The modern chemical industry is increasingly focused on environmental protection. One of the key challenges is reducing harmful emissions released during industrial processes. This is where catalytic afterburners (C&Cs) come into play, having established themselves as an efficient solution for minimizing volatile organic compounds (VOCs) and other pollutants. This article examines the operation, advantages, and applications of C&Cs and the contribution made by C&Cs.
How KNV systems work
The fundamental function of a KNV system is to heat the exhaust gas to a temperature at which the catalytic reaction proceeds optimally. This range is typically between 300°C and 500°C, significantly lower than that of thermal afterburners, which require temperatures above 700°C. These low operating temperatures are achieved through the use of a catalyst; those made of platinum, such as the C&CS Envicat 2531, or of platinum and palladium, such as our C&CS Envicat 55068, are best suited.
A catalyst – usually made of precious metals such as platinum or palladium – is used to lower the activation energy of the oxidation and thereby increase the reaction rate.
By using a catalyst in such oxidation technology, combustion can be carried out at lower temperatures, which not only saves energy but also minimizes the formation of byproducts such as nitrogen oxides (NOₓ). This characteristic makes KNV systems particularly attractive for applications where the reduction of both VOCs and NOₓ is crucial.
Advantages of KNV technology
KNV technology offers several advantages over traditional exhaust gas treatment methods:
- Hohe Effizienz bei der Schadstoffreduktion: KNV-Anlagen können eine VOC-Reduktion von über 95 % erreichen, was sie besonders effektiv bei der Kontrolle industrieller Emissionen macht.
- Energy savings: Due to lower operating temperatures compared to thermal afterburner systems, KNV systems consume significantly less energy. This results in lower operating costs and a smaller CO₂ footprint.
- Reduced NOₓ emissions: The lower operating temperature also helps to significantly reduce the formation of nitrogen oxides, which can occur at higher temperatures.
Applications and challenges
KNV systems are used in a wide variety of industries, including chemical production, paint shops, petroleum refining, and plastics manufacturing. Wherever organic solvents are used or VOCs are produced as byproducts, KNV systems are an indispensable tool for emission control – see the German Technical Instructions on Air Quality Control (TA Luft) for further information.
Despite their advantages, KNV plants also face some challenges. One of these is catalyst poisoning, where certain contaminants such as sulfur compounds or chlorine can impair the catalyst’s activity. This necessitates careful monitoring of process conditions and may require the use of special catalysts that are more resistant to such impurities. We support our customers in the design process in this regard.
Another challenge is the need to pretreat the exhaust gases to ensure the efficiency of catalytic oxidation. This can be achieved through the use of heat exchangers or other methods to preheat the exhaust gas stream.
Conclusion
Catalytic afterburners are a crucial tool for reducing harmful emissions in the chemical industry. They offer an energy-efficient and environmentally friendly solution for effectively removing VOCs and other pollutants. Despite some technical challenges, the advantages outweigh the disadvantages, particularly regarding energy savings and the reduction of NOₓ emissions. At C&CS, we are proud to contribute our expertise in catalyst design to environmental protection and to advise our customers.
If you have any questions about this or any other topic, please feel free to contact us!
