Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
248360 | Building and Environment | 2013 | 10 Pages |
•PCO performance was investigated for different types of lamps and catalyst substrates.•Generated by-products depend on the presence of ozone and operational conditions.•VUV lamps promote photocatalytic oxidation of ethanol compared to UVC lamps.•Acetaldehyde, formaldehyde and propionaldehyde are formed by both UVC and VUV lamps.•Crotonaldehyde is generated only in the presence of VUV lamps and ozone.
Ultraviolet photocatalytic oxidation (UV-PCO) is regarded as one of the promising technologies for air purification. Previous studies on UV-PCO of ethanol were performed in an ideal bench top reactors. However, this research is focused on UV-PCO of ethanol in full-scale open test rig which closely resembles the real application of this technology. Ethanol mineralization was investigated under several conditions including two types of UV-lamps (UVC and VUV) for two different photocatalysts under varied concentrations, airflow rate and relative humidity. In each case, removal efficiency and by-products yield were compared. Furthermore, possible mechanism for by-product formation is presented. Experimental results show that acetaldehyde and formaldehyde are the main by-products of ethanol. VUV lamps increase photocatalytic oxidation of ethanol compared to UVC lamps. The increase of relative humidity decreases UV-PCO of ethanol using both VUV and UVC lamps; however, the yield of by-products in the presence of VUV lamps increases while it decreases in the presence of UVC lamps. Higher flow rate results lower removal efficiency and consequently formation of less by-products. Improvement of reaction section by increasing the number of reactors leads to higher ethanol removal efficiency, less partial oxidation, lower amount of by-products and the complete mineralization of acetaldehyde.