#13-088

Complete

Date Full Report Received

11/01/2014

Date Abstract Report Received

11/01/2014

Investigation

Institution:
Primary Investigator:

A honeycomb photocatalytic reactor was developed for treating air emissions from swine houses. The reactor was tested in lab and in the field. When residence time was long (8 to 16 seconds), the reactor was able to significantly reduce H2S and NH3 at high concentration levels. When residence time was short (0.018 to 0.042 seconds), the reactor can significantly reduce H2S and NH3 only at very low concentration levels. It was estimated that, for every ppb of H2S concentration in the target air flow, a residence time of 0.04 seconds will be needed for effectively reducing it by half. Similarly, for every ppm of NH3 concentration in the target air flow, a residence time of 0.3 seconds will be needed for effectively reducing it by half. This information can be used for proper sizing of the photocatalytic reactor. The air exhaust from swine buildings usually has high concentration levels as well as high flow rates. In order to treat air emissions from swine buildings, multi stage of reactor will be needed to increase residence time of air flow in the reactor. This can make the size of the reactor unpractical. One alternative solution is to put reactors inside of the swine house where air velocity is much lower than that at the exhaust fan. Another alternative solution is to increase the TiO2 coating surface area per treated air volume by reducing the cell size of the honeycomb filter inside of the reactor, and thus reducing the overall size of the reactor. When using the recommended UV light intensity, the operational electricity cost of the photocatalytic reactor was estimated to be as high as $0.04 per day per pig. However, there is a potential to save electricity cost by using visible light instead of UV. More tests are needed to evaluate performance of the TiO2 coated filter without UV exposure under different residence time.
Contact information: Zifei Liu, 785-532-3587, zifeiliu@ksu.edu