COMPARATIVE STUDY OF N2O FORMATION DURING THE SELECTIVE CATALYTIC REDUCTION OF NO BY NH3 IN THE PRESENCE AND ABSENCE OF O2 CONDITIONS

COMPARATIVE STUDY OF N2O FORMATION DURING THE SELECTIVE CATALYTIC REDUCTION OF NO BY NH3 IN THE PRESENCE AND ABSENCE OF O2 CONDITIONS PDF Author: Archareeyaporn Ruengthawornkul
Publisher:
ISBN:
Category : Catalysts
Languages : en
Pages : 158

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The present work investigates the formation of N2O during the SCR of NO with NH3 over V2O5/TiO2, WO3/TiO2, MoO3/TiO2, V2O5-WO3/TiO2 and V2O5-MoO3/TiO2 catalysts. All catalysts are characterized by using BET surface area measurement, XRD, FT-IR, NH3-TPD, Pyridine adsorption, and ICP-OES. The effluent gas in the SCR experimental contains 120 ppm NO, 120 ppm NH3, 30 ppm SO2, 15 vol% O2, and 15 vol% H2O, balanced with N2. The reaction is carried out in the reaction temperature 120-450°C. A gas chromatograph Shimadzu GC-2014 equipped with an ECD is used to measure the amount of NO and N2O in the effluent gas. The effect of SO2 on the formation of N2O during the SCR process over the catalysts is tested by removing SO2 from the feed gas. The effect of O2 on the formation of N2O during the SCR process over the catalysts is tested by removing O2 from the feed gas. The results show that O2 is necessary for the SCR of NO by NH3 over WO3/TiO2 and V2O5-WO3/TiO2 catalysts. The SCR of NO over V2O5/TiO2, MoO3/TiO2 and V2O5-MoO3/TiO2 catalysts can proceed in the absence of O2, but at a higher reaction temperature with a large amount of N2O form. The results demonstrate that lattice oxygen (O-2) of V2O5/TiO2, MoO3/TiO2 and V2O5-MoO3/TiO2 catalysts can participate the SCR process at the high reaction temperature. O-2 on MoO3/TiO2 and V2O5-MoO3/TiO2 catalysts is participate to increase N2O formed from the SCR process. N2O is formed from the reaction between NH3 and O2 rather than NO.

COMPARATIVE STUDY OF N2O FORMATION DURING THE SELECTIVE CATALYTIC REDUCTION OF NO BY NH3 IN THE PRESENCE AND ABSENCE OF O2 CONDITIONS

COMPARATIVE STUDY OF N2O FORMATION DURING THE SELECTIVE CATALYTIC REDUCTION OF NO BY NH3 IN THE PRESENCE AND ABSENCE OF O2 CONDITIONS PDF Author: Archareeyaporn Ruengthawornkul
Publisher:
ISBN:
Category : Catalysts
Languages : en
Pages : 158

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Book Description
The present work investigates the formation of N2O during the SCR of NO with NH3 over V2O5/TiO2, WO3/TiO2, MoO3/TiO2, V2O5-WO3/TiO2 and V2O5-MoO3/TiO2 catalysts. All catalysts are characterized by using BET surface area measurement, XRD, FT-IR, NH3-TPD, Pyridine adsorption, and ICP-OES. The effluent gas in the SCR experimental contains 120 ppm NO, 120 ppm NH3, 30 ppm SO2, 15 vol% O2, and 15 vol% H2O, balanced with N2. The reaction is carried out in the reaction temperature 120-450°C. A gas chromatograph Shimadzu GC-2014 equipped with an ECD is used to measure the amount of NO and N2O in the effluent gas. The effect of SO2 on the formation of N2O during the SCR process over the catalysts is tested by removing SO2 from the feed gas. The effect of O2 on the formation of N2O during the SCR process over the catalysts is tested by removing O2 from the feed gas. The results show that O2 is necessary for the SCR of NO by NH3 over WO3/TiO2 and V2O5-WO3/TiO2 catalysts. The SCR of NO over V2O5/TiO2, MoO3/TiO2 and V2O5-MoO3/TiO2 catalysts can proceed in the absence of O2, but at a higher reaction temperature with a large amount of N2O form. The results demonstrate that lattice oxygen (O-2) of V2O5/TiO2, MoO3/TiO2 and V2O5-MoO3/TiO2 catalysts can participate the SCR process at the high reaction temperature. O-2 on MoO3/TiO2 and V2O5-MoO3/TiO2 catalysts is participate to increase N2O formed from the SCR process. N2O is formed from the reaction between NH3 and O2 rather than NO.

The Origin of N2O Formation in the Selective Catalytic Reduction of NOx by NH3 in O2 Rich Atmosphere on Cu-Faujasite Catalysts

The Origin of N2O Formation in the Selective Catalytic Reduction of NOx by NH3 in O2 Rich Atmosphere on Cu-Faujasite Catalysts PDF Author: Stephane Kieger
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages : 2

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Selective Catalytic Reduction of NOx

Selective Catalytic Reduction of NOx PDF Author: Oliver Kröcher
Publisher: MDPI
ISBN: 3038973645
Category : Science
Languages : en
Pages : 281

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This book is a printed edition of the Special Issue "Selective Catalytic Reduction of NOx" that was published in Catalysts

Nitrogen oxides (NOx) why and how they are controlled

Nitrogen oxides (NOx) why and how they are controlled PDF Author:
Publisher: DIANE Publishing
ISBN: 1428902805
Category :
Languages : en
Pages : 57

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Selective Catalytic Reduction (SCR) of Nitric Oxide (NO) with Ammonia Over Vanadia-based and Pillared Interlayer Clay-based Catalysts

