WGC Emission Limits: Waste Gas Management and Treatment Systems in the Chemical Sector

Chemical manufacturing processes generate a plethora of waste gases, from volatile organic compounds (VOCs) and acidic gases to odour-causing emissions and hazardous pollutants. Following on from evolving legislation, businesses across the chemical, petrochemical and pharmaceutical sectors are under rising pressure as the demand for controlled emissions is heightened.

The latest WGC emission limits aim to improve the management of waste gases produced within the chemical sector. For many operators, the greatest challenge is understanding which pollutants need to be controlled and selecting the most effective treatment system for long-term industry compliance.

What are the WGC BAT Emission Limits?

The BAT Conclusions for Waste Gas Management and Treatment Systems, often referred to alongside WGC BREF (Best Available Techniques Reference Documents), form part of the Industrial Emissions Directive.

• The WGC BREF sets out best available techniques for managing and treating waste gases across industry.
• The BAT conclusions define the emission limits operators are expected to meet when applying those techniques.

The current framework must be adopted by EU member states into national law by 12^th December 2026.

These regulations focus on both channelled emissions, such as those released from stacks and vents, and diffuse emissions that stem from process equipment, storage tanks and transfer points. Originally published back in 2022, the four-year timeline is nearing an end, pushing businesses to review and source waste gas treatment before seeking rushed upgrades later down the line. The regulations aim to tackle several harmful pollutants with limitations, including:

• Volatile organic compounds (VOCs) (Total 3 – 20 mg C/Mn³)

• Halogenated VOCs (1–5 mg/Nm³)
• Hydrogen Chloride (HCI) (2–10 mg/Nm³)
• Hydrogen Fluoride (HF) (1–5 mg/Nm³)
• Other hazardous organic emissions

Why is Emissions Compliance becoming More Difficult for the Chemical Sector?

Across the chemical, petrochemical and pharmaceutical sectors, many sites already operate some form of extraction and abatement system. However, legacy systems are often designed around older permit limits, or even beyond this, and may not be capable of achieving the lower concentrations required under the new WGC rules. This is particularly prominent in facilities that handle products such as:

• Solvents
• Fine chemicals
• Petrochemicals
• Pharmaceutical intermediates
• Acids and alkalis
• Sulfur-containing compounds

Waste gas streams can also vary significantly throughout the day due to fluctuations in process temperature, production volume and chemical composition, making it difficult for a single industrial waste gas treatment system to maintain consistent performance. As a result, operators are increasingly looking for more robust and flexible treatment systems that can respond to variable contaminant levels without affecting production.

How Activated Carbon Systems offer VOC and Odour Removal

Within the WGC BREF, adsorption using activated carbon is recognised as a Best Available Technique (BAT) for treating VOCs, odours and harmful organic compounds from air or flue gas waste streams.

Activated carbon remains one of the most widely used advanced technologies on the market for waste gas treatment in the chemical sector and beyond. As gas passes through the activated carbon bed, organic contaminants are adsorbed onto its highly porous surface, allowing cleaner air to be released instead. For the chemical sector, activated carbon systems are most used in:

• Solvent storage and transfer areas
• Reactor vents
• Tank breathing lines
• Process extraction systems
• Chemical loading and unloading points

For many operators, activated carbon provides an efficient solution because it can handle a broad range of pollutants within a single system. Mobile carbon filters can also be installed quickly and expanded as future emission limits become more demanding.

Wet Scrubbers for Acidic and Water-Soluble Gases

If waste gas contains acidic or highly water-soluble compounds, wet scrubbing systems can be utilised. Outlined as another key BAT technique, a wet scrubber works by bringing the contaminated gas into contact with a liquid, usually water or a chemical solution, where the pollutants are absorbed or neutralised before the treated gas is released. Wet scrubbers are commonly used to remove:

• Hydrogen chloride (HCl)
• Sulfur dioxide (SO₂)
• Ammonia (NH₃)
• Chlorine
• Acid vapours

This makes them particularly suitable for chemical processes involving acids, alkalis, chlorination and inorganic chemicals. Packed bed scrubbers are one of the most common designs used in the chemical sector because they provide a large surface area for gas-liquid contact and can achieve high absorption.

