Modelling and experimental validation of reaction chamber simulating indoor air decontamination by photocatalytic paint

A photocatalytic paint for the air decontamination was tested under different operating conditions in a reaction chamber that simulates an indoor room. An experimental design was applied to cover a wide range of indoor air conditions (irradiation level, air flow rate, relative humidity and inlet pollutant concentration). It was proposed to develop a first principles model capable of predicting the outlet contaminant concentration from the continuous reaction chamber or the evolution of the reactant concentration operating the chamber in batch mode. The main inputs for the model were: i) optical properties of the paint, ii) characteristics and dimensions of the radiation source, iii) dimensions and operating conditions of the reaction chamber, and iv) intrinsic photocatalytic kinetics previously determined. The developed models showed a very good agreement with experimental measurements. The proposed methodology could be extended considering all indoor environmental conditions to simulate air decontamination in real applications of photocatalytic paints.