Kinetics of Selective Catalytic NOx Reduction in a Novel Gas-Particle Filter Reactor (Catalytic Filter Element and Sponge Insert)
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- 作者：Sebastian Zü ; rcher ; Marius Hackel ; Georg Schaub
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2008
- 出版时间：March 5, 2008
- 年：2008
- 卷：47
- 期：5
- 页码：1435 - 1442
- 全文大小：350K
- 年卷期：v.47,no.5(March 5, 2008)
- ISSN：1520-5045
文摘
Multifunctional reactors for the simultaneous filtration and selective catalytic reduction (SCR) of NOx inhigh-temperature gas cleaning are of industrial interest. Two configurations have been investigated, using aV2O5/WO3/TiO2-based catalyst: in one configuration, ceramic candle material can be impregnated with acatalyst providing, both efficient particle separation and high activity for the removal of NOx, whereas, in theother configuration, ceramic sponges that have been impregnated with a catalyst are placed inside a ceramiccandle. Sponges, which, in the literature, are most commonly called open-cell foams, are highly porousstructures and recently have been investigated as novel catalyst supports. For characterization of these catalystconfigurations, a kinetic analysis has been performed, supported by additional experimental data obtained ina fixed-bed reactor. The inlet concentrations, modified residence time, and temperature were varied to validatea mathematical reactor model, based on known selective catalytic reduction (SCR) kinetics that have beenderived from the literature. Both novel catalyst configurations were tested at common filtration surface velocities(usurf = 1-4 cm/s) and temperatures (150-380 
C), such as those commonly used in honeycomb DeNOxreactors. For the discussion of the possible effects that occur in the structures, new kinetic parameters weredetermined via a minimization of squared errors. Because of low gas velocity inside the ceramic structuresespecially, backmixing was taken into account, using a dispersion model. The highest conversion valueswere observed at 300 C in all configurations but were generally lower in the multifunctional reactorconfigurations. The NO conversion decreased at higher temperatures, because of NH3 oxidation with oxygen.The validated model allows case studies about applications of multifunctional reactors in flue gas cleaningand provides insight into the characteristic sponge properties and their potential in heterogeneous catalysis.
C), such as those commonly used in honeycomb DeNOxreactors. For the discussion of the possible effects that occur in the structures, new kinetic parameters weredetermined via a minimization of squared errors. Because of low gas velocity inside the ceramic structuresespecially, backmixing was taken into account, using a dispersion model. The highest conversion valueswere observed at 300 C in all configurations but were generally lower in the multifunctional reactorconfigurations. The NO conversion decreased at higher temperatures, because of NH3 oxidation with oxygen.The validated model allows case studies about applications of multifunctional reactors in flue gas cleaningand provides insight into the characteristic sponge properties and their potential in heterogeneous catalysis.