carbonate's formula weight. With the atomic weights that reproduce the table (carbon 12.0107, oxygen 15.9994, so CO2 is 44.0095), this is my arithmetic, not an IPCC figure:

- Barium carbonate: formula weight 197.3359, so 44.0095 / 197.3359 = 0.2230 tonnes of CO2 per tonne.
- Potassium carbonate: 138.2055, so 0.3184.
- Strontium carbonate: 147.6289, so 0.2981.
- Check on the method: calcite is 44.0095 / 100.0869 = 0.43971, the table's own factor.

## Bone ash and anthracite

The guide writes bone ash as 3CaO2P2O5 + XCaCO3. Only the carbonate part releases CO2, so you need the supplier's carbonate share. For anthracite powder, each kilogram of carbon that burns fully gives 44.0095 / 12.0107 = 3.664 kilograms of CO2. Take the carbon share from the supplier's analysis. The guide gives no factor for it, so full conversion is my assumption.

## A month of extras for one furnace

- Barium carbonate: 0.8 tonnes x 0.2230 = 0.1784 tonnes of CO2
- Potassium carbonate: 0.5 tonnes x 0.3184 = 0.1592 tonnes
- Anthracite powder: 0.3 tonnes at 80% carbon = 0.24 tonnes of carbon x 3.664 = 0.8794 tonnes
- Sum: 0.1784 + 0.1592 + 0.8794 = 1.2170 tonnes, reported as 1.2

Quantities and the 80% carbon share are example numbers. Soda ash, limestone and dolomite go on their own lines, and furnace fuel is separate.

## What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records. It does not read batch sheets, so the carbonate and anthracite lines come from your own batch records, kept apart from the fuel lines.

- [IPCC glass factors and cullet ratios](https://senseible.earth/answers/ipcc-glass-default-factors-by-glass-type-and-cullet)
- [Firozabad glass batch carbonates](https://senseible.earth/answers/firozabad-glass-batch-carbonates-process-co2)
- [Frit and glaze carbon footprint](https://senseible.earth/answers/ceramic-frit-carbon-footprint-per-kg)
- [Which limestone uses release CO2](https://senseible.earth/answers/which-limestone-uses-release-carbon-dioxide)

Sources: [IPCC, 2006 Guidelines, Volume 3, Chapter 2: Mineral Industry Emissions](https://www.ipcc-nggip.iges.or.jp/public/2006gl/pdf/3_Volume3/V3_2_Ch2_Mineral_Industry.pdf)

Last reviewed 2026-11-06. Quotes and figures are from the 2006 IPCC Guidelines, Volume 3, Chapter 2. The 2019 Refinement was not checked for this page; check it if a buyer names it. The factors for barium, potassium and strontium carbonate are the page's own arithmetic from standard atomic weights.