We abate VOCs by thermal oxidation with up to 99% efficiency. Three technologies: regenerative, recuperative and catalytic for every combination of flow rate, concentration and solvent. When recovery is not possible, oxidation is the answer.
VOC abatement efficiency
Thermal efficiency (RTO)
RTOs and TOs installed worldwide
The principle is straightforward: VOC-laden air is brought to combustion temperature, typically 750–950°C, and the organic compounds are oxidised into CO₂ and H₂O. The difference between the three technologies lies in how the generated heat is recovered.
We draw VOC-laden air from the production machines with a main fan. Before it enters the oxidiser, we filter it to remove particulates that could compromise system operation.
In the RTO, air enters the ceramic chamber, which has already accumulated heat from the previous cycle: the ceramic bed preheats the polluted air before it reaches the combustion chamber, reducing support gas consumption. In the recuperative oxidiser, pre-heating takes place via an air-to-air heat exchanger.
Pre-heated air enters the combustion chamber where VOCs are oxidised at 750–950°C. The support burner only intervenes when the VOC concentration is insufficient to maintain temperature autothermally. At high concentrations, the process is fully autothermal.
Purified flue gases transfer their heat to the opposite ceramic chamber or to the heat exchanger, before being discharged to the atmosphere within regulatory limits.
The choice between RTO, recuperative oxidiser, and catalytic oxidation depends on airflow rate, VOC concentration, and process continuity. We offer three technologies and analyses to help you choose the right one.
The regenerative oxidiser uses a heat recovery system based on structured ceramic media. Hot flue gases transfer heat to the ceramic bed; the heat is then returned to the incoming polluted air in the next cycle. Thermal efficiency up to 96%, abatement efficiency up to 99%. Over 800 units installed worldwide. Available in Full Electric version (no gas burner) and for CO₂ emission reduction.
The recuperative oxidiser recovers heat by thermal oil or steam generation returning energy directly to the client's production process.Excess heat from the flue gases can be used to pre-heat the process gas to be purified or the pre-heat the combustion air.Suitable for processes with high and variable VOCs concentrations or too dirty flow rates for being treated by an RTO.
Catalytic oxidation allows VOCs to be treated at significantly lower temperatures than traditional thermal oxidation, 300–350°C instead of 750–950°C. The catalyst abates organic compounds, reducing fuel consumption. Achievable emission limits below 1 mg/Nm³. Autothermal process when the concentration is sufficient. Suitable for low-concentration streams with stable composition free of catalyst-poisoning substances.
Our RTOs and TOs achieve up to 99% VOC abatement efficiency and up to 96% thermal efficiency. Performance documented across more than 800 installations worldwide, in sectors ranging from flexible packaging to waste treatment.
When the VOC concentration is sufficient, the heat produced by oxidation exceeds the heat required by the process. Excess heat is recovered to generate thermal oil, steam, or hot air for reuse in production, reducing the plant's overall energy costs.
We offer advanced solutions to reduce the RTO's CO₂ emissions: the Full Electric version, with electric heating instead of a gas burner. These technologies eliminate or significantly reduce CO₂ emissions from combustion.
Our RTOs are designed to minimise routine and unscheduled maintenance interventions. First-choice materials and components, remote supervision from our offices and maintenance contracts through the Babcock Wanson Group guarantee high operational availability throughout the plant's service life.
Thermal oxidation applies wherever VOC emissions cannot be economically recovered due to too low a concentration, too variable a composition or insufficient volumes to justify recovery.
RTO as backup to solvent recovery, or main solution for lines with mixed low-concentration solvents. Flow rates up to 330,000 Nm³/h.
RTOs for batch processes with variable composition are incompatible with recovery. ATEX design, management of concentration peaks.
Production and recycling of automotive Li-ion battery production.
Odour and VOC abatement from food processing (e.g.: frying), rendering, flavours and fragrancies production. TOs and RTOs with minimised NOₓ and CO emissions
RTOs for low-concentration streams not suitable for recovery. Integration with upstream VOC concentration systems to reduce operating costs.
RTOs integrated with scrubbers and bag filters for complex streams containing VOCs, HCl, SOx and particulates. Recycling of chillers components leaded with fluor hydro-carbon.
The RTO is the optimal choice for high flow rates (above 10,000 Nm³/h up to 300,000 Nm³/h) and low concentrations (up to 10 g/Nm3), as its high thermal efficiency minimises gas consumption. We recommend the recuperative oxidiser for moderate flow rates. Catalytic oxidation works best when the VOC concentration is low and constant, solvents do not contain silicon or chlorine, and minimising process temperature is a priority.
Yes. The RTO reaches autothermal operation, without support-gas consumption, when the VOC concentration in the inlet air is sufficient to generate the heat required to maintain the combustion temperature. The threshold depends on the solvent type and the plant's thermal efficiency: typically, it is between 1 and 3 g/Nm³ for common solvents such as toluene and ethyl acetate.
When the VOC concentration exceeds the autothermal threshold, excess heat can be recovered via a heat exchanger installed downstream of the RTO to generate thermal oil, steam or hot air. The amount of recoverable heat depends on VOC concentration, flow rate and solvent type. It is calculated during the project design phase based on real process data.
Donau Carbon Technologiesoffers: the Full Electric version, which replaces the gas burner with electric resistance heating, completely eliminating combustion emissions.
Our RTOs are designed to comply with the BAT-AEL values defined by the IED Directive for the relevant sector. VOC abatement efficiency is up to 99%. CO and NOₓ emissions are minimised through the design of the combustion chamber and the choice of burner. Specific limits depend on the solvent, flow rate and country of installation, and are defined during the project design phase.
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