IPCC methodology for general carbonate calcination - tier 3
This methodology represents carbon dioxide (CO2) emissions associated with the calcination of carbonate minerals. The data and calculation methodology is sourced from the IPCC, as published in Volume 3, Chapter 2 - Mineral Industry Emissions of their 2006 IPCC Guidelines for National Greenhouse Gas Inventories. This methodology represents the IPCC tier 3 approach.
Limestone (CaCO3) and dolomite (CaMg(CO3)2) are basic raw materials having commercial applications in a number of industries. The heating of carbonate minerals to high temperatures ('calcining') produces metallic oxides as well as CO2 emissions. This methodology calculates CO2 emissions from the general consumption (through calcination) of carbonate minerals.
The methodology represents a mass-balance approach which considers the quantities of carbon (C) which enter the calcination process from all carbonate inputs and attributes any C which is unaccounted for on completion of the calcination process to CO2 emissions. The total quantity of each carbonate input fully calcined (and therefore emitted as CO2) is determined on the basis of the input quantity (i.e. mass) and the fraction calcination achieved (i.e. a decimal fraction, 0-1). This calcined quantity in then converted into it's corresponding CO2 quantity on the basis of conversion factors which represent the stoichiometry of the chemical processes, i.e. the known molecular mass ratio of the reactant carbonate material and the product CO2.
Carbonate inputs of calcite (or it's polymorph, aragonite), magnesite, dolomite, siderite, ankerite, rhodochrosite, and soda ash can be itemised as part of any calculation.
CO2 conversion factors (stoichiometric ratios) for all carbonate types are sourced from the IPCC and can be found here.
Activity data required
Greenhouse gas emissions are directly proportionate to the quantity (i.e. mass) of carbonates consumed. In addition, the fraction calcination achieved for each individual carbonate input can be specified (100% calcination is assumed otherwise).
Calculation and results
CO2 emissions are calculated by multiplying each carbonate input by it's respective calcination fraction and CO2 conversion factor (stoichiometric ratio).
This emissions calculated by this methodology represent those attributable to all specified quantities of carbonate calcined.
Several other IPCC methodologies are available which represent carbonate calcination. These include the IPCC tier 1 and tier 2 methodologies which correspond to this methodology, as well as methodologies specific to soda ash consumption, as well as glass and cement production.