Download or read book Catalysts for Low Temperature Conversion of Nitrogen Oxides written by Martin Busch and published by . This book was released on 2015 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalysts for low temperature conversion of nitrogen oxides written by Martin Busch and published by Cuvillier Verlag. This book was released on 2015-06-02 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen oxides are a major threat to human health and largely released by Diesel engines. The present book describes the preparation and characterization of appropriate catalyst systems for low temperature removal (150 - 400°C) and conversion of nitrogen oxides. The presented catalysts include commercially available activated carbon and zeolite supports, infiltrated with iron, copper, manganese and their oxides. The investigated catalysts adsorb and convert nitrogen dioxide almost completely and convert it quickly subsequently into the less toxic nitric oxide and nitrous oxide. Some eventually release nitrogen and oxygen, thus outperforming even the well-known Cu-ZSM-5 catalyst at low temperature. Stickoxide zählen zu den wichtigsten Umweltgiften und werden zu einem großen Anteil durch Dieselmotoren freigesetzt. Dieses Buch beschreibt die Herstellung und Charakterisierung von Katalysatorsysteme für die Niedertemperatur-Umsetzung (150 - 400°C) von Stickoxiden. Zu den vorgestellten Katalysatoren gehören kommerziell verfügbare Aktivkohle und Zeolith-Materialien, welche mit Eisen, Kupfer, Mangan und deren Oxiden infiltriert wurden. Alle untersuchten Katalysatorsysteme absorbieren Stickoxide rasch und setzen diese anschließend fast vollständig in die weit weniger toxischen Gase Stickstoffmonoxid und Distickstoffmonoxid um. Einige der untersuchten Katalysatorsystemen setzen schließlich Sauerstoff und Stickstoff frei und zeigen bei niedrigen Temperaturen sogar eine bessere Performance als der bereits gut bekannte Cu-ZSM-5 Katalysator.
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 Nitrogen oxides NOx why and how they are controlled written by and published by DIANE Publishing. This book was released on 1999 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NOx Trap Catalysts and Technologies written by Luca Lietti and published by Royal Society of Chemistry. This book was released on 2018-06-13 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will be the first to comprehensively present the current research on catalysts used for NOx abatement in lean exhausts.
Download or read book DEVELOPMENT OF IMPROVED CATALYSTS FOR THE SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES WITH HYDROCARBONS written by and published by . This book was released on 2001 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Significant work has been done by the investigators on the cerium oxide-copper oxide based sorbent/catalysts for the combined removal of sulfur and nitrogen oxides from the flue gases of stationary sources. A relatively wide temperature window was established for the use of alumina-supported cerium oxide-copper oxide mixtures as regenerable sorbents for SO2 removal. Preliminary evaluation of these sorbents as catalysts for the selective reduction of NO(subscript x) gave promising results with ammonia, but indicated low selectivity when methane was used as the reductant. Since the replacement of ammonia by another reductant is commercially very attractive, in this project, four research components will be undertaken. The investigation of the reaction mechanism, the first component, will help in the selection of promoters to improve the catalytic activity and selectivity of the sorbents in the SCR with methane. This will result in new catalyst formulations (second component). If this research is successful, the combined SO2-NO(subscript x) removal process based on alumina-supported copper oxide-ceria sorbent/catalysts will become very attractive for commercial applications. The objective of the third component of the project is to develop an alternative SCR process using another inexpensive fuel, residual fuel oil, instead of natural gas. This innovative proposal is based on very scant evidence concerning the good performance of coked catalysts in the selective reduction of NO and if proven to work the process will certainly be commercially viable. The fourth component of the project involves our industrial partner TDA Research, and the objective is to evaluate long-term stability and durability of the prepared sorbent/catalysts. In the first year of the project, the catalysts were investigated by the temperature-programmed reduction (TPR) technique. The results from TPR indicated that the interaction with support appears to promote reduction at lower temperatures. Copper oxide in excess of monolayer coverage reduces at temperatures close to the reduction temperature of the unsupported copper oxide. Increased dispersion increases the support effect. Low activity of ceria in NO reduction may be due to its resistance to reduction at low temperatures.
