Process Emissions vs Combustion Emissions: CBAM Classification

Key Takeaways

• Process emissions from chemical reactions constitute 65-70% of total steel production emissions and require direct measurement under CBAM
• Combustion emissions from fuel burning follow standardized emission factors but demand precise fuel consumption tracking
• Regulation (EU) 2023/956 mandates separate reporting methodologies for each emission category with distinct verification requirements
• Indian steel exporters must implement dual monitoring systems to capture both emission types accurately
• Non-compliance penalties can reach €50 per tonne of CO2 equivalent for unreported emissions

Understanding CBAM Emission Categories

The Carbon Border Adjustment Mechanism fundamentally distinguishes between two primary emission sources in steel manufacturing: process emissions and combustion emissions. This classification forms the backbone of carbon accounting under Regulation (EU) 2023/956 and determines the specific methodologies Indian steel exporters must employ for compliance.

Process emissions originate from chemical reactions inherent to steel production, particularly the reduction of iron ore using carbon-based reducing agents. These emissions are unavoidable byproducts of the metallurgical processes and cannot be eliminated without fundamental changes to production technology. In contrast, combustion emissions result from burning fossil fuels for energy generation, heating, or other operational requirements within the steel manufacturing facility.

The regulatory framework treats these emission categories differently due to their distinct characteristics and measurement methodologies. Process emissions typically require direct measurement or mass balance calculations, while combustion emissions can often be calculated using standardized emission factors combined with fuel consumption data. This differentiation has significant implications for monitoring system design and data collection protocols.

Process Emissions in Steel Manufacturing

Process emissions in steel production primarily occur during the reduction of iron ore in blast furnaces and basic oxygen furnaces. The chemical reaction Fe2O3 + 3CO → 2Fe + 3CO2 represents the fundamental process generating these emissions. For every tonne of steel produced through the blast furnace route, approximately 1.4 to 1.6 tonnes of CO2 are generated as process emissions.

These emissions are inherently linked to production volume and cannot be reduced without altering the fundamental chemistry of steelmaking. The carbon content of the reducing agents—coke, coal, and other carbonaceous materials—directly determines the magnitude of process emissions. Indian steel manufacturers using the blast furnace-basic oxygen furnace route typically generate process emissions ranging from 1,200 to 1,800 kg CO2 per tonne of crude steel.

Measurement methodologies for process emissions under CBAM require either continuous emissions monitoring systems (CEMS) or mass balance calculations based on carbon input and output streams. The mass balance approach involves tracking all carbon-containing inputs (coke, coal, limestone) and outputs (steel, slag, dust) to determine the carbon converted to CO2. This method demands precise measurement of material flows and carbon content analysis.

Electric arc furnace operations, prevalent among Indian secondary steel producers, generate significantly lower process emissions. The primary process emissions in EAF operations stem from the oxidation of carbon in scrap steel and any carbon-containing additives. These emissions typically range from 50 to 150 kg CO2 per tonne of steel, making EAF-based production substantially less carbon-intensive from a process emissions perspective.

Combustion Emissions Classification

Combustion emissions encompass all CO2 releases from burning fossil fuels within the steel manufacturing boundary. These emissions occur in various operational units including power generation, heating furnaces, coke ovens, and auxiliary equipment. Unlike process emissions, combustion emissions can be reduced through fuel switching, energy efficiency improvements, or renewable energy adoption.

The CBAM framework requires detailed tracking of fuel consumption across all combustion sources. Natural gas combustion generates approximately 2.03 kg CO2 per cubic meter, while coal combustion produces 2.42 kg CO2 per kilogram of coal burned. These standardized emission factors, when combined with accurate fuel consumption data, provide the basis for combustion emissions calculations.

Indian steel facilities must establish comprehensive fuel monitoring systems capturing consumption data for all fossil fuel types. This includes natural gas for heating and power generation, coal for steam production, diesel for mobile equipment, and any other hydrocarbon fuels used in operations. The monitoring system must differentiate between fuels used for different purposes to ensure accurate allocation of emissions to specific production processes.

Indirect combustion emissions from purchased electricity consumption also fall under CBAM scrutiny. Indian steel manufacturers must track electricity consumption and apply the appropriate grid emission factor for their regional electricity supply. The Central Electricity Authority of India publishes grid emission factors annually, with the current national average approximately 0.82 kg CO2 per kWh.

Measurement and Monitoring Requirements

CBAM compliance demands robust measurement and monitoring systems capable of accurately quantifying both emission categories. Process emissions monitoring requires either direct measurement through continuous emissions monitoring systems or calculation methods based on mass balance principles. Direct measurement involves installing CEMS at emission points to continuously monitor CO2 concentrations and flow rates.

Mass balance calculations for process emissions involve tracking all carbon inputs and outputs within the production system. This methodology requires accurate measurement of raw material consumption, including coke, coal, limestone, and other carbon-containing materials. The carbon content of these materials must be determined through regular sampling and analysis. Output streams including steel products, slag, and dust must also be quantified with their respective carbon contents.

