Add Direct Emissions- Mass Balance Method

Overview

The Mass Balance Method in the kolum CBAM Supplier Portal is used to calculate direct emissions based on the carbon content of each material used or produced. This method is suitable for complex installations — for example, integrated steelworks — where it’s difficult to link emissions directly to individual input materials because the products (and wastes) themselves contain significant carbon quantities.

Using this method, the total amount of CO₂ relevant for each fuel, material, or product is calculated based on the carbon content in that material. Unlike the standard balance method, this approach does not distinguish between combustion and process emissions.

Carbon leaving the installation in output products is treated as non-emitted carbon and therefore recorded as negative activity data.

Minimum data requirements:

• Activity data (the amount of material used or produced)

• Carbon content

1. Monitoring Method

Select Mass Balance Method as your monitoring approach.

This determines that your emissions will be tracked based on carbon content, not on combustion or process differentiation.

Once selected, kolum will guide you through a sequence of data inputs to record all necessary parameters for CBAM reporting.

2. Fuel, Material or Product Used

Choose the fuel, raw material, or product involved in the process.

• You can select an existing material from the dropdown (e.g., Crude oil, Coke oven gas, Coking coal).

• Or add a new material if it’s not already listed.

Definition: A source stream is any material or product that either causes greenhouse gas emissions when used or made, or contains carbon that needs to be accounted for through mass balance.

3. Input or Output

Indicate whether the material is an Input or Output in the process.

• Input: A raw material, fuel, or product that enters the process and contributes carbon to it.

• Output: A product or by-product leaving the installation that still contains un-emitted carbon.

Choosing “Output” ensures that carbon leaving the installation is correctly deducted (negative activity data) to avoid double-counting emissions.

4. Measurement System Control

Question: “I have the measurement system under my control.”

Select Yes if you manage the measurement systems that collect your activity data directly (e.g., flow meters, weighing systems, or internal monitoring tools).

If you select No, the system provides alternative options for cases where measurements come from an external source.

If you select “No”

You’ll be asked to specify why your measurement system is not under your control:

• No own measurement system available – e.g., you rely on supplier data.

• Technically not feasible or would incur unreasonable costs – e.g., installing measurement devices is impractical.

• Outside measurement system more reliable – e.g., trade partner or third-party verified system.

Then, choose how you want to measure the amount used:

• Use amounts from invoices issued by a trade partner

• Readings from external measurement systems

kolum allows these exceptions only under specific circumstances, as CBAM prioritizes direct, verifiable measurements under supplier control.

5. Measuring the Amount Used

Choose how you want to measure the amount of material used:

• Continual metering at the process – Continuous on-site measurements.

• Aggregation of quantities across stock levels – Based on documented stock balances.

• Direct measurement not feasible / would incur unreasonable costs – Use estimated data if physical metering isn’t possible.

• Measurement over the entire reporting period not feasible – Use representative data over shorter time periods.

Then, enter the quantity of fuel, material, or product consumed, and select the appropriate unit:

• t (tonnes)

• 1000Nm³ (for gaseous materials)

This quantity forms the basis of the emission calculation in later steps.

6. Carbon Content Submission

Choose how you want to submit the carbon content:

• Direct value – You already know the carbon content (e.g., from a lab certificate).

• Calculated using the emission factor – kolum will derive the carbon content using emission factor data.

7. Determining the Carbon Content

If you choose Direct value, enter the carbon content manually.

If you select Calculated using emission factor, kolum will prompt you to specify how the carbon content was determined:

• By the use of values based on Laboratory Analysis (Preferred — provides the highest accuracy.)

• By the use of proxy data based on empirical correlations (Used when lab data isn’t available, and estimation is supported by technical evidence.)

• By the use of standard values (Fallback option using recognized references like IPCC or EU data.)

Enter the carbon content value once determined. Example: 2

8. Determining the Emission Factor

If the carbon content is calculated using the emission factor, you’ll be asked to specify how the emission factor is derived:

• By the use of values based on Laboratory Analysis

• By the use of proxy data based on empirical correlations

• By the use of standard values

Next, confirm if you have a better value than that of the EU or IPCC:

• Yes – Enter your specific emission factor.

• No – kolum will use the default standard values from EU or IPCC sources.

Then, provide:

• Emission factor (e.g., 73.3)

• Emission factor unit (tCO₂/t, tCO₂/TJ, or tCO₂/1000Nm³)

This defines how much CO₂ is emitted per unit of fuel or material consumed.

9. Determining the NCV (Net Calorific Value) Factor

Select how to determine the NCV factor — the energy content of the material:

• By the use of values based on Laboratory Analysis

• By the use of proxy data based on empirical correlations

• By the use of standard values

Then, enter the Net Calorific Value (NCV) in gigajoule per ton (GJ/t). Example: 2

If you don’t have a specific or more accurate NCV, kolum recommends using official values from the EU or IPCC.

10. Summary of Required Data Points

Data Point	Description	Source / Determination
Fuel, Material or Product	Material used or produced	Selected from dropdown or added manually
Input / Output	Defines carbon flow direction	User selection
Quantity	Amount consumed or produced	Measured or invoice-based
Carbon Content	Carbon share in the material	Lab, proxy, or standard
Emission Factor	CO₂ released per unit	Lab, proxy, or standard
NCV Factor	Energy content	Lab, proxy, or standard

kolum Tip

The Mass Balance Method is best suited for installations with interconnected material streams, such as refineries or integrated steel plants, where input and output materials contain measurable carbon. Ensure data sources are well-documented — including laboratory analyses, trade invoices, or standard references — to ensure CBAM compliance and transparency.