Choice of method

There are two primary methodologies for estimating emissions from the use of carbonate(s) for these source categories. The Tier 1 method assumes that only limestone and dolomite are used as carbonate input in industry, and allows for the use of a default fraction of limestone versus dolomite consumed. Tier 2 is the same as Tier 1 except country specific information on the fraction of limestone versus dolomite consumed must be determined. The Tier 3 method is based on an analysis of all emissive uses of carbonates.

It is possible that Tier 3 could be used for some sub-categories, and a Tier 1 or 2 method used for other categories with limited data availability. Such a hybrid approach is consistent with good practice. The selection of method depends on national circumstances.

TIER 1 METHOD

The Tier 1 method is based on Equation 2.14.

Equation 2.14

Tier 1: Emissions based on mass of carbonates consumed CO2 Emissions = Mc • (0.85 EFls + 0.15 EFd)

Where:

CO2 Emissions = emissions of CO2 from other process uses of carbonates, tonnes Mc = mass of carbonate consumed, tonnes

EFis or EFd = emission factor for limestone or dolomite calcination, tonnes CO2/tonne carbonate (see Table 2.1)

It is suggested that inventory compilers ensure that data on carbonates reflect pure carbonates and not carbonate rock. If data are only available on carbonate rock, a default purity of 95 percent can be assumed. For clays a default carbonate content of 10 percent can be assumed4, if no other information is available.

Soda ash is primarily sodium carbonate, not limestone or dolomite. Therefore, the Tier 1 method for soda ash does not require the default fraction of 85%/15%. Emissions are estimated by multiplying the quantity of soda ash consumed on the national level by the default emission factor for sodium carbonate (see Table 2.1).

TIER 2 METHOD

Under Tier 2, the amount of CO2 emitted from the use of limestone and dolomite is estimated from a consideration of consumption and the stoichiometry of the chemical processes. Tier 2 uses a similar equation to Tier 1, but Tier 2 requires national data on the quantity of limestone and dolomite consumed in the country (Equation 2.15). It is not good practice to use a default for the allocation between these two primary carbonates.

Equation 2.15 Tier 2: Method for other process uses of carbonates

Where:

CO2 Emissions = emissions of CO2 from other process uses of carbonates, tonnes

Mls or Md = mass of limestone or dolomite respectively (consumption), tonnes. (Refer to Equation 2.14 above regarding purity.)

EFls or EFd = emission factor for limestone or dolomite calcination respectively, tonnes CO2/tonne carbonate (see Table 2.1)

TIER 3 METHOD

The Tier 3 methodology is similar to the approach outlined for cement above, but there is no need to correct for dust or other raw material inputs (Equation 2.16). As noted above, wherever this approach is used, it is important that all carbonate inputs are considered in the analysis.

4 EU-BREF (2005) reports a range of carbonate contents for relevant clays used in the ceramics industry ranging from 0 to over 30 percent.

Equation 2.16

Tier 3: Carbonate input approach for other process uses of carbonates

Where:

CO2 Emissions = emissions of CO2 from other process uses of carbonates, tonnes

Mj = mass of the carbonate i consumed, tonnes (Refer to Equation 2.14 above regarding purity.)

EFj = emission factor for the carbonate i, tonnes CO2/tonne carbonate (see Table 2.1)

Fj = fraction calcination achieved for the particular carbonate i, fraction. Where the fraction calcination achieved for the particular carbonate is not known it can be assumed that the fraction calcination is equal to 1.00.

i = one of the carbonate uses

Figure 2.4 Decision tree for estimation of CO2 emissions from other process uses of carbonates

Figure 2.4 Decision tree for estimation of CO2 emissions from other process uses of carbonates

Note:

1. See Volume 1 Chapter 4, Methodological Choice and Identification of Key Categories (noting Section 4.1.2 on limited resources), for discussion of key categories and use of decision trees.

Note:

1. See Volume 1 Chapter 4, Methodological Choice and Identification of Key Categories (noting Section 4.1.2 on limited resources), for discussion of key categories and use of decision trees.

Was this article helpful?

0 0
Guide to Alternative Fuels

Guide to Alternative Fuels

Your Alternative Fuel Solution for Saving Money, Reducing Oil Dependency, and Helping the Planet. Ethanol is an alternative to gasoline. The use of ethanol has been demonstrated to reduce greenhouse emissions slightly as compared to gasoline. Through this ebook, you are going to learn what you will need to know why choosing an alternative fuel may benefit you and your future.

Get My Free Ebook


Post a comment