Combustion emissions monitoring focuses on fuel consumption measurement and emission factor application. Flow meters, weighing systems, and volumetric measurements provide the foundation for fuel consumption data. The accuracy of these measurements directly impacts the reliability of combustion emissions calculations. Indian steel manufacturers must ensure measurement uncertainty remains within acceptable limits as specified in CBAM implementing regulations.

Data management systems must maintain separate records for process and combustion emissions, enabling independent verification of each category. The systems must capture temporal variations in emissions, production rates, and operational parameters to support detailed emissions reporting. Integration with existing plant control systems can enhance data accuracy and reduce manual data collection requirements.

2025-2026 Regulatory Impact

The transition from CBAM's reporting-only phase to the financial obligations phase in 2026 significantly amplifies the importance of accurate emission classification. During 2025, Indian steel exporters must demonstrate full compliance with emission monitoring and reporting requirements while preparing for certificate purchasing obligations beginning January 1, 2026.

The European Commission's technical guidance documents, expected for release in early 2025, will provide detailed specifications for emission measurement methodologies and verification procedures. These documents will clarify acceptable measurement uncertainties, data quality requirements, and verification protocols specific to process and combustion emissions in steel manufacturing.

Indian steel manufacturers must complete installation and commissioning of compliant monitoring systems by mid-2025 to ensure adequate operational data for 2026 certificate calculations. The lead time for CEMS installation and calibration typically ranges from 6 to 12 months, making immediate action essential for facilities lacking adequate monitoring infrastructure.

The financial impact of emission classification accuracy becomes substantial in 2026. With CBAM certificate prices expected to track EU ETS allowance prices, potentially reaching €80-100 per tonne CO2, measurement errors could result in significant financial exposure. A 1000-tonne monthly steel shipment with 10% measurement uncertainty could create financial risk of €160,000-200,000 per month.

Verification and Compliance Protocols

CBAM verification requirements establish distinct protocols for process and combustion emissions verification. Third-party verification bodies must possess specific competencies for each emission category, including understanding of steel production chemistry for process emissions and fuel combustion principles for combustion emissions.

Process emissions verification involves detailed review of mass balance calculations, raw material carbon content analysis, and production data reconciliation. Verifiers must examine the completeness of carbon input accounting, accuracy of material flow measurements, and appropriateness of carbon content determination methods. Site visits typically include inspection of sampling procedures, laboratory analysis capabilities, and data management systems.

Combustion emissions verification focuses on fuel consumption measurement accuracy, emission factor application, and calculation methodology review. Verifiers examine fuel delivery records, storage tank measurements, flow meter calibrations, and consumption allocation methods. The verification process must confirm that all combustion sources within the facility boundary are included in emissions calculations.

Indian steel exporters must engage accredited verification bodies with demonstrated competence in steel industry emissions verification. The verification process should commence well before the annual reporting deadline to allow time for addressing any identified deficiencies. Verification reports must explicitly address the accuracy and completeness of both process and combustion emissions quantification.

Implementation Strategy for Indian Steel Exporters

Successful CBAM compliance requires systematic implementation of monitoring systems addressing both emission categories. Indian steel manufacturers should conduct comprehensive emissions inventories identifying all process and combustion emission sources within their facility boundaries. This inventory forms the foundation for monitoring system design and implementation planning.

Process emissions monitoring implementation should prioritize the most significant emission sources, typically blast furnaces and basic oxygen furnaces for integrated steel plants. Mass balance approaches may offer cost-effective solutions for facilities where direct measurement installation faces technical or economic constraints. However, the chosen methodology must meet CBAM accuracy requirements and verification standards.

Combustion emissions monitoring implementation requires comprehensive fuel consumption tracking across all facility operations. Integration with existing energy management systems can leverage existing infrastructure while ensuring CBAM compliance. Separate metering for different fuel types and applications enables accurate emissions allocation and supports optimization efforts.

Training programs for facility personnel must address both emission categories, ensuring operators understand the distinct requirements and methodologies. Technical competency in emissions calculation, data management, and quality assurance procedures is essential for maintaining compliance and supporting verification activities.

Frequently Asked Questions

Q: Can process emissions be reduced through operational changes? A: Process emissions in steel manufacturing are largely determined by the chemical stoichiometry of iron ore reduction and cannot be significantly reduced without fundamental technology changes such as hydrogen-based direct reduction.

Q: How are emissions allocated between different steel products in a multi-product facility? A: CBAM requires allocation based on production mass or economic value. Process emissions are typically allocated based on steel production tonnage, while combustion emissions may be allocated based on energy consumption patterns.

Q: What happens if monitoring equipment fails during production? A: CBAM regulations require backup measurement methods or conservative estimation procedures during equipment failures. Facilities must maintain redundant monitoring capabilities or approved alternative calculation methods.

Q: Are emissions from waste gas utilization considered process or combustion emissions? A: Waste gas utilization for energy generation creates combustion emissions. However, the waste gas itself may originate from process emissions, requiring careful accounting to avoid double-counting.

Q: How frequently must emission factors be updated? A: Emission factors for combustion emissions should be updated annually or when fuel specifications change significantly. Process emission factors derived from mass balance calculations require updating whenever raw material compositions change substantially.