Download or read book Experimental Investigation of a Dual catalyst for the Selective Catalytic Reduction of Nitric Oxide with Ammonia written by Frank G. Medros and published by . This book was released on 1987 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selective Catalytic Reduction of NOx written by Oliver Kröcher and published by MDPI. This book was released on 2018-12-14 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Selective Catalytic Reduction of NOx" that was published in Catalysts
Download or read book An Experimental Investigation of the Urea water Decomposition and Selective Catalytic Reduction SCR of Nitric Oxides with Urea Using V2O5 WO3 TiO2 Catalyst written by Jasmeet Singh Johar and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
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 Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1 957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 32 (thesis year 1987) a total of 12,483 theses titles from 22 Canadian and 176 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 32 reports theses submitted in 1987, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.
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 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 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 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 A Study of the Oxidation of Ammonia and the Selective Catalytic Reduction of Nitric Oxide by Ammonia in the Presence of Oxygen on an Iron Oxide chromium Oxide vanadium Pentoxide Catalyst Supported on Alumina written by Wing Cheong Wong and published by . This book was released on 1979 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of the Kinetics of No Reduction by Ammonia on an Automotive Catalyst written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As lean-burn engines are being introduced in the United States, both advantages and disadvantages arise. Lean-burn engines can operate at a high efficiency, and are developed for a wide range of power supplies. Unfortunately, due to the low temperature at which these engines operate, NO[subscript x] formation becomes an issue. Forthcoming legislation pertaining to heavy-duty lean-burn engines aimed at reducing both particulate matter emissions and emissions of nitric oxides has brought about a need for a better method for reducing NO[subscript x] from lean exhaust gases at moderate temperatures. It is generally accepted that current fuel treatment processes alone will be unable to accommodate emission standards proposed for upcoming years. While the current 3-way catalyst is ineffective in reducing NO[subscript x] under lean conditions, many new strategies are being developed. The Lean NO[subscript x] Catalyst (LNC), Lean NO[subscript x] Trap (LNT), and Selective Catalytic Reduction (SCR) catalyst are all viable methods with research underway. Currently, the selective catalytic reduction (SCR) of nitrogen oxides by N-containing reducing agents is one of the most powerful methods for accomplishing the removal of NO[subscript x] from an exhaust stream. This technology has been in place in steady state power plants, but has yet to be fully implemented in mobile engines. This is due in part to the problems encountered in the automated control of ammonia addition to the exhaust gas. In steady state operation, a relatively constant amount of NO[subscript x] is produced over a given amount of time. Thus, to provide a stoichiometric amount of ammonia only the steady state concentration of NO[subscript x] must be known. In an automotive application the NO[subscript x] produced is not constant and the addition of ammonia must vary accordingly. The purpose of this thesis is to explore the SCR process of the reaction between NO and NH3 through an experimental matrix and also through a kinetic study extracted from the results. These results are used in a simple theoretical model of the SCR reaction. The use of NO as the only form of NO[subscript x] allows for the kinetics of the NO reaction to be studied separately from the NO2 kinetics. This will be a first step in understanding the overall SCR process involving both NO and NO2. The SCR process for the reaction between NO and NH3, while understood on a global scale, is still under debate at the elementary level. It is currently thought that the reaction occurs according to an Eley-Rideal mechanism, where strongly absorbed ammonia reacts with weakly absorbed or gas phase NO to produce nitrogen and water. It is generally accepted that this reaction proceeds in first order with respect to nitric oxide and zero order with respect to ammonia and oxygen.
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 Development of Catalysts for the Selective Reduction of Nitric Oxide by Ammonia written by Curtis N. Eng and published by . This book was released on 1977 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Selective Catalytic Reduction of Nitric Oxide with Ammonia written by Franciscus Johannes Josephus Gerardus Janssen and published by . This book was released on 1987 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 1830 1831 written by and published by . This book was released on 1834 with total page 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 Superior Catalysts for Selective Catalytic Reduction of Nitric Oxide Quarterly Technical Progress Report January 1 1995 March 31 1995 written by and published by . This book was released on 1995 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: During this quarter, progress was made on the following tasks: TPD techniques were employed to study the reaction mechanism of the selective catalytic reduction of nitrogen oxide with ammonia over iron oxide pillared clay catalyst; and a sulfur dioxide resistant iron oxide/titanium oxide catalyst was developed.
