ABSTRACT
This study investigated the influence of temperature and humidity on the decomposition efficiency of benzene vapor in a packed-bed UV/TiO2 photocatalytical reactor. The packed-bed annular photocatalytical reactor illuminated by a 15-watt ultraviolet lamp was originally designed for this particular study. Pyrex glass beads coated with Degussa P-25 TiO2 (80 % anatase) were packed in the photocatalytical reactor. The operating parameters investigated in this study included reaction temperature (100-260¢J), water vapor concentration (0-1.58¡Ñ104 mg/m3), retention time (3.1-10.3 sec), and inlet benzene concentration (239-478 mg/m3).
Experimental results indicated that the decomposition efficiency of benzene increased with reaction temperature whish was lower than 180¢J, for oxygen content of 21 %, water vapor concentration of 4.69¡Ñ103- 1.58¡Ñ104 mg/m3, and reaction temperature lower then 180¢J. However, the decomposition efficiency of benzene could not be further increased for reaction temperature higher than 180¢J. In addition, the decomposition efficiency of benzene increased with water vapor concentration which was lower than 1.16¡Ñ104 mg/m3. For water vapor concentration higher than 1.16¡Ñ104 mg/m3, the decomposition of benzene could not be further enhanced significantly. In this study, up to 100% of benzene decomposition could be achieved at water vapor concentration of 1.58¡Ñ104 mg/m3 and reaction temperature of 180¢J. Moreover, the decomposition efficiency of benzene increased from 57 to 100% as retention time increased from 3.1 to 10.3 seconds, while decreased from 100 to 65% as benzene concentration increased from 239 to 478 mg/m3.
Modified Langmiur-Hinshewood kinetic model was applied to simulate the photocatalytic decomposition of benzene in the annular packed-bed photocatalytic reactor. The simulation of experimental results was successfully developed to describe the reaction rate of benzene for various reaction temperatures (160-260¢J) during the UV/TiO2 photocatalytical reaction process. Furthermore, reaction rate constant (KLH) and adsorption equilibrium constant (Kc and Kw) were functions of reaction temperature, where can the described by the Arrihenius Law. The rate controlling steps were either photocatalytic reaction on the surface adsorption of reaction products from the surface photocatalysts.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0914101-162546 |
| Date | 14 September 2001 |
| Creators | Hung, Jen-Lin |
| Contributors | Chung-Shin Yuan, Yung-Hsu Hsieh, Chung-Hseun Hung, Jie-Chung Lou |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0914101-162546 |
| Rights | off_campus_withheld, Copyright information available at source archive |
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