Reinigung von lösemittelhaltiger Prozessabluft in Biorieselbettreaktoren

In numerous industrial processes, solvent-containing exhaust gas is generated and has to be purified to comply with the emission limits prescribed by law. However, conventional exhaust gas purification technologies, such as thermal post-combustion, require high temperatures of 1200 °C and often fossil fuels. As a significantly more sustainable alternative, biotrickling filters enable biodegradation at 20 °C. The pollutants are converted into harmless substances by bacteria in a biofilm on lava stones.     

Umsetzung der TA Luft 2002 in Altanlagen am Beispiel eines Biowäschers zur Abluft‐ und Abwasserbehandlung

The TA Luft 2002 became effective for existing plants in November 2007. Caused by a significant tightening of waste air limit values, biological treatment processes seemed to be non realistic to obtain these values and were substituted by non‐biological techniques. To demonstrate the applicability of biological treatment systems, a bioscrubber system, which was not conformable to the TA Luft 2002 values, was investigated. The progress of modernisation of the biological process was accompanied by analytical measurement directly on‐site. The compound specific degradation potential of the plant was verified in laboratory scale.     

Bioabbaubarkeit von 2‐Ethylhexylacetat,Methylisobutylketon und Methylethylketon in Biotricklingfiltern

The impact of nutrient supply and package material on the biodegradability of a waste air contaminated with a mixture of 2‐ethyl hexyl acetate, methyl isobutyl ketone and methyl ethyl ketone in biotrickling filters was analyzed. As package material PU foam cubes, Hiflow rings and woodchips were used. The data showed that PU‐cubes gave the best results in degradation, while the Hiflow rings showed the most stable usage. The discontinuous supply of nutrients helped to improve and stabilize efficiency in all three systems. Inhibitory effects based on the degradation of these components were not observed.     

Dielektrische Erwärmung von Zeolithen mittels Radiowellen – Selektivität,thermo‐chromatographischer Puls und Trocknen mit Wasser

Dielectric heating with radio‐frequency energy can be applied for a wide spectrum of dry or moist zeolites. It is possible to homogeneously heat packed beds in technical scale. The energy absorption strongly varies with the zeolite type enabling selective heating of layered arrangements containing different zeolites. The specific effect of water interacting with the structural cations allows establishing pronounced temperature gradients within a packed bed with varying water content. For distinct materials such as zeolite NaY, a coupled water‐temperature pulse moving through the packed bed can be established. Potential applications for such a so‐called thermo‐chromatographic pulse range from adsorptive catalytic off‐gas cleaning to thermal regeneration of zeolites in the context of gas drying.     

Biologische Abluftreinigung einer Lackierabluft im Kombinationsverfahren

This study describes an approach to improve an industrial scale biofilter as biological waste air cleaning plant for the treatment of VOC emissions created by dip spin coating of metallic components. The compounds in the waste air with equal ratios are mainly the hydrophilic methoxypropyl acetate and lipophilic xylene isomers. After a pilot‐scale biofilter proved inefficient due to efficiencies lower than 20 %, the proposed solution was a combination of a bioscrubber and a downstream biotrickling filter. The system was stable and maintained a long term removal efficiency of 75 %.