Pet Food and Category 3 Animal By-Products Processing

Air emissions in Category 3 animal by-products processing plants

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category 3 animal by-products processing

Kibble and Category 3 animal by-products processing industry

Pet food processing plants and Category 3 animal by-products processing facilities generate complex air emissions during cooking, drying and raw material handling.
These emissions often contain ammonia, VOCs, odorous sulfur compounds, aerosols and organic particulate matter.
Effective treatment requires industrial air pollution control systems designed for process emissions, not standard ventilation or HVAC solutions.
Pet food plants operate with variable production conditions, high humidity and intermittent odour peaks, making process-driven design essential for reliable odour control.
In Europe, many pet food ingredients are produced from Category 3 animal by-products (ABP Cat.3) as defined by Regulation (EC) No 1069/2009.

In the European Union, facilities processing Category 3 animal by-products (ABP Cat.3) fall under the Industrial Emissions Directive (IED).
Air pollution control systems must therefore be designed in line with the BAT Conclusions for the Slaughterhouses and Animal By-Products Industries (Commission Implementing Decision (EU) 2023/2749), particularly regarding odour management, ammonia emissions and treatment of process exhaust air.

Emission Sources in Pet Food and ABP Processing Plants

Air emissions in pet food facilities originate from multiple production stages.

Typical emission sources include:

  • Rendering cookers and digesters
  • Pressing and fat separation
  • Meal drying systems
  • Raw material storage and handling
  • Cooling conveyors
  • Cooking and rendering processes
  • Fat coating systems
  • Extruders and dryers
  • Grinding and milling operations

These sources generate highly variable emissions, often combining odorous compounds, moisture and aerosols.

Because of this variability, air treatment systems must be designed around real process conditions rather than nominal airflow values.

Typical Pollutants

Air emissions from pet food production contain a mixture of inorganic and organic compounds.
Facilities processing ABP Cat.3 typically generate emissions rich in amines, ammonia, sulfur compounds and fat aerosols.
These emissions originate from thermal processing, raw material storage and meal drying operations.


Common pollutants include:

Many of these substances are water soluble or chemically reactive, which makes wet scrubbing technologies particularly effective when properly engineered.

Technologies Used

Different emission sources require different treatment approaches.

industrial air pollution control system showing vertical scrubber column and exhaust duct layout

Variable Throat Venturi Scrubbers

Venturi scrubbers are highly effective for aerosol and fine particulate removal, commonly present in exhaust streams from dryers and cooking systems.
Systems with variable throat Venturi allow adjustment of the pressure drop, maintaining separation efficiency under fluctuating airflow conditions typical of industrial processes.

Wet Scrubbers

Industrial wet scrubbers are widely used for ammonia removal, soluble VOC absorption and odour control in pet food processing plants.
Multi-stage scrubbers combine acid and oxidizing chemistry to treat complex pollutant mixtures generated during cooking, drying and raw material handling operations.

multistage wet scrubber for category 3 animal by-products processing emissions

Compact Multi-Stage Venturi Scrubber Systems

Compact systems combining variable throat Venturi scrubbing and multi-stage wet treatment are designed for exhaust streams containing aerosols, ammonia and complex odour mixtures.
These systems integrate Venturi aerosol removal with acid and alkaline-oxidizing scrubbing stages, providing efficient treatment of cooking and drying emissions.

FAQ – Pet Food and ABP Cat.3 Air Emissions

Air emissions typically include ammonia (NH₃), hydrogen sulfide (H₂S), amines, volatile organic compounds (VOCs), odorous sulfur compounds, aerosols, and organic particulate matter generated during cooking, drying, and raw material handling.

Odour emissions are highly variable and often intense due to organic decomposition and thermal processes. Effective odour control is essential to meet environmental regulations, avoid complaints, and ensure continuous plant operation.

No. Standard HVAC systems are not designed for industrial process emissions. Pet food and ABP processing require dedicated industrial air pollution control systems engineered for chemical reactions, high humidity, and pollutant variability.

The main challenge is variability: fluctuating airflow, intermittent odour peaks, high humidity, and complex pollutant mixtures. Systems must be designed based on real process conditions, not nominal airflow values.

Typical solutions include:
– Wet scrubbers (acidic, alkaline, oxidizing stages)
– Variable throat Venturi scrubbers for aerosol removal
– Multi-stage scrubber systems combining chemical absorption and particulate removal
The correct configuration depends on the specific emission profile.

Venturi scrubbers are highly effective for removing fine particulate and fat/protein aerosols generated in cooking and drying processes. Variable throat designs allow adaptation to changing airflow conditions.

Not always, but in most cases involving Category 3 animal by-products, multi-stage systems are necessary due to the presence of mixed pollutants (acidic, basic, and organic compounds) that require different treatment chemistries.

In the EU, pet food and ABP Category 3 facilities fall under the Industrial Emissions Directive (IED) and must comply with BAT Conclusions. This requires systems designed for measurable performance on odour, ammonia, and process emissions.

Because emissions are generated by the process itself. Without a clear understanding of cooking, drying, and handling conditions, it is impossible to correctly size or select an effective air pollution control system.

Request a Technical Evaluation for Your Air Emissions

Get a process-based assessment of your air emissions in pet food and Category 3 animal by-products processing.

We analyse your real operating conditions — not just nominal airflow — to identify the most effective air pollution control strategy.

From ammonia and odour control to aerosol and VOC removal, each solution is engineered around your process, not adapted from standard systems.