Using Low Carbon Numbers Saturated Hydrocarbons Gas for Reduction of Nitrogen Oxide by Zero-Valent Iron Fluidized Bed

• Main Authors: Wen-Hong Tseng, 曾文宏
• Other Authors: 陳孝行
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/t42w23

碩士 === 國立臺北科技大學 === 環境規劃與管理研究所 === 95 === This research is to use Hexane gas for reduction of nitrogen oxide by zero-valent iron fluidized bed reactor. Five different parameters: temperature (623, 673, 723 and 773K), Hexane concentrations (0, 1000, 1500 and 2000ppm), ZVI dosages (0.5, 1.0 and 2.0g), flux (0.4, 0.6 and 0.8 L/cm2-min), and O2 concentrations (3, 5 and 7%) were tested in the fluidized bed reactor to study 400ppm of NO. Under the ZVI dosages of 2.0g at flux 0.6 L/cm2-min at the temperature 773K, when the Hexane concentration is increased to 1000ppm from 0, the capacity of ZVI for De-NO decreases to 25.49 from 39.42 mg-NO/g-Fe. The capacity of ZVI for De-NO is the same when Hexane concentration is 1000 ,1500 or 2000ppm. When temperature is increased from 623K to 773K with 1500ppm Hexane, the capacity of ZVI for De-NO increased to 26.04 from 2.01 mg-NO/g-Fe. As the results, the increase of temperature can make the capacity of ZVI for De-NO to increase, but the increase of Hexane concentration will not affect the capacity. The capacity of ZVI for De-NO and breakthrough time can be affected by both ZVI dosage and flux variation. A parameter ZVI weight/flux (WFe/F) was developed to assess the breakthrough time of NO removed by ZVI and higher breakthrough time can be measured from higher WFe/F value. XRD and GC/MS were conducted to analyze the crystal structure and reacted gas. Several elements were determined from the spectrum：Hexane, Fe0(ZVI), Fe2C, FeCO3, Fe2O3, and Fe3O4. There are three chemical mechanisms among ZVI, nitric oxide, and Hexane, (1) 3Fe＋4NO→ Fe3O4＋2N2 (2)4Fe3O4＋2NO→ 6Fe2O3＋N2 (3)3Fe3O4＋C6H14→4Fe2C＋FeCO3＋7H2O＋CO2. Last, compared with removal efficiency of CO/ZVI/NO and Hexane/ZVI/NO, we found that the ecffectiveness of removal efficiency of CO was better.