The Study On The Dynamic System For Evaluating The Photocatalytic Performance

At present, indoor air pollution is a major problem worldwide. However, the traditional air purification technology can not remove indoor gas pollutants. Photocatalytic air purification is a novel and highly effective technology for air purification has been a major topic in the world. Many researches on the activity of photocatalysts and their loading technology have been studied in order to get better catalytic efficiency. So it is necessary to establish a system to evaluate the catalytic performance and the loading method. The objects of this paper are to remove the representative organic contaminants-formaldehyde in indoor air by photocatalytic oxidation processes and to establish a reliable system to test the performance of the catalysts.The main contents were focused on the principle of gas-solid phase photocatalytic reaction, the design and establishment of a continuous flow photocatalytic system including the fixed-bed gas-solid photo-reactor, the photocatalytic behaviors on the degradation of HCHO, the examination of related influencing factors, and the evaluation of different catalysts in the continuous flow system. The gas-solid photocatalytic reaction was studied on the batch photocatalytic reactor and the honeycomb reactor. It is concluded that the continuous flow system is practicable through comparison of merits and drawbacks about the batch reactor and the honeycomb reactor. The continuous flow single-pass photocatalytic system includes the HCHO gas generating unit and the photocatalytic reactor unit. The design of reactor was considered according to the geometry of the reactor, the light source and the catalyst. A good degradation has been observed under the conditions of high flow and low concentration in the continuous flow system. Combined with the characteristic of the continuous flow system, the effect of flow rate on the photocatalytic reaction was studied in order to find a suitable flow rate to eliminate the mass transfer problem. The effects of the wavelength and intensity of light source, the initial concentration of the pollutant and the relative...