Download or read book Atlas of Zeolite Framework Types written by Ch. Baerlocher and published by Elsevier. This book was released on 2007-09-12 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zeolite scientists, whether they are working in synthesis, catalysis, characterization or application development, use the Atlas of Zeolite Framework Types as a reference. It describes the main features of all of the confirmed zeolite framework structures, and gives references to the relevant primary structural literature. Since the last edition 34 more framwork types have been approved and are described in this new edition. A further new feature will be that characteristic building units will be listed for each of the framework types.Zeolites and their analogs are used as desiccants, as water softeners, as shape-selective acid catalysts, as molecular sieves, as concentrators of radioactive isotopes, as blood clotting agents, and even as additives to animal feeds. Recently, their suitability as hosts for nanometer spacing of atomic clusters has also been demonstrated. These diverse applications are a reflection of the fascinating structures of these microporous materials. Each time a new zeolite framework structure is reported, it is examined by the Structure Commission of the International Zeolite Association (IZA-SC), and if it is found to be unique and to conform to the IZA-SC's definition of a zeolite, it is assigned a 3-letter framework type code. This code is part of the official IUPAC nomenclature for microporous materials. The Atlas of Zeolite Framework Types is essentially a compilation of data for each of these confirmed framework types. These data include a stereo drawing showing the framework connectivity, features that characterize the idealized framework structure, a list of materials with this framework type, information on the type material that was used to establish the framework type, and stereo drawings of the pore openings of the type material. Clear stereo drawings of each of the framework types Description of the features of the framework type, allowing readers to quickly see if the framework type is suitable to their needs References to isotypic materials, readers can quickly identify related materials and consult the appropriate reference
Download or read book BIFUNCTIONAL CATALYSTS FOR THE SELECTIVE CATALYTIC REDUCTION OF NO BY HYDROCARBONS written by and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Novel bifunctional catalysts combining two active phases, typically Cu-ZSM-5 and a modifier, were prepared and tested for the selective catalytic reduction of nitrogen oxides using propylene in order to overcome the hindering effects of water typically seen for single-phase catalysts such as Cu-ZSM-5. The catalysts were made by typical preparation techniques, but parameters could be varied to influence the catalyst. The physical characterization of the materials showed that the modification phase was added strictly to the external surface of the zeolite without hindering any internal surface area. Chemical characterization by temperature programmed reactions, DRIFTS and x-ray absorption spectroscopy indicated strong interaction between the two phases, primarily producing materials that exhibited lower reduction temperatures. Two improvements in NOx reduction activity (1000 ppm NO, 1000 ppm C3H6, 2% O2, 30,000 hr-1 GHSV) were seen for these catalysts compared with Cu- ZSM-5: a lower temperature of maximum NOx conversion activity (as low at 250 C), and an enhancement of activity when water was present in the system. The use of a second phase provides a way to further tune the properties of the catalyst in order to achieve mechanistic conditions necessary to maximize NOx remediation.
Download or read book Past and Present in DeNOx Catalysis From Molecular Modelling to Chemical Engineering written by Pascal Granger and published by Elsevier. This book was released on 2007-12-15 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers an overview of the state of the art in the field of DeNOx catalysis in order to focus novel orientations, new technological developments, from laboratory to industrial scale. A particular attention has been paid towards the implementation of catalytic processes for minimising NOx emissions either from stationary or mobile sources under lean condition to meet future standard regulations of NOx emissions. In the first part of this book, critical aspects reported in the literature which usually make difficult the achievement of efficient catalytic technologies in those conditions are summarised and analysed in order two separate new perspectives. The second part deals with fundamental aspects at molecular level. A better understanding of the reactions involved under unsteady-state conditions is probably a pre-requisite step for improving the performances of the actual processes or developing original ones. The development of powerful in situ spectroscopic techniques is of fundamental interest for kinetic modelling. Correlations between spectroscopic and kinetic data with those obtained from theoretical calculations are reported. Some illustrations emphasise the fact that these comparisons may help in determining the nature of the catalytic active sites and building predictive tools for simulations under running conditions. The latter part of this book will be illustrated by different practical approaches covering various aspects related to the catalysts preparation and the development of alternative technologies which include industrial considerations. - New technological developments for investigating catalytic reactions in transient conditions (in situ and operando spectroscopic techniques) - Concerted approaches in DeNOx catalysis - How academic aspects (kinetic, in situ spectroscopic measurements) can provide useful information for practical applications - Comparison of different approaches provided by academic and industrial partners
Download or read book Plasma Catalysis written by Annemie Bogaerts and published by MDPI. This book was released on 2019-04-02 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma catalysis is gaining increasing interest for various gas conversion applications, such as CO2 conversion into value-added chemicals and fuels, N2 fixation for the synthesis of NH3 or NOx, methane conversion into higher hydrocarbons or oxygenates. It is also widely used for air pollution control (e.g., VOC remediation). Plasma catalysis allows thermodynamically difficult reactions to proceed at ambient pressure and temperature, due to activation of the gas molecules by energetic electrons created in the plasma. However, plasma is very reactive but not selective, and thus a catalyst is needed to improve the selectivity. In spite of the growing interest in plasma catalysis, the underlying mechanisms of the (possible) synergy between plasma and catalyst are not yet fully understood. Indeed, plasma catalysis is quite complicated, as the plasma will affect the catalyst and vice versa. Moreover, due to the reactive plasma environment, the most suitable catalysts will probably be different from thermal catalysts. More research is needed to better understand the plasma–catalyst interactions, in order to further improve the applications.
