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Exhaust air purification in coffee roasting – efficient and energy-generating

Clean air, reduced odors, and usable waste heat with Oxytec Clean Fryer Air systems

Roasting coffee produces particularly complex emissions: hot smoke, intense roasting aromas, grease and tar-containing vapors, and VOCs, which are not only unpleasant in terms of odor but also technically challenging. At the same time, the exhaust air contains large amounts of energy that is lost unused in many roasteries.

The solution: oxytec Clean Fryer Air systems, which not only reliably neutralize odors and pollutants, but also make the hot roasting exhaust air usable for energy. This makes exhaust air purification an integral part of an efficient and sustainable production concept.

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Typical emission sources in coffee roasting

Process Typical emissions Special features
Roasting process VOCs, roasting fumes, coffee oil, CO₂, smoke particles Very hot, rich in fat and aroma
Emptying/cooling Aromatic substances, roasting fumes, condensate particles Pulse emissions, diffuse outgassing
Cleaning / cyclone emptying Dust, residues, thermal cleaning bursts Short-term but high load

Why exhaust air purification in coffee roasting plants?

Even in the smallest quantities, coffee roasting aromas have a strong effect on odors.

Fat, oil, and tar residues settle in the ventilation system and chimney.

Without heat recovery, the hot roasting air leads to high energy losses.

Permits are required in accordance with TA Luft, GIRL, and, if applicable, BImSchG.

Complaints, rejection of permits, or subsequent requirements are common in the absence of exhaust air technology.

Legal requirements

  • TA Luft (2021): Limit values for VOCs, organic substances, odor
  • GIRL (Odor Emission Directive): applicable in proximity to residential or mixed-use areas
  • BImSchG / 31. BImSchV: Approval required for larger production volumes
  • Hygiene and fire protection requirements for exhaust air containing grease and tar

oxytec provides all necessary evidence, measurement reports, and documentation suitable for official authorities.

Get advice now – for energy-efficient, odor-free coffee roasting

Would you like to reduce emissions, recover energy, and at the same time work in compliance with regulations?

Contact us—we will develop your individual solution for exhaust air purification in coffee roasting.

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oxytec systems for coffee roasting

Clean Fryer Air – UV ozone technology for roasted aromas

Photochemically breaks down VOCs, smoke substances, and odor molecules
Ozone oxidation destroys even stubborn roasting aromas without leaving any residue
Ideal for continuous and batch roasting processes
No open flame, no fuel, no filter clogging

Heat recovery – returning energy to the process

Can be combined with air-to-air or air-to-water heat exchangers

Can be used for fresh air heating, process heat, or heating support

CO₂ savings thanks to lower primary energy requirements

Particularly efficient for continuous roasters, large batches, or 2- to 3-shift operation

Pre-filter stages for grease and particles

Protection of the UV chamber by metal filters, cyclone separators, or droplet separators

Low-maintenance design – adaptable to individual loads

Optional with automated contamination detection

Production heat can also be generated more economically

The heat for ovens, deep fryers, or Teflon roasters can be controlled to the exact degree with thermal oil heating systems to create perfect production conditions. Another advantage is that only the heat required for the process is generated, and no more.

The heat from a TNV, on the other hand, must first be cooled down. Energy is lost both when heating up the combustion plant and when reducing the temperature.

The argument that a CHP plant is particularly economical due to the secondary heat it generates is misguided in two respects: exhaust air can also be cleaned to the legally permitted level with 20% of the energy input, and the heating of the systems can also be carried out much more economically than with the waste heat from the CHP plant.

With our subsidiary Condoheat, we plan, build, and maintain thermal oil heating systems for production facilities. This enables oxytec to implement an integrated energy concept for the entire production operation that meets the highest standards of quality and sustainability.

Typical areas of application

Specialty artisanal roasters

Industrial drum or fluid bed roasters

Combined roasting/packaging lines in urban environments

Organic, Fairtrade, and specialty coffee facilities that prioritize sustainability

Your advantages with oxytec Clean Fryer Air

Odor reduction >90%, even with intense roasting aromas

Residue-free operation – no soot, no filter replacement

Heat recovery saves energy and reduces CO₂ emissions

No open flame – no gas, no exhaust gas aftertreatment necessary

Modular, compact, and retrofittable, even for smaller businesses

Approval-secure, future-proof, and economically plannable

FAQ – Frequently Asked Questions

What emissions are produced during coffee roasting?

During the roasting process, the following are produced:

  • Hot water vapor with CO₂ and aromatic vapors
  • Roasting aromas (e.g., aldehydes, phenols, acids)
  • Coffee oils, tar substances, and fine smoke particles
  • VOC-containing shock emissions during batch changes and cleaning

These substances are extremely odorous, greasy, sticky, and filter-clogging—they make targeted exhaust air treatment technically and legally necessary.

How does the Clean Fryer Air System from oxytec work in practice?
  • UV-C light breaks down organic molecules in exhaust air
  • Ozone oxidation decomposes odors and VOCs without leaving any residue
  • The technology works dry, without filter clogging or combustion
  • No impact on the product or roasting quality

The system is particularly suitable for continuous and batch roasters.

What happens to the grease and tar components in the exhaust air?

These are separated by upstream pre-filter stages:

  • Metal mesh or coalescence filters for grease and oil
  • Droplet separators or cyclones for higher air volumes
  • Optional: automatic monitoring of the degree of contamination

This keeps the UV ozone chamber free of deposits and ensures long-term functionality.

How is the waste heat from the roasting air utilized?

oxytec offers integrated heat recovery, e.g. via:

  • Air-to-air heat exchangers for fresh air heating
  • Air-water systems for heating or process water supply
  • Use for preheating the roasting process, room air, or cleaning water

This saves energy, CO₂, and operating costs—especially in multi-shift operation.

How much does it reduce odors?

In practice, Oxytec systems achieve:

  • > 90 % reduction in odor-active substances
  • Effectiveness even with coffee acids, smoke, and aromatic substances
  • Verifiable by:
    – Olfactometric measurement (EN 13725)
    – VOC analysis (TA Luft / VDI 3880)

How energy-efficient is the system compared to post-combustion?

Highly efficient:

  • Purely electric operation, no gas consumption
  • Typical power consumption: 0.5–1.5 kWh per 1,000 m³ of exhaust air
  • No flames, no heating, no exhaust gas aftertreatment
    → Up to 60% energy savings compared to TNV

How maintenance-intensive is the system?

Clean Fryer Air requires little maintenance:

  • UV lamps: approx. 8,000–10,000 operating hours
  • Filter maintenance: every 4–8 weeks, depending on load
  • No filter changes as with activated carbon or TNV systems
  • Optional: maintenance contract with remote monitoring and fault reporting

Is the system subject to approval or notification?

oxytec systems are:

  • Compliant with TA Luft and GIRL
  • Approved in accordance with BImSchG for corresponding production sizes
  • Retrofittable even in existing plants without modification approval
  • We provide support with:
  • Measurement documents, emission certificates, and official documentation

Can the system also be integrated into smaller roasting facilities?

Yes – the Clean Fryer Air System is:

  • modular in design, also suitable for manufacturers and specialty roasters
  • can be implemented as an inline solution or external container module
  • ideal for retrofitting in confined spaces or during ongoing operation