UV photooxidation process
The principle of direct photooxidation (DF)
The wide range of applications for photo-oxidation in the removal of pollutants from gaseous or liquid media is based on the innovative, patented processes we have developed:
Flowchart
Cleaning the air flow
In the field of exhaust air purification, the main air stream containing VOCs (volatile organic compounds) is first passed through a coarse/fine filtration stage, depending on the air quality, and, if necessary, through a droplet separator stage.
UV photooxidation
The air flow then passes through the UV reactor, which is fitted with either low-pressure or medium-pressure UV lamps, depending on the application. Here, the pollutants are converted by oxidation and, ideally, completely broken down into carbon dioxide (CO₂) and water (H₂O).
Catalyst
To optimise performance, a catalytic stage may be installed downstream in the absence of catalyst poisons. In many cases, however, at least one stage is provided to destroy any excess ozone that is formed.
Direct photooxidation is also used successfully in the field of wastewater treatment.
The principle of regenerative photooxidation (RF/RF+CAT)
Flowchart
Purification by adsorption
The VOC-laden exhaust air flow is directed alternately through two parallel adsorption stages. In this process, the fluctuating VOC loads—whether high or low in concentration—are completely removed to meet the required emission limits through adsorption using a suitable adsorbent. The resulting exhaust air consistently meets the required clean air limits.
Regeneration cycle
Even before the adsorbent is exhausted, the system switches to the second, parallel fresh adsorption stage. The first stage then enters a UV operation phase within the regeneration cycle. During this process, the recirculating air is passed through a UV stage and then through a catalytic stage before returning to the adsorption stage.
Energy efficiency through synergy
The energy from the UV radiation heats the recirculating air to the operating temperatures required for the desorption and regeneration of the adsorbent, as well as for the operation of the catalytic stage.
UV photooxidation
The organic pollutants previously adsorbed are rapidly and uniformly desorbed from the adsorption stage under defined conditions and fed into the recirculating air stream for UV photo-oxidation followed by catalytic treatment. Here, the pollutants are broken down by photo-oxidation into CO₂ and H₂O.
Scalability
The system can be expanded and retrofitted on a modular basis to cope with increasing airflows or rising pollutant concentrations resulting from production processes.
The concept of regenerative photooxidation is equally applicable to wastewater treatment.