Download or read book Nitrogen the Confer N s written by K. van der Hoek and published by Elsevier. This book was released on 2012-12-02 with total page 813 pages. Available in PDF, EPUB and Kindle. Book excerpt: The First International Nitrogen Conference provided an opportunity for researchers and decision-makers to exchange information on environmental pollution by nitrogen compounds on three scales: global, continental/regional and local. The main topics were air, ground water and surface water pollution; emission sources, atmospheric chemistry, deposition processes and effects; disturbance of nitrogen cycles, critical loads and levels; assessments, policy development and evaluation; target groups and abatement techniques; and new approaches leading to an integrated abatement strategy.The peer-reviewed papers from the Conference presented in this volume will provide readers with a comprehensive review of the transport, deposition and impact on ecosystems of nitrogen.
Download or read book Diesel Emissions and Their Control 2nd Edition written by W. Addy Majewski and published by SAE International. This book was released on 2023-12-20 with total page 1135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineers, applied scientists, students, and individuals working to reduceemissions and advance diesel engine technology will find the secondedition of Diesel Emissions and Their Control to be an indispensablereference. Whether readers are at the outset of their learning journey orseeking to deepen their expertise, this comprehensive reference bookcaters to a wide audience.In this substantial update to the 2006 classic, the authors have expandedthe coverage of the latest emission technologies. With the industryevolving rapidly, the book ensures that readers are well-informed aboutthe most recent advances in commercial diesel engines, providing acompetitive edge in their respective fields. The second edition has alsostreamlined the content to focus on the most promising technologies.This book is rooted in the wealth of information available on DieselNet.com, where the “Technology Guide” papers offer in-depth insights. Eachchapter includes links to relevant online materials, granting readers accessto even more expertise and knowledge.The second edition is organized into six parts, providing a structuredjourney through every aspect of diesel engines and emissions control: Part I: A foundational exploration of the diesel engine, combustion, andessential subsystems. Part II: An in-depth look at emission characterization, health andenvironmental impacts, testing methods, and global regulations. Part III: A comprehensive overview of diesel fuels, covering petroleumdiesel, alternative fuels, and engine lubricants. Part IV: An exploration of engine efficiency and emission controltechnologies, from exhaust gas recirculation to engine control. Part V: The latest developments in diesel exhaust aftertreatment,encompassing catalyst technologies and particulate filters. Part VI: A historical journey through the evolution of dieselengine technology, with a focus on heavy-duty engines in the NorthAmerican market. (ISBN 9781468605693, ISBN 9781468605709, ISBN 9781468605716, DOI: 10.4271/9781468605709)
Download or read book Studies on the Reduction of Nitrous Oxide Formation in NOx trap Catalysts written by Javier Mena Casanova and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Current society has become more concerned about being environmentally friendly. Catalytic gas after treatment is one of the solutions adopted to reduce pollutant emissions from a combustion engine. A Three Way NOx Storage Catalytic Converter (TWNSC) is a new development of Daimler AG together with Umicore AG [1]. It consists of a Catalyst with some of the main properties of a Three Way Catalyst (TWC) together with NOx storage capacity (lean-NOx trap). This catalyst is used in Otto direct-injection engines with lean/rich operation mode. This technology can reduce fuel consumption in a range of 10%. During lean engine operation time, high quantities of Nitrogen Oxides (NOx) are generated. In presence of a TWNSC, this NOx can be stored. When the engine changes to rich operating mode, the amount of NOx in exhaust gases decreases become rich of unburned hydrocarbons (HC), hydrogen (H2) and carbon monoxide (CO) that can reduce the NOx stored. However, during NOx reduction, formation of undesired byproducts occur. That is the case of nitrous oxide (N2O) and ammonia (NH3). In this Master thesis, studies on the reduction of nitrous oxide formation in Three Way NOx Storage Catalytic Converter are performed. Studies on N2O formation during catalyst performance have not been widely studied and published. In this master thesis, lean/rich experimentations on two new TWNSC (catalyst A and B) are performed to find conditions in which N2O formation can be reduced. Experiments are performed in a test bench where lean gases are provided by a 1- cylinder-engine and rich gases from synthetic gas mixtures. At the beginning of the master thesis, two preliminary investigations are performed. The first consists of the calculation of Oxygen Storage Capacity (OSC) of a cylindrical sample (25 mm diameter, 30 mm length) of catalyst A and B. The results of the experiment show that catalyst B has less Oxygen Storage Capacity. The experiment consisted on applying a flow of 12,5 l/min of Oxygen (O2) in nitrogen (N2) (0,4% by volume) through the previously reduced sample. An average of 0,3 g./l.cat. less oxygen is stored in catalyst B for temperatures of 300, 350 and 400 oC. At 300oC, catalyst A stores 1,44 g/l.cat. compared to the 0,93 g/l.cat. in catalyst B. The second preliminary investigation consists of determining the temperature in which the Diesel Oxidation Catalyst (DOC) in reactor 1 has to operate. The objective of this DOC is to oxidize the HC and maintain the original NO2/NOx ratio from the engine exhaust gases. During lean mode, gases from a 1-cylinder-engine (Hatz-motor [2]) are used. NOx and HC concentrations are analyzed for a range of temperatures from 150 to 650 oC. It is concluded that a temperature of 620 oC has to be reached in reactor one to get rid of HC and maintain the NO2/NOx ratio of the bypass exhaust gases (2% of NO2 in NOx). After the preliminary investigations, the first objective is getting to know the basic performance of the two different TWNSC. Lean/rich experimentations are performed on both samples A and B at the range of temperatures from 150oC to 450oC. Lean/rich timing is set on 120/15 seconds respectively. In addition, three different rich gas mixtures (lambdas 0,95, 0,9 and 0,82) have been used for the rich mode. Results show that for lambda 0,95 less N2O is generated (0,06 g/l.cat. at 300oC in catalyst A). The minimum N2O detected is at catalyst B at temperatures of 400 and 450oC (0,01 and 0,00 g/l.cat.). The main part of the Master Thesis consists of four different experimentations that have the objective to find any reduction in N2O formation: 1. N2O formation studies with lean/rich experimentations at modified TWNSC catalysts. Instead of the 30 mm sample previously used, two 15 mm samples are used together. Modifications are applied on the first 15 mm sample and consist on five perforations (2 mm diameter) and the introduction of an uncoated central part section. These modifications try to increase reductants velocity during rich mode. Results show a decrease in N2O formation in the experiment with 15 mm uncoated catalyst A together with another 15 mm catalyst A. An average of 2,8 g/l.cat. of N2O reduction is obtained at temperature of 300oC. In addition, an increase of NOx conversion efficiency has been detected: for the same sample and temperature an average increase of 20% NOx performance 2. N2O formation studies with lean/rich experimentations at a combination of catalysts A and B together. It is concluded that the combination of catalyst A and B does not have a beneficial effect on N2O formation. 3. N2O formation studies with lean/rich experimentations with variation of rich time period. The objective is to see if the reduction of rich time period has an effect on N2O formation. 4. Lean/rich experimentations with variation of the lambda during rich period. The objective is to see if a reduction in N2O is obtained with these variations. For low temperatures (150oC and 200oC) a diminution in N2O formation is appreciated (0,05 g/l.cat to 0,04 g./l.cat at 150oC for 30 mm TWNSCA with uncoated section). This Master Thesis represents a base line study for further investigations on N2O formation on TWNSC. Catalyst modifications are a feasible solution for N2O diminution as well as NOx conversion efficiency. These results encourage further experimentations with these current and other new catalyst modifications. Variation of lambda during rich period and variation of the rich time period are variables that can have a relevant role.
