A commercially available TiO2 type (Kronos vlp 7000), doped with carbon and having an extended spectrum of light absorption wavelength, is investigated for photocatalytic degradation of a representative air pollutant, namely acetaldehyde, under visible light. The modeling of the studied system was carried out including the proposal of kinetic expressions for the contaminant degradation and generation of main intermediates based on the reaction mechanism, the mass balances in the reactor, and the lamps' superficial emission model to evaluate the radiation distribution in the reaction space. The predicted and experimental outlet concentrations of acetaldehyde and formaldehyde as main intermediate were found to be in good agreement obtaining a root mean square error equal to 13 %.