Exhaust air purification for manure and agricultural by-products – controlling odors, protecting processes
oxytec systems for reducing emissions during storage, drying, and processing of manure, dung, pomace, and crop residues
In modern agriculture, large quantities of organic by-products are generated in addition to manure, including stable manure, press residues, harvest residues, dry matter, and fermentable residues. Their storage, drying, or energy recovery produces strong-smelling, ammonia-containing, and VOC-contaminated exhaust air streams. These not only harm the environment, but also affect permits, neighborhood relations, and the technical stability of exhaust air systems.
Oxytec technologies can be used to purify this exhaust air and neutralize odors, even under difficult conditions and with large air volumes.
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Typical emissions from the utilization of agricultural by-products
| Process step | Typical pollutants | Special features |
|---|---|---|
| Slurry storage / lagoon | Ammonia, sulfur compounds, odors | Long-term emissions, dependent on weather and pH |
| Drying / processing | VOCs, ammonia, aerosols, germs | Moist, warm exhaust air with high odor intensity |
| Biogas plant / pre-pit | Digester gases, CO₂, CH₄, H₂S, organic residues | Explosion protection relevant, diffusive emissions |
| Presses / dewatering | Moist ammonia vapors, aerosols | Fluctuating load, sticky components |
Why exhaust air purification is so important here
Ammonia and H₂S are considered harmful to the environment and health.
Odors cause discomfort and can lead to stricter regulations.
Without cleaning, there is a risk of exceeding the limits set by TA Luft (Technical Instructions on Air Quality Control).
Filters, pipes, and heat exchangers are contaminated by aerosols and fats.
Legal requirements
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TA Luft 2021: Limit values for ammonia, VOCs, and odorous substances
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BImSchG / 4. BImSchV: Permit requirement for drying and recycling plants
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GIRL: Odor emissions in proximity to residential or mixed-use areas
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Funding opportunities, e.g., for low-emission livestock housing technology or circular economy
oxytec provides support with application documents, emission certificates, and communication with authorities.
Get advice now – for clean air in the agricultural sector
Would you like to utilize manure, dung, and by-products efficiently, with low emissions, and in compliance with regulations?
Contact us—we will plan the right exhaust air solution for your agricultural or biogas plant.
oxytec solutions for agricultural exhaust air
UV ozone systems for odor reduction
Decomposes organic odorous substances, ammonia, and sulfur compounds
Reaction is dry, residue-free, and without thermal processes
Suitable for humid air with varying loads
Aerosol separator for dust and moisture
Removes fatty acids, dust particles, germs, and mist droplets
Protects downstream cleaning units
Modular and low pressure loss even with large air volumes
Activated carbon for fine cleaning
Adsorbs persistent VOCs and residual odors
Long service life thanks to pre-cleaning with UV systems
Suitable for stationary or mobile units
Other areas of application
Slurry and manure storage (open or covered)
Drying facilities for fermentation residues and fertilizers
Processing stations for pressed pulp or straw pellets
Biogas plants and pre-pits with emissions from substrates
Typical areas of application
Slurry and manure storage (open or covered)
Drying facilities for fermentation residues and fertilizers
Processing stations for pressed pulp or straw pellets
Biogas plants and pre-pits with emissions from substrates
FAQ – Frequently Asked Questions
What emissions typically arise from slurry and manure?
Mainly:
- Ammonia (NH₃)
- Sulfur compounds (e.g., hydrogen sulfide, mercaptans)
- Organic odorants (e.g., butyric acid, indole, skatole)
- Aerosols and bioaerosols
- Moisture and dust from drying by-products
These emissions are odorous, corrosive, and difficult to filter, especially when outdoor temperatures fluctuate.
How does odor reduction work with Oxytec systems?
Oxytec systems work with UV-C light and active ozone, which oxidizes pollutants.
Ammonia, sulfur compounds, and VOCs are converted into harmless end products.
The cleaning process is dry, chemical-free, and leaves no residue.
Is the system suitable for highly humid or sticky exhaust air?
Yes – the systems are specially designed for:
- moist, warm exhaust air from manure or drying processes
- fluctuating loads (e.g., in batch operation or when the weather changes)
- Separation of aerosols and droplets by upstream modules
How are open slurry tanks or pre-pits treated?
For open sources, hoods, point extraction systems, or cover systems can be combined with Oxytec systems.
Exhaust air from pre-pits, pumping stations, or pipelines can be extracted and treated in a targeted manner.
Which systems are used?
Oxytec usually designs multi-stage systems consisting of:
- Aerosol separators or droplet separators
- UV ozone module for oxidation of odorous substances
- Optional: Activated carbon polishing for residual removal in the case of particularly critical substances
How much does it reduce odors?
Depending on the process, up to 90–95% reduction in odor pollution
Verifiable by olfactometric measurements (EN 13725)
Additional VOC measurements or ammonia analysis possible
Does the system require approval?
Generally not, if it involves improving existing exhaust air systems.
For new installations or expansions, approval is granted in accordance with the Federal Immission Control Act (BImSchG), TA Luft (Technical Instructions on Air Quality Control), and, if applicable, GIRL (Guidelines for the Assessment of Noise and Vibration).
Oxytec provides support with technical documentation and discussions with authorities.
How maintenance-intensive are the systems?
UV lamps: Service life approx. 8,000–10,000 operating hours
Pre-separator: Cleaning depending on dust load (monthly to quarterly)
Activated carbon (if present): Replacement interval approx. 6–12 months
Optional: Maintenance contract with remote monitoring
Are there any funding opportunities?
Yes – especially about:
- Agricultural environmental support programs (e.g., for low-emission technology)
- Subsidies for energy-efficient process heat utilization or exhaust air systems
- Municipal air pollution control or odor reduction programs
Oxytec can provide eligible technical project documentation upon request.
