Download or read book Selective Catalytic Reduction SCR of Nitric Oxide with Ammonia Using Cu ZSM 5 and Va based Honeycomb Monolith Catalysts written by Saurabh Gupta and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Modeling of Selective Catalytic Reduction SCR of Nitric Oxide with Ammonia Using Four Modern Catalysts written by Giriraj Sharma and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the steady-state performance of zeolite-based Cu-ZSM-5, vanadium based honeycomb monolith catalysts (V), vanadium-titanium based pillared inter layered clay catalyst (V-Ti PLIC) and vanadium-titanium-tungsten-based honeycomb monolith catalysts (V-Ti-W) was investigated in the selective catalytic reduction process (SCR) for NO removal using NH3 in presence of oxygen. The objective is to obtain the expression that would predict the conversion performance of the catalysts for different values of the SCR process parameters, namely temperature, inlet oxygen concentration and inlet ammonia concentration. The NO[subscript]x emission, its formation and control methods are discussed briefly and then the fundamentals of the SCR process are described. Heat transfer based and chemical kinetics based SCR process models are discussed and widely used rate order based model are reviewed. Based on the experimental data, regression analysis was performed that gives an expression for predicting the SCR rate for the complete temperature range and the rate order with respect to inlet oxygen and ammonia concentration. The average activation energy for the SCR process was calculated and optimum operating conditions were determined for each of the catalyst. The applicable operating range for the catalyst depends on the NO conversion as well as on the ammonia slip and the N2O and NO2 emission. The regression analysis was repeated for the applicable range and an expression was obtained that can be used to estimate the catalyst performance. For the Cu-ZSM-5, the best performance was observed for 400°C, 660 ppm inlet ammonia concentration and 0.1% inlet oxygen concentration. For the V based honeycomb monolith catalyst, the best performance was observed for 300°C, 264 ppm inlet ammonia concentration and 3% inlet oxygen concentration. For the V-Ti based PLIC catalyst, the best performance was observed for 350°C, 330 ppm inlet ammonia concentration and 3% inlet oxygen concentration. For the V-Ti-W based honeycomb monolith catalyst, the best performance was observed for 300°C, 330 ppm inlet ammonia concentration and 3% inlet oxygen concentration. The conversion performance of all of these catalysts is satisfactory for the industrial application. At the operating conditions listed above, the N2O emission is less than 20 ppm and the NO2 emission is less than 10 ppm. The results were validated by comparing the findings with the similar work by other research groups. The mechanism of SCR process is discussed for each of the catalyst. The probable reactions are listed and adsorption and desorption process are studied. The various mechanisms proposed by the researchers are discussed briefly. It is concluded that V-Ti-W and Cu-ZSM-5 catalyst are very promising for SCR of NO[subscript]x. The expressions can be used to estimate the conversion performance and can be utilized for optimal design and operation. The expressions relate the SCR rate to the input parameters such as temperature and inlet oxygen and ammonia concentration hence by controlling these parameters desired NO[subscript]x reduction can be achieved with minimal cost and emission.
Download or read book A Superior Fe ZSM 5 Catalyst for Selective Catalytic Reduction SCR of Nitric Oxide with Ammonia written by Gongshin Qi and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selective Catalytic Reduction SCR of Nitric Oxide NO with Ammonia Over Vanadia based and Pillared Interlayer Clay based Catalysts written by Hyuk Jin Oh and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Master s Theses Directories written by and published by . This book was released on 2004 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Education, arts and social sciences, natural and technical sciences in the United States and Canada".
Download or read book Selective Catalytic Reduction SCR of Nitrogen Oxides with Ammonia Over Fe ZSM5 written by Mukundan Devadas and published by . This book was released on 2006 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Selective Catalytic Reduction of Nitric Oxide with Ammonia written by Hans Bosch and published by . This book was released on 1987 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selective Catalytic Reduction of NO with Ammonia Over Nanostructure H ZSM 5 Supported Transition Metal Oxide Catalysts written by A. Niaei and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Temperature Selective Catalytic Reduction SCR of Nitric Oxide with Ammonia written by Lydia Singoredjo and published by . This book was released on 1992 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Role of Ammonia Oxidation in Selective Catalytic Reduction of Nitric Oxide Over Vanadia Based Catalysts written by Mahesh Waman Kumthekar and published by . This book was released on 1992 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Temperature Selective Catalytic Reduction scr of Nitric Oxide Withammonia written by Lydia Singoredjo and published by . This book was released on 1992 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selective Catalytic Reduction of Nitric Oxide by Ammonia Over Iron Exchanged Y Zeolites written by Michael Dimitrios Amiridis and published by . This book was released on 1991 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selective Catalytic Reduction Technology for the Control of Nitrogen Oxide Emissions from Coal Fired Boilers written by Gene Knight and published by DIANE Publishing. This book was released on 2008-08 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Clean Coal Technology Demo. Program (CCTDP) is an effort to demonstrate a new generation of innovative coal utilization processes in a series of facilities built across the country. These projects are carried out on a commercial scale to prove technical feasibility and provide the info. required for future applications. Projects have demonstrated technical options with the potential to meet the needs of energy markets while satisfying environ. requirements. Part of this program is the demo. of technologies designed to reduce emissions of oxides of nitrogen (NOx) from existing coal-fired utility boilers. This report summarizes the status of selective catalytic reduction (SCR) technology for the control of NOx emissions from high-sulfur, coal-fired boilers. Illus.
Download or read book Investigation of the Reaction Network and Catalytic Sites in Selective Catalytic Reduction of Nitric Oxide with Ammonia Over Vanadia Catalysts written by Yeping Cai and published by . This book was released on 1993 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Pressure Drop Catalyst Configuration for the Selective Catalytic Reduction of Nitric Oxide with Ammonia written by Mark Garry and published by . This book was released on 1978 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalyst and Method for Reduction of Nitrogen Oxides written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A Selective Catalytic Reduction (SCR) catalyst was prepared by slurry coating ZSM-5 zeolite onto a cordierite monolith, then subliming an iron salt onto the zeolite, calcining the monolith, and then dipping the monolith either into an aqueous solution of manganese nitrate and cerium nitrate and then calcining, or by similar treatment with separate solutions of manganese nitrate and cerium nitrate. The supported catalyst containing iron, manganese, and cerium showed 80 percent conversion at 113 degrees Celsius of a feed gas containing nitrogen oxides having 4 parts NO to one part NO.sub. 2, about one equivalent ammonia, and excess oxygen; conversion improved to 94 percent at 147 degrees Celsius. N.sub. 2O was not detected (detection limit: 0.6 percent N.sub. 2O).