Selective Catalytic Reduction (SCR) of Nitric Oxide (NO) with Ammonia Over Vanadia-based and Pillared Interlayer Clay-based Catalysts PDF Author: Hyuk Jin Oh
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The selective catalytic reduction (SCR) of nitric oxide (NO) with ammonia over vanadia-based (V2O5-WO3/TiO2) and pillared interlayer clay-based (V2O5/Ti-PILC) monolithic honeycomb catalysts using a laboratory laminar-flow reactor was investigated. The experiments used a number of gas compositions to simulate different combustion gases. A Fourier transform infrared (FTIR) spectrometer was used to determine the concentrations of the product species. The major products were nitric oxide (NO), ammonia (NH3), nitrous oxide (N2O), and nitrogen dioxide (NO2). The aim was to delineate the effect of various parameters including reaction temperature, oxygen concentration, NH3-to-NO ratio, space velocity, heating area, catalyst arrangement, and vanadium coating on the removal of nitric oxide. The investigation showed that the change of the parameters significantly affected the removals of NO and NH3 species, the residual NH3 concentration (or NH3 slip), the temperature of the maximum NO reduction, and the temperature of complete NH3 conversion. The reaction temperature was increased from the ambient temperature (25°C) to 450°C. For both catalysts, high NO and NH3 removals were obtained in the presence of a small amount of oxygen, but no significant influence was observed from 0.1 to 3.0% O2. An increase in NH3-to-NO ratio increased NO reduction but decreased NH3 conversions. For V2O5-WO3/TiO2, the decrease of space velocity increased NO and NH3 removals and broadened the active temperature window (based on NO> 88% and NH3> 87%) about 50°C. An increase in heating area decreased the reaction temperature of the maximum NO reduction from 350 to 300 ʻC, and caused the active reaction temperature window (between 250 and 400 ʻC) to shift toward 50 ʻC lower reaction temperatures (between 200 and 350°C). The change of catalyst arrangements resulted slight improvement for NO and NH3 removals, therefore, the change might contribute to more gas removals. The catalyst with extra vanadium coating showed higher NO reductions and NH3 conversions than the catalyst without the extra vanadium coating.

Urea-SCR Technology for deNOx After Treatment of Diesel Exhausts

Urea-SCR Technology for deNOx After Treatment of Diesel Exhausts PDF Author: Isabella Nova
Publisher: Springer Science & Business Media
ISBN: 1489980717
Category : Science
Languages : en
Pages : 715

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Book Description
Urea-SCR Technology for deNOx After Treatment of Diesel Exhausts presents a complete overview of the selective catalytic reduction of NOx by ammonia/urea. The book starts with an illustration of the technology in the framework of the current context (legislation, market, system configurations), covers the fundamental aspects of the SCR process (catalysts, chemistry, mechanism, kinetics) and analyzes its application to useful topics such as modeling of full scale monolith catalysts, control aspects, ammonia injections systems and integration with other devices for combined removal of pollutants.

Air Pollution Abstracts

Air Pollution Abstracts PDF Author:
Publisher:
ISBN:
Category : Air
Languages : en
Pages : 670

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Selective Catalytic Reduction of Nitric Oxide by Ammonia Over Iron Exchanged Y Zeolites

Selective Catalytic Reduction of Nitric Oxide by Ammonia Over Iron Exchanged Y Zeolites PDF Author: Michael Dimitrios Amiridis
Publisher:
ISBN:
Category :
Languages : en
Pages : 684

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Selective Catalytic Reduction (SCR) of Nitric Oxide with Ammonia Using Cu-ZSM-5 and Va-based Honeycomb Monolith Catalysts

Selective Catalytic Reduction (SCR) of Nitric Oxide with Ammonia Using Cu-ZSM-5 and Va-based Honeycomb Monolith Catalysts PDF Author: Saurabh Gupta
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
In this work, the steady-state performance of zeolite-based (Cu-ZSM-5) and vanadium-based honeycomb monolith catalysts was investigated in the selective catalytic reduction process (SCR) for NO removal using NH3. The aim was to delineate the effect of various parameters including pretreatment of the catalyst sample with H2, NH3-to-NO ratio, inlet oxygen concentration, and space velocity. The concentrations of the species (e.g. NO, NH3, and others) were determined using a Fourier Transform Infrared (FTIR) spectrometer. The temperature was varied from ambient (25 C) to 500 C. The investigation showed that all of the above parameters (except pre-treatment with H2) significantly affected the peak NO reduction, the temperature at which peak NO reduction occurred, and residual ammonia left at higher temperatures (also known as 'NH3 slip'). Depending upon the particular values of the parameters, a peak NO reduction of around 90% was obtained for both the catalysts. However, an accompanied generation of N2O and NO2 species was observed as well, being much higher for the vanadium-based catalyst than for the Cu-ZSM-5 catalyst. For both catalysts, the peak NO reduction decreased with an increase in space velocity, and did not change significantly with an increase in oxygen concentration. The temperatures at which peak NO reduction and complete NH3 removal occurred increased with an increase in space velocity but decreased with an increase in oxygen concentration. The presence of more ammonia at the inlet (i.e. higher NH3-to-NO ratio) improved the peak NO reduction but simultaneously resulted in an increase in residual ammonia. Pretreatment of the catalyst sample with H2 (performed only for the Cu-ZSM-5 catalyst) did not produce any perceivable difference in any of the results for the conditions of these experiments.

The Formation and Role of NO2 During the Selective Catalytic Reduction of NO by Methane in the Presence of Excess Oxygen Over Cation- Exchanged Zeolites

The Formation and Role of NO2 During the Selective Catalytic Reduction of NO by Methane in the Presence of Excess Oxygen Over Cation- Exchanged Zeolites PDF Author: Mei-Hui Ho
Publisher:
ISBN:
Category :
Languages : en
Pages : 248

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