Spouted bed reactor for VOC removal by modified nano-TiO2 photocatalytic particles

Samples of N-doped, F-doped and N-F codoped TiO2 nanoparticles were synthesized by physical and chemical treatments. X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), Brunauer-Emmett-Teller technique (BET) and UV-vis diffuse reflectance spectroscopy (DRS) were used to characterize the prepared powders. FTIR analysis confirmed that nitrogen and fluorine were replaced in the oxygen sites of TiO2 structure. DRS analysis has revealed that absorption spectra of the N-doped and F-N-TiO2 samples were significantly extended to the visible light region. The photocatalytic activity of the prepared samples was evaluated through the process of acetaldehyde degradation under Hg lamp in a high flow rate spouted bed reactor. F-N-TiO2 sample degraded 98.2% of 1000 ppm acetaldehyde in the spouted bed reactor with a flow rate of 1000 ml/min. The high photocatalytic activity of TiO2 in the spouted bed reactor can be due to the enhanced properties of modified TiO2 as well as efficient hydrodynamics, effective light scattering to the particles and low mass transfer resistance in spouting conditions. The Langmuir kinetic model was adapted for photocatalytic degradation of acetaldehyde and its kinetic parameters were specified experimentally.