Executive Order (EU) 2022/2427 marks a step toward more stringent, technically-based emission control in the chemical industry, with modern air purification systems and integrated monitoring at its core.
With the Implementing Decision (EU) 2022/2427, the European Commission established the BAT conclusions for common systems for common treatment and management of waste gases in the chemical sector. This decree was issued pursuant to Directive 2010/75/EU (Industrial Emissions Directive – IED).
BAT conclusions are now the reference framework for permitting. Competent authorities must base emission limit values on the performance achievable with Best Available Techniques (BAT). This means that industries must optimize their waste gas treatment systems to effectively reduce air pollutant emissions.
For operators, this means: demonstrable control of all relevant emissions to air.
What does the decision include?
The decree contains a comprehensive set of BAT conclusions for systems used in the chemical industry to manage and treat waste gases. The scope specifically addresses activities under Annex I items 4.1 to 4.6 of the IED, or the most common production processes of the chemical sector.
The BAT conclusions address, among other things:
- Environmental Management Systems (EMS) that help organizations identify, monitor and control their emissions.
- Management of guided as well as fugitive emissions, including systems for monitoring and preventive measures against volatile organic compounds (VOCs).
- Technical measures and process optimizations to minimize emissions to air.
- Additional techniques specific to sectors such as polymer and PVC production.
What does this mean practically for chemical companies?
Integrated emissions management
The new BAT conclusions shift the focus from individual air treatment plants to an integrated waste gas management system. The new BAT conclusions no longer assess only individual treatment plants, but the entire emission management system.
This includes:
- Source measures
- Closed systems and vapor return
- Directed emissions through chimneys
- Fugitive emissions
- Monitoring and maintenance strategies
- Management of anomalous operating conditions (OTNOC).
Recommendation:
Conduct a comprehensive emissions inventory for your entire site. Systematically map all potential emission sources and link them to control measures and measurement strategies.
Controlling fugitive emissions
The BAT conclusions place an emphatic focus on diffuse emissions, especially of volatile organic compounds (VOCs). A structured approach is required.
Operators are expected to:
- Inventory components (valves, pumps, flanges, compressors)
- Implement a structured LDAR (Leak Detection And Repair) program.
- Record frequencies of measurements
- Perform repairs within established deadlines
- Documenting and evaluating results
Companies that manage fugitive emissions only reactively are at increased risk during permit review.
Recommendation:
Integrate LDAR into your maintenance management system. Set KPIs for leak frequency, repair time and emission reduction. An effective program not only reduces emissions but also reduces product loss and safety risks.
Monitoring and data quality become critical
The BAT conclusions place a strong emphasis on representative and reliable monitoring. This may include:
- Continuous emission measurements (where technically feasible)
- Periodic measurements according to applicable standards
- Mass balances for VOCs.
- Indicative parameters (e.g., TOC, flow rate, temperature)
Regulators expect measurement data to be not only available, but also methodologically sound and reproducible.
Recommendation:
Evaluate whether your current measurement strategy meets technical and legal robustness.
- Is the measurement site representative?
- Are calibrations and uncertainties documented?
- Are measurement frequencies determined risk-based?
Insufficiently substantiated monitoring is one of the biggest compliance risks.
Gas scrubbers as core technology within BAT
Within many chemical processes, gas scrubbers (scrubbers) remain an essential technique for removing acidic or basic components, ammonia, inorganic vapors and certain VOC fractions.
Gas scrubbers, however, must meet higher requirements than before:
- Optimal liquid-to-gas ratio (L/G).
- Uniform gas distribution
- Control of pH and conductivity
- Restriction of drip-feed (demisters).
- Continuous process monitoring
Properly designed and correctly sized gas scrubbers, can help achieve BAT performance levels. Particularly in applications such as:
- NH₃-removal
- HCl or SO₂ absorption
- Neutralization of process vapors
- Treatment of oxidizable components
Recommendation:
Evaluate existing gas scrubbers for load, process parameters and maintenance condition. In many cases, optimization of an existing plant can yield significant emission reductions without a complete replacement.
Monitoring and process control
A technically well-designed plant is not sufficient without demonstrable monitoring. The BAT conclusions call for:
- Representative emission measurements
- Substantiated mass balances
- Documentation of maintenance and calibration
- Evaluation of anomalous operating conditions
For gas scrubbers, this includes:
- Continuous pH recording
- Control of circulation flow rate
- Periodic checking of spray images
- Monitoring of salt accumulation and scaling
Installations that are technically adequate but inadequately monitored may still be assessed as non-compliant.
Management of OTNOC situations.
Emissions during startup, shutdown or outages (Other Than Normal Operating Conditions – OTNOC) are given explicit attention.
Operators must:
- Identify possible anomalous scenarios
- Analyzing emission effects
- Implementing mitigation measures
- Formalize procedures and registrations
In practice, this means:
- Sizing for peak load
- Prevention of bypass situations
- Rapid stabilization of operational parameters of the air handling system
- Clear emergency procedures
An integrated design, where gas scrubbers are combined with activated carbon, for example, provides additional security under varying process conditions.
Recommendation:
Develop a formal OTNOC management plan that defines technical, operational and organizational measures. This will prevent discussions during inspections and permit reviews.
Technical implications for off-gas treatment
In practice, compliance often means that plants must operate closer to their optimal operating conditions. This can include:
- Optimization of scrubber parameters (pH, L/G ratio, residence time)
- Temperature and oxygen control during thermal or catalytic oxidation
- Combination of multiple techniques to capture peak emissions
In addition, it must be demonstrated that the chosen technique is actually BAT within the specific context of your installation.
Recommendation:
Conduct a technical gap analysis comparing current emission levels against BAT-AEL ranges. Identify margins and vulnerabilities before tightening permit requirements.
Environmental management system as a foundation
The BAT conclusions expect a structured environmental management system that systematically identifies emission risks and ensures continuous improvement.
This includes:
- Clear responsibilities
- Document Management
- Internal audits
- Periodic evaluation of emissions performance
- Executive involvement
A certificate alone is not enough; effectiveness must be demonstrable.
Strategic preparation for permit review
Permits must be reviewed within four years of publication of the BAT conclusions. That means companies must prepare now.
A proactive approach includes:
- Internal BAT gap analysis
- Technical evaluation of existing air handling systems
- Economic justification for any deviations
- Dialogue with the competent authorities
Conclusion
The BAT conclusions under Executive Order (EU) 2022/2427 mark a further professionalization of emission management in the chemical sector. For companies, this means a clear strengthening of expectations around process management and emission reduction:
- Source reduction
- Operational control
- Optimization of existing treatment technologies
- Structural control of fugitive emissions
- Monitoring provided
- Strategic permit management
For companies using this approach, it offers not only certainty toward regulators, but also operational benefits: reduced product losses, higher process stability and lower long-term environmental costs.
Properly designed and properly maintained gas scrubbers are often a crucial building block within a BAT-compliant emission control system in this regard.
