Indoor Air Purification Using Activated Carbon Adsorbers: Regeneration Using Catalytic Combustion of Intermediately Stored VOC

In this study, we demonstrate a two-step process where activated carbon based air purifier systems can be regenerated in situ and eliminate volatile organic compounds (VOCs) from indoor air in an energy efficient way. A carbon based adsorber was combined in series with a CeO2/TiO2 oxidative catalyst for total oxidation of the previously adsorbed and periodically released volatile organic compounds during regeneration runs. We investigated the adsorption and desorption behavior of five different VOCs (diethyl ether, limonene, linalool, hexanoic acid, triethylamine and n-decane) with thermogravimetric measurements, mass spectrometry and elemental analysis. Cyclic loading and regeneration experiments were carried out with selected VOCs (limonene, linalool and n-decane) for testing regeneration at elevated temperature. We showed that in situ thermal regeneration and subsequent oxidation of released VOC is a sustainable and easy applicable technology for indoor air purification. This two-step approach allows energy saving as the VOCs are eliminated discontinuously (enriching VOCs; periodic catalytic combustion), and is of high environmental and economic interest, as much less maintenance services are required.