International Journal of Photoenergy 
Volume 2008 (2008), Article ID 759736, 7 pages
doi:10.1155/2008/759736
Research Article

A Photocatalytic Active Adsorbent for Gas Cleaning in a Fixed Bed Reactor

Peter Pucher,1 Rabah Azouani,2 Andrei Kanaev,2 and Gernot Krammer3

 1Department of Chemical Apparatus Design, Particle Technology and Combustion, Graz University of Technology, Inffeldgasse 25/B, 8010 Graz, Austria
2Laboratoire d'Ingénierie des Matériaux et des Hautes Pressions, CNRS, Institut Galilée, Université Paris-Nord, 93430 Villetaneuse, France
3Department of Energy and Process Engineering, Norwegian University of Science and Technology, Kolbjørn Hejes vei 1, 7491 Trondheim, Norway
Received 24 July 2007; Accepted 27 February 2008

Recommended by Russell Howe

Abstract

Efficient photocatalysis for gas cleaning purposes requires a large accessible, illuminated active surface in a simple and compact reactor. Conventional concepts use powdered catalysts, which are nontransparent. Hence a uniform distribution of light is difficult to be attained. Our approach is based on a coarse granular, UV-A light transparent, and highly porous adsorbent that can be used in a simple fixed bed reactor. A novel sol-gel process with rapid micro mixing is used to coat a porous silica substrate with TiO2-based nanoparticles. The resulting material posses a high adsorption capacity and a photocatalytic activity under UV-A illumination (PCAA = photocatalytic active adsorbent). Its photocatalytic performance was studied on the oxidation of trichloroethylene (TCE) in a fixed bed reactor setup in continuous and discontinuous operation modes. Continuous operation resulted in a higher conversion rate due to less slip while discontinuous operation is superior for a total oxidation to CO2 due to a user-defined longer residence time.