Abstract:

Physical adsorption of volatile organic compounds （VOCs） is a rapid and versatile purification method， which has been widely used in indoor air purifiers. However， due to the limited adsorption amount and the varying of environmental temperature， it often causes secondary pollution to indoor air and seriously threatens people's health during using. The way to avoid secondary pollution through frequent replacement of consumables will not only cause economic losses to consumers， but also bring serious burden to the environment and downstream recycling industry. Therefore， we propose a new VOCs purification method based on Mn-mullite catalyst （YMn₂O₅， YMO）+ozone. The results show that C₃H₆ is completely degraded into carbon dioxide and water at 18 ℃ and 120000 mL/（g·h）. Incense with main components including propylene， polycyclic aromatic hydrocarbons and aliphatic hydrocarbons is used as VOCs source. Under different initial concentrations and relative humidity conditions， the homemade air purifier can rapidly degrade VOCs at 18 ℃， and its clean air delivery rate reaches 75 m³/h. As VOCs initial concentration increases， the time for completing degradation also increases. Besides， the relative humidity changing will also affect the degradation rate of VOCs. When the relative humidity is 40%， the homemade air purifier has the fastest degradation rate. The YMO+O₃ route can effectively degrade VOCs without secondary pollution at room temperature with large humidity variation. Because of the unlimited theoretical lifetime and excellent performance of the catalyst， this technological route is expected to be popular in the next generation of air purifier.

Key words: Volatile organic compounds, Mullite, Room-temperature degradation, Air purifier