Download or read book The Catalytic Chemistry of Nitrogen Oxides written by Richard Klimisch and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the papers and discussions from the sympo!,ium on "The Catalytic Chemistry of Nitrogen Oxides" held at the General Motors Research Laboratories on October 7-8, 1974. This symposium is the eighteenth in the annual series presented by the Research Laboratories. The topics for these symposiums have covered a broad range. Each topic was selected to be of intense current interest and of significant technical importance. There is no question that the subject of the 1974 Symposium satisfies these two criteria. The control of automotive nitrogen oxides has been perhaps the most difficult and controversial area of automotive emissions both in terms of what is necessary and in terms of what is technically feasible. This area has been a source of considerable discussion not only in the technical community but also in governments both in the U. S. and abroad. This meeting brought together scientists working in surface chemistry with engineers working on system design. It also brought together representatives of government, academia and industry. We feel that an important side benefit of the meeting was the improved understanding that was developed between these groups. Participants came from Europe and Japan as well as Canada and the United States. The technical papers spanned the range from fundamental interactions of NO on surfaces through bench scale kinetic and mechanistic studies and ended with catalytic applications. Although the emphasis was on automotive NO removal, stack gas NO x x control was also covered.
Download or read book Advances in Inorganic Chemistry Recent Highlights II written by Rudi van Eldik and published by Academic Press. This book was released on 2022-03-15 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Inorganic Chemistry, Volume 79, the latest release in an esteemed series that highlights new advances in the field of inorganic chemistry, presents new and interesting topics authored by an international field of experts. Provides the authority and expertise of leading contributors from an international board of authors Presents the latest release in the Advances in Inorganic Chemistry series
Download or read book Advances in Applied Chemistry and Industrial Catalysis written by Binoy K. Saikia and published by CRC Press. This book was released on 2022-09-02 with total page 581 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting a collection of papers resulting from the conference on "Applied Chemistry and Industrial Catalysis (ACIC 2021), Qingdao, China, 24-26 December 2021". The theme of the conference was: "Clean Production and High Value Utilization", discussing how to reduce the environmental footprint at the source and produce high value-added end products in chemical manufacturing. The conference brought together scholars from the Chinese government, top universities, business associations, research centers and high-tech enterprises, and was committed to building and enabling a platform for the cooperation among the Chinese government, Chemical industry, and scholars. The goal was to build a bridge between R&D results and the Chemical industry. The conference conducted in-depth exchanges and discussions on relevant topics such as applied chemistry and industrial catalysis aiming to provide an academic and technical communication platform for scholars and engineers engaged in scientific research and engineering practice in the field of chemistry, catalysis and function material. By sharing the research status of scientific research achievements and cutting-edge technologies, it helps scholars and engineers all over the world comprehend the academic development trend and broaden research ideas. So as to strengthen international academic research, academic topics exchange and discussion, and promote the industrialization cooperation of academic achievements.
Download or read book Plasma for Energy and Catalytic Nanomaterials written by Lanbo Di and published by MDPI. This book was released on 2020-12-29 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Special Issue “Plasma for Energy and Catalytic Nanomaterials” highlights the recent progress and advancements in the synthesis and applications of energy and catalytic nanomaterials by plasma. Compared with conventional preparation methods, plasma provides a fast, facile, and environmentally friendly method for synthesizing highly efficient nanomaterials. The synthesized nanomaterials generally show enhanced metal–support interactions, small-sized metal nanoparticles, specific metal structures, and abundant oxygen vacancies. The plasma method allows thermodynamically and dynamically difficult reactions to proceed at low temperatures due to the activation of energetic electrons. Despite the growing interest in plasma for energy and catalytic nanomaterials, the synthesis mechanisms of nanomaterials using plasma still remain obscure due to the complicated physical and chemical reactions that occur during plasma preparation. The Guest Editors and the MDPI staff are therefore pleased to offer this Special Issue to interested reader, including graduate and Ph.D. students, postdoctoral researchers, and the entire community interested in the field of nanomaterials. We share the conviction that the Issue can serve as a useful tool for updating the literature and to aid with the conception of new production and/or research programs. Further dedicated R&D advances are possible based on new instruments and materials under development.