However, scrubbers are less effective for controlling VOCs and hydrophobic organic compounds, particularly on their own. In these cases, they are often used alongside activated carbon to provide a comprehensive treatment solution.

Powdered Activated Carbon for High-Load and Complex Emissions

Some industrial processes produce waste gases with high concentrations of VOCs or complex contaminant mixtures that cannot be managed effectively by standard filtration alone. While thermal oxidisers can be used in these scenarios, they often come with high energy demand, complex infrastructure and increased operational cost. As a result, many operators are turning towards more flexible and cost-efficient alternatives.

Powdered activated carbon (PAC) offers a highly adaptable solution for targeting and treating both organic and inorganic contaminants, particularly within flue gas and stack emissions. When injected into a gas stream, PAC provides a large surface area that effectively captures:

• VOCs and hazardous organic compounds, like dioxins and furans
• Halogenated aromatic hydrocarbons
• Mercury and other heavy metals
• Persistent pollutants and trace contaminants

This approach is particularly suited for Energy-from-Waste (EfW) facilities, chemical and petrochemical processing, pharmaceutical manufacturing and industrial flue gas treatment systems.

Why Combined Treatment Systems are Becoming More Common

Because chemical waste gas streams often contain a mixture of contaminants, a single treatment method is not always enough, with many facilities now using a multi-stage approach to achieve WGC compliance. For example, a wet scrubber may remove acid gases before the remaining VOCs and odours pass through an activated carbon filter. Some arrangements may include:

• Source capture and extraction
• Primary scrubbing stage
• Carbon polishing stage
• Final stack monitoring

This multi-stage approach improves overall removal efficiency and gives operators greater confidence that emissions will remain within permit limits.

How Can Operators Monitor and Maintain Compliance?

Meeting WGC emission limits is not only about installing the correct equipment, but also requires operators to demonstrate long-term performance and commitment to eliminate harmful pollutants in the future. Environmental permits often require:

• Regular emissions monitoring
• Waste gas inventories
• Performance testing
• Routine inspection and maintenance
• Evidence that the treatment system is operating as designed

Monitoring is particularly important where PFAS compounds, VOCs, dust or hazardous pollutants are present. Emission limits may vary depending on the process and permit conditions, but facilities are expected to identify and control all relevant substances within the waste gas stream by the end of 2026. As legislation continues to evolve, businesses that review their systems early are likely to avoid costly upgrades and disruption to operations.

Engineering Carbon for Waste Streams

Not all waste gas streams are equal, and operators are dealing with a mixture of contaminants. This is where specialist engineering becomes essential, with carefully selected carbon media that can focus on goals, such as:

• Target specific molecules or compound groups
• Improve adsorption efficiency and lifespan
• Address challenging pollutants in flue gas and stack emissions
• Support compliance with multiple emission limits

How Puragen Helps Chemical Sectors Prepare for Future WGC Limits

At Puragen, our team of experts has extensive experience providing effective and sustainable solutions for Waste Gas Management. We work with multiple sectors to provide tailored, carbon-based solutions aligned with WGC BAT guidelines, from fine chemicals, pharma, industrial manufacturing, energy, municipal water and beyond. We offer:

• Selection of optimised activated carbon grades for specific applications
• Design of tailored adsorption systems for air, gas and flue streams
• Support with spent carbon handling, replacement and lifecycle management

With increasing pressure to meet 2026 compliance deadlines, early intervention allows operators to implement scalable, future-proof solutions that align with both regulatory requirements and operational efficiency. For further guidance about activated carbon services and gas treatment, please reach out to a member of our team today.