Inaugural US-EU-China Thermophysics Conference-Renewable Energy 2009 (UECTC 2009 Proceedings)
84 Study on the Effect of Mass Transfer on the Photocatalytic Removal of Formaldehyde
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- Ris (Zotero)
- Reference Manager
Photocatalysis is an emerging and promising technology for indoor air purification. This purifying method features the good performance at the higher pollutant concentration, in contrast to the lower concentration. This feature limits the technique to be widely used in indoor air purification, in that the contaminant levels of indoor air is usually low. In this study, the formaldehyde (HCHO) was used as target pollutant and the nanometer TiO2 particles were immobilized on the surface of an activated carbon (AC) to explore the influence of mass transfer due to the absorption of AC on the photocatalytic reaction rate and removal rate of HCHO. The experimental results showed that the photocatalytic reaction rate was improved because the adsorbent AC can absorb the pollutants from the diluted air stream to the surface of catalyst. The results also showed that the photocatalytic reaction consisted of mass transfer control process and photocatalytic reaction control process with the increasing of flow velocity. During the mass transfer control process, the photocatalytic reaction rate increased with the increasing of flow velocity, while in the photocatalytic reaction control process photocatalytic reaction rate changed very little. Compared with the results by the TiO2∕glass film, the switch point of the photocatalytic reaction from the mass transfer control process to the photocatalytic reaction control process was advanced by the TiO2∕AC film. At the same time, the indoor HCHO with low concentration could be degraded to the standard range which is specified by the standard of indoor air quality by TiO2∕AC film.