Low temperature oxidation of PCDD/Fs by TiO₂‐based V₂O₅/WO₃ catalyst

Abstract

Catalytic oxidation of vapor phase PCDD/Fs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans) by V 2 O 5 -WO 3 /TiO 2 catalyst at low temperature (1808C) was studied. An innovative PCDD/Fs generating system was designed to supply stable gaseous PCDD/Fs steam with initial concentration of 5.60 ng I-TEQ Nm 23 . The effects of Gas Hourly Space Velocity (GHSV), water vapor content and sulphur-dioxide (SO 2 ) concentration on catalytic oxidation were investigated. The destruction efficiency (DE) reaches a maximum value of 76.4% with a GHSV value of 2000 h 21 .In the presence of water vapor, there are almost no changes for the RE values of PCDD/Fs. Water vapor negatively affects the destruction of PCDD/Fs. However, when 3 vol % of water vapor is introduced into the reaction system, even more PCDD/Fs are destroyed compared with the absence of water vapor. SO 2 can inhibit the destruction of PCDD/Fs by poisoning catalyst. With SO 2 concentration increasing from 0 to 250 ppm, DE value of PCDD/Fs significantly decreases from 68.6% to 38.8%.

The Synergistic Catalysis of Chloroaromatic Organics and NOx over Monolithic Vanadium-Based Catalysts at Low Temperature

“…[11][12][13][14], and rich-pore carriers such as TiO 2 . They exhibited excellent oxidation abilities [15], high selectivity [16], good sulphate resistance [17], and a wide reaction temperature window [18]. Among these active species, Vox, Wox, and MoOx were the most popular active species due to their strong oxidation ability and good poisoning resistance [17][18][19].…”

“…Honeycomb-like, granular, and corrugated forms were the most common and mature monolithic types adopted by the SCR sector [27,28]. The investigations of honeycomb-like catalysts were widely reported [12,15,26,29]. Zhan et al [26] reported that the powder-like catalysts had better degradation efficiency of PCDD/Fs in the stimulated flue gas; however, it was much lower in the practical flue gas than the honeycomb-like catalysts.…”

“…Zhan et al [26] reported that the powder-like catalysts had better degradation efficiency of PCDD/Fs in the stimulated flue gas; however, it was much lower in the practical flue gas than the honeycomb-like catalysts. The excellent removal efficiency (76.4% at 180 • C, 2000 h −1 ) of PCDD/Fs using Vox-Wox/TiO 2 was investigated in the laboratory by Yu et al [15]; another honeycomb Vox-Wox/TiO 2 catalyst showed 95% removal efficiency at 150 • C in the SCR operation [29]. Moreover, the simultaneous removal of Nox and chloroaromatic organic molecules using monolithic catalysts were more concerning.…”

Elimination of PCDD/Fs over Commercial Honeycomb-Like Catalyst of V2O5-MoO3/TiO2 at Low Temperature: From Laboratory Experiments to Field Study

“…Various transient metal oxides, such as MoO 3 , WO 3 , CoO 3 , and CeO 2 , were introduced to solve this problem and enhance catalytic performance. The V 2 O 5 -WO 3 /TiO 2 [4,17,18] and V 2 O 5 -MoO 3 /TiO 2 catalysts [17,19,20] in particular, had a significant market share in the SCR units of MSW incineration plants, due to their excellent performance in poison resistance [21], high removal efficiency [4], and wide reaction temperature window [22]. The V 2 O 5 -WO 3 /TiO 2 catalysts were regarded as the most suitable for coupled de-NOx and PCDD/F destruction systems when the reaction temperature window [7], working life [21], and mercury conversion [4] were considered.…”

“…In addition, catalytic destruction performance and the mechanism of the V 2 O 5 -MoO 3 /TiO 2 catalyst over PCDD/Fs were less reported in the laboratory and industrial conditions, compared to V 2 O 5 -WO 3 /TiO 2 catalysts. The catalysts mentioned [18][19][20]23] were mainly in powder form due to the multiple preparation methods, such as impregnation and sol-gel methods. Monolithic catalysts, such as honeycomb-like forms, were more popular in the industry due to their excellent structural and thermal stabilities, low-pressure drop, and high plugging tolerance [26].…”