Download or read book Development of High Performance SCR catalysts Related to Different Fuel Types DEVCAT written by and published by . This book was released on 2015 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Within the DEVCAT project, high performance high-dust SCR catalysts related to different fuels have been developed, leading to an improved understanding of chemical and physical mechanisms of the reactions at the catalyst. The main focus was put on the development of commercial SCR catalysts for the application in coal-, biomass- and co-combustion derived flue gas with high DeNOx-activity and low SO2/SO3-conversion being able to convert a significantly high share of flue gas elemental mercury into its oxidised form. Oxidised mercury is subsequently absorbed in wet flue gas desulphurisation. Catalysts with different composition including the addition of new metal oxides as well as nano-material and modified geometry have been produced and were tested in micro-, technical-, bench- and full-scale SCR-reactors. The enhanced properties of the newly developed catalysts were demonstrated for all scales consistently. Interactions of relevant pollutants at the catalyst have been identified. Deactivation of newly developed catalysts in flue gas of coaland co-combustion plants was shown to be similar to conventional catalysts. In addition, the regeneration process of heavily deactivated catalysts was studied. A 3D-CFD SCR model was further developed and validated including the processes of deactivation and lifetime behaviour. The model was calibrated with experimental data generated within the project. The model allows the prediction of the distribution of flue gas components from the boiler up to downstream of the catalyst. The widespread and holistic research approach included measurements at lab- and full-scale FGDs in order to identify interactions leading to overall efficient multi-pollutant control.
Download or read book Urea SCR Technology for deNOx After Treatment of Diesel Exhausts written by Isabella Nova and published by Springer Science & Business Media. This book was released on 2014-03-14 with total page 715 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Demonstration of Selective Catalytic Reduction SCR Technology for the Control of Nitrogen Oxide NO Sub X Emissions from High sulfur Coal fired Boilers written by and published by . This book was released on 1991 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor, Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuel performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO2 and SO3. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal.
Download or read book Selective Catalytic Reduction of NOx written by Oliver Kröcher and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The most efficient process to reduce NOx emissions from lean exhaust gases, selective catalytic reduction (SCR) with ammonia, has undergone tremendous development over the past decades. Originally only applied in stationary power plants and industrial installations, SCR systems are now installed in millions of mobile diesel engines, ranging from off-road machineries, to heavy-duty and light-duty trucks and passenger cars, to locomotives and ships. All of these applications involve specific challenges due to tighter emission limits, new internal combustion engine technologies, or alternative fuels. Three review articles and 14 research articles in this book describe recent results and research trends of various aspects of the SCR process. Reaction engineering aspects, such as the proper dosage of ammonia or urea, respectively, are as important as further developments of the different SCR catalysts, by deepening the understanding of their functionality or by systematic improvements of their properties, such as low-temperature activity, selectivity, or poisoning-resistance. Another covered aspect is cost reduction through the use of cheaper base materials for the production is active and stable SCR catalysts. Finally, research efforts are reported to develop SCR processes with different reducing agents, which would open doors to new applications in the future. The range of topics addressed in this book will stimulate the reader's interest as well as provide a valuable source of information for researchers in academia and industry.
Download or read book Catalysts for Upgrading Heavy Petroleum Feeds written by Edward Furimsky and published by Elsevier Science Limited. This book was released on 2007 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mathematical models were reviewed focussing on those which can simulate performance of the commercial operations. Configurations of hydroprocessing reactors were compared in terms of their capability to upgrade various heavy feeds providing that a suitable catalyst was selected. Strategies for regeneration, utilization and disposal of spent hydroprocesing catalysts were evaluated. Potential of the non-conventional hydroprocessing involving soluble/dispersed catalysts and biocatalysts in comparison with conventional methods were assessed to identify issues which prevent commercial utilization of the former.-
Download or read book Passive Ammonia SCR Catalyst System for NOx Abatement from Lean burn Gasoline Engines written by Vitaly Y. Prikhodko and published by . This book was released on 2018 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation summarizes experimental and computational observations from investigations of a selective catalytic reduction (SCR) system for reducing nitrogen oxides (NOx) in lean gasoline engine exhaust based on utilizing ammonia (NH3) generated by a three-way catalyst (TWC) during brief periods of fuel-rich engine operation. NH3 released from the TWC is stored and available to reduce NOx on a downstream SCR catalyst during subsequent periods of lean engine operation. The experimental results include high-speed measurements of transient NH3 formation on the TWC monolith catalysts, as the catalysts were exposed to lean gasoline engine exhaust from a commercial engine. In addition to the experimental investigations, dynamic computational simulations of NH3 generation on the TWC catalyst were implemented to provide more detailed information about NH3 generation on TWCs based on available reaction kinetic mechanisms. Based on the experimental and computational results, estimates of the potential fuel efficiency gains and emissions relevant to simulated drive cycles indicate that passive SCR can potentially achieve significant fuel efficiency benefits while still meeting regulated NOx emissions limits for vehicles powered by lean gasoline engines. However, optimal performance of the system will most likely require development of emission control methods that include accurate models for SCR catalyst NH3 storage and reaction under realistic drive-cycle transients.
