Evaluation of an air-cleaning unit having photocatalytic sheets to remove acetaldehyde from indoor air

Abstract

A photocatalytic oxidation (PCO) reactor to which newly developed photocatalytic sheets were applied to decontaminate indoor air was considered in this study. Firstly, the PCO reactor was designed to achieve efficient ultraviolet (UV) irradiation. Then the rate at which acetaldehyde, as a representative indoor air contaminant, was removed by the PCO reactor was calculated using a computational fluid dynamics (CFD) simulation. In this process, some alternatives that achieved higher removal performance using obstacles at the inlet and outlet openings were introduced. The results of the CFD simulation showed that the obstacles installed in the middle of the inlet and outlet openings helped to improve the removal performance of the PCO reactor as the degree of contact by the acetaldehyde on the PCO sheets was increased. Furthermore, the results of these experiments also showed some improvement in removal performance when obstacles were installed. However, the overall experimental performances were far lower than as had been suggested by the CFD simulation, which inferred that the oxidation rate on the surface of the PCO sheets was not 100%, as had been assumed in the CFD simulation. Nevertheless, CFD simulations are assumed to be a good method for selecting the optimal option from many alternative PCO reactors.