An experimental investigation of the urea-water decomposition and selective catalytic reduction (SCR) of nitric oxides with urea using V₂O₅-WO₃-TiO₂ catalyst /
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| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2005]
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| Online Access: | Link to OAK Trust copy |
| Abstract: | Two flow reactor studies, using an electrically heated laminar flow reactor over Vanadia based (V₂O₅-WO₃/TiO₂) honeycomb catalyst, were performed at 1 atm pressure and various temperatures. The experiments were conducted using simulated exhaust gas compositions for different exhaust gases. A quartz tube was used in order to establish inert conditions inside the reactor. The experiments utilized a Fourier transform infrared (FTIR) spectrometer in order to perform both qualitative and quantitative analysis of the reaction products. Urea-water solution decomposition was investigated over V₂O₅-WO₃/TiO₂ catalyst over the entire SCR temperature range using the temperature controlled flow reactor. The solution was preheated and then injected into pure nitrogen (N₂) stream. The decomposition experiments were conducted with a number of oxygen (O₂) compositions (0,1, 10, and 15%) over the temperature range of 227°C to 477°C. The study showed ammonia (NH₃), carbon-dioxide (CO₂) and nitric oxide (NO) as the major products of decomposition along with other products such as nitrous oxide (N₂O) and nitrogen dioxide(NO₂). The selective catalytic reduction (SCR) of nitric oxide (NO) with urea-water solution over V₂O₅-WO₃/TiO₂ catalyst using a laboratory laminar-flow reactor was investigated. Urea-water solution was injected at a temperature higher than the vaporization temperature of water and the flow reactor temperature was varied from 127°C to 477°C. A FTIR spectrometer was used to determine the concentrations of the product species. The major products of SCR reduction were NH₃, NO and CO₂ along with the presenceof other minor products NO₂ and N₂O. NO removal of up to 87% was observed. The aim of the urea-water decomposition experiments was to study the decomposition process as close to the SCR configuration as possible. The aim of the SCR experiments was to delineate the effect of various parameters including reaction temperature and O₂ concentration on the reduction process. The SCR investigation showed that changing parameter values significantly affected the NO removal, the residual NH₃ concentration, the temperature of the maximum NO reduction, and the temperature of complete NH₃ conversion. In the presence of O₂, the reaction temperature for maximum NO reduction was 377°C for [Beta] ratio of 1.0. |
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| Item Description: | "Major Subject: Mechanical Engineering" Title from author supplied metadata (automated record created on Nov. , 09:45:50.) Vita. Abstract. Electronic resource. |
| Physical Description: | 1 online resource. |
| Format: | System requirements: Adobe Acrobat Reader. |
| Bibliography: | Includes bibliographical references. |