Download or read book On the Performance of Oxidation Catalysts and SCR Catalysts in the Presence of Alkali Compounds Representative of Biofuel Contaminants written by Yiquan Xie and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to global lean exhaust gas and new emission regulations, exhaust after-treatment systems of diesel engines are getting more and more sophisticated and comprise a series of catalytic units. In the present work, two of these catalytic systems were studied, Diesel Oxidation Catalysts (DOC) and Selective Catalytic Reduction (SCR) catalysts. Particular attention is paid to their performance in the presence of alkali compounds when bio-diesel is utilized as the alternative fuel.Firstly, this thesis focuses on the catalytic behavior of the Diesel Oxidation Catalyst using different aging characteristics of road mileage in order to improve the efficiency of an ammonia SCR system on an after-treatment line composed by a DOC + DPF + SCR. The studied catalyst is a commercial diesel oxidation catalyst (Pt/Pd/Al2O3) provided by Continental. Hydrothermal aging under different conditions on carrots of monolith were performed. Also studied in the monolith form over the commercial DOC, the influence of the addition of different alkali metal species (K and Na) on the commercial DOC through catalytic tests performed on this structured catalyst under multicomponent (C3H6 / CO / NO / NO2) co-feeding conditions was explored. Aiming at investigating the effects of the presence of different alkali metal species on the DOC at the level of active phase, homemade bimetallic DOC is prepared and then different alkali metal species incorporated. Finally, encouraged by the evident influence of alkali compounds on DOCs, their impacts on the downstream SCR catalysts are also studied in this thesis. The studied SCR catalyst is a commercial V2O5-based catalyst provided by UMICORE company.
Download or read book Demonstration of Selective Catalytic Reduction SCR Technology for the Control of Nitrogen Oxide NO subscript X Emissions from High sulfur Coal fired Boilers Quarterly Report No 4 April June 1991 written by and published by . This book was released on 1991 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor, Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuel performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO2 and SO3. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal.
Download or read book Validation of a Standardized Measuring Journal for Calibration of Exhaust Gas After Treatment Catalysts Investigation of the Effect of Hydrocarbon Species on SCR Catalyst Behaviour written by Juan Miralles Munita and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In Research & Development, the simulation of the aftertreatment systems has become a fundamental part in the development process for the automobile industry. It is normal then to study individually every aftertreatment technology in order to create simulation models for these technologies such as Selective Catalytic Reduction (SCR), Diesel Oxidation Catalyst (DOC) or Diesel Particle Filter (DPF). For helping the creation of these models, dedicated experiments are carried out. These kinetic experiments must be designed and well-defined such that they provide the necessary information in a reproducible way at minimal time and costs. In the first part of the work and in order to facilitate measurements with long SDPF specimens, a reactor with a new oven design has been characterized. Its thermal behaviour and the absence of unwanted reactions of the bare reactor (without catalyst) have been checked. In a previous work, dedicated kinetic measurement procedures for the SCR calibration process were determined and optimized on a synthetic gas test rig. The optimal settings and procedures were programed in the test rig control software. In the second part of this work, several measurements based on these optimal procedures have been carried out on the test rig with a state-of-the-art Cu-Ze SCR to investigate the influence of several types of HCs on the SCR behaviour. The alternative of the NO2/NOx ratio step concept was used for the NOx conversion study of the SCR catalyst. It has been seen that the presence during the experiment of different HC species such as C3H6 and C2H2 had an negative effect in the NOx reduction, and for other HC species as C3H8 the effect was practically inexistent. The results of this work will help to better understand the behaviour of SCR catalysts and SDPF filters for future investigations.
Download or read book Demonstration of Selective Catalytic Reduction SCR Technology for the Control of Nitrogen Oxide NO subscript X Emissions from High sulfur Coal fired Boilers Quarterly Report No 8 April June 1992 written by and published by . This book was released on 1992 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO(subscript x)) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO(subscript x) to convert it to nitrogen and water vapor. Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuels. (2) performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO2 and SO3. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur U.S. coal.
