Adsorbent Regeneration by Non‐thermal Plasma for Elimination of Odorous Compounds from Indoor Air

The non‐thermal plasma (NTP) technique was shown to be a method to improve indoor air quality. In particular in kitchens, odorous emissions can be removed by NTP. A combined concept of adsorption of volatile organic compounds (VOCs) and plasma regeneration of the adsorber was tested in adsorption‐regeneration‐adsorption cycles. As reference VOCs, 2‐methylthiophene, 2‐methylpyrazine, 2‐acetylthiazole, nonanal, and trans‐2‐nonenal were selected in humid air streams. These odorous compounds are emitted during cooking and frying processes. The adsorption‐regeneration concept was also tested during a simulated frying process with garlic in rape oil. A hydrophobic zeolite was chosen as adsorber material and placed directly into the discharge zone of a plasma reactor. Odorous compounds are removed from indoor air by a combined concept of adsorption and plasma regeneration. Regeneration is carried out by non‐thermal plasma oxidation. The concept was successfully demonstrated for model compounds and real odors. Adsorbed compounds could be eliminated to a high degree by regenerating the adsorber. A combination with ozone removal and CO post‐oxidation is favored.