Effects of Hydrocarbons and Water Vapor on NOx Using V2O5-WO3/TiO2 Catalyst Reduction in Combination with Nonthermal Plasma
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- 作者：Jae Ok Lee ; Young-Hoon Song ; Min Suk Cha ; Seock Joon Kim
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2007
- 出版时间：August 15, 2007
- 年：2007
- 卷：46
- 期：17
- 页码：5570 - 5575
- 全文大小：161K
- 年卷期：v.46,no.17(August 15, 2007)
- ISSN：1520-5045
文摘
The effects of hydrocarbons and water vapor on a combined deNOx process, which consists of nonthermalplasma oxidation and V2O5-WO3/TiO2 selective catalytic reduction (SCR), are investigated. Test resultsshow that the fast SCR reaction, which needs equimolar amounts of NO and NO2, plays a dominant role inreducing NOx under relatively low-temperature conditions, i.e., 150-200 
C. Under such low-temperatureconditions, the oxidation of NO to NO2 induced by nonthermal plasma is useful in controlling NO2 fractionsin NOx for the fast SCR reaction. The role of the fast SCR reaction, however, decreases when C3H6 is suppliedto the process as simulated hydrocarbons in diesel exhausts. Test results yielded the following conclusions:(1) C3H6 leads to the production of aldehydes in the nonthermal plasma reactor. (2) The NO2 fraction in theSCR reactor decreases as a result of aldehyde production, leading to a diminished role of the SCR reaction.This reduction in NO2 is predominant when water vapor is not added to the test gases. (3) The decreased roleof the fast SCR reaction is recovered when water vapor is present in the treated gases, and the optimal NO2fraction for peak deNOx conversion shifts to higher fractions (greater than 0.5), which should be consideredin treating diesel exhaust.
C. Under such low-temperatureconditions, the oxidation of NO to NO2 induced by nonthermal plasma is useful in controlling NO2 fractionsin NOx for the fast SCR reaction. The role of the fast SCR reaction, however, decreases when C3H6 is suppliedto the process as simulated hydrocarbons in diesel exhausts. Test results yielded the following conclusions:(1) C3H6 leads to the production of aldehydes in the nonthermal plasma reactor. (2) The NO2 fraction in theSCR reactor decreases as a result of aldehyde production, leading to a diminished role of the SCR reaction.This reduction in NO2 is predominant when water vapor is not added to the test gases. (3) The decreased roleof the fast SCR reaction is recovered when water vapor is present in the treated gases, and the optimal NO2fraction for peak deNOx conversion shifts to higher fractions (greater than 0.5), which should be consideredin treating diesel exhaust.