Effect of fly ash on catalytic removal of gaseous dioxins over V{sub 2}O{sub 5}-WO{sub 3} catalyst of a sinter plant
- National Central University, Chungli (Taiwan). Graduate Institute of Environmental Engineering
A PCDD/F (polychlorinated dibenzo-p-dioxin and dibenzofuran)-containing gas stream generating system was developed to investigate the efficiency and effectiveness of V{sub 2}O{sub 5}-WO{sub 3} catalyst for PCDD/F destruction. Catalytic decomposition of PCDD/Fs (simulated gas streams) was evaluated with lab-scale pelletized and plate-type catalyst based on V{sub 2}O{sub 5}-WO{sub 3}/TiO{sub 2} at controlled temperature, space velocity, and inlet PCDD/F concentration. Due to the lower porosity of the pelletized catalyst, PCDD/F destruction efficiencies reach 72.9-83.2% for different levels of inlet PCDD/F concentrations (1.08-3.04 ng-TEQ/Nm{sup 3}) of the gas stream (space velocity: 5000 h-1). As the surface area is increased from 287 m{sup 2}/m{sup 3} (plate-type A) to 550 m{sup 2}/m{sup 3} (plate-type B), the PCDD/F destruction achieved with plate-type catalyst increases from 76.0% to 85.3% at 320{sup o}C (space velocity: 5000 h{sup -1}). In addition, the results of pilot-scale experiment (real flue gases of a sinter plant) indicate that relatively lower PCDD/F destruction efficiencies (62.1-65.7%) were achieved with the plate-type B catalyst as the solid-phase PCDD/F and fly ash passed through the reactor (space velocity: 5000 h{sup -1}). Overall, the lab-scale and pilot-scale experiments indicate that PCDD/F destructions achieved with pelletized and plate-type catalysts strongly depend on the operating temperature of the catalyst. The results also indicate that the presence of fly ash lowers PCDD/F destruction due to significant PCDD/F formation via de novo synthesis at 320{sup o}C. 20 refs., 5 figs., 3 tabs.
- OSTI ID:
- 21240348
- Journal Information:
- Environmental Science and Technology, Vol. 43, Issue 19; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
FLY ASH
REMOVAL
DIOXIN
CATALYSTS
CATALYTIC EFFECTS
DECOMPOSITION
CHLORINATED AROMATIC HYDROCARBONS
BENZOFURANS
VANADIUM OXIDES
TUNGSTEN OXIDES
EFFICIENCY
GASES
SURFACE AREA
SIMULATION
FLUE GAS
PELLETS
CHEMICAL REACTORS
WASTE PRODUCT UTILIZATION
SINTERING
INDUSTRIAL PLANTS