Download or read book The Calculation of Temperature Gradients in a Fixed Bed Catalytic Converter with Fluid Phase Reactants and Products written by Jack McLeod Andrews and published by . This book was released on 1948 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two phase two dimensional models of fixed bed catalytic reacto written by Ali Morteza Samsam Bekhtiari and published by . This book was released on 1972 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methods for Monitoring and Diagnosing the Efficiency of Catalytic Converters written by M. Sideris and published by Elsevier. This book was released on 1998-06-19 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dramatic evolution of catalytic converters in the last thirty years was a result of a need worldwide to reduce pollution created by the exhaust gases of internal combustion engines. Environmental concerns have led American, Japanese and European Union (EU) legislation to pose continuously stricter emission limits for petrol engines in the last decades. The catalytic converter has become the most important means of exhaust treatment to achieve the desired emission limits. The international legislation has also created a need for a regular assessment of the efficiency of the catalytic converter in order to detect a deterioration of its conversion efficiency as soon as this deterioration takes place. The assessment of conversion efficiency of a catalytic converter can take place during normal driving of a vehicle (on-board diagnosis or OBD) or in a workshop by specialized technicians. The most important methods nowadays are the OBD methods. The evolution of methods concerned with OBD and non-OBD monitoring and diagnosing of efficiency of catalytic converters of internal combustion engines is described based on patents and published patent applications. Non-patent references are also used. The basic principles of modern catalytic converters are described in an extensive Introduction, where the importance of monitoring and diagnosing the efficiency of catalytic converters is demonstrated. The book is divided into four parts. The first part describes methods involving the use of oxygen or air/fuel exhaust gas sensors to determine the oxygen storage capacity of a catalytic converter. The second part describes methods involving the use of temperature sensors to determine the exothermic reaction capacity of a catalytic converter. The third part describes all other methods existing in patent literature that monitor and diagnose the efficiency of catalytic converters. The great majority of the methods of the third part involves exhaust gas concentration measurements. The fourth part comprises a general discussion of all methods described. In the beginning of each part, a short introduction is given to explain the problem that the methods attempt to solve. The methods in each part are presented in chronological order per patent applicant. This helps to evaluate how the patent applicant has improved his methods over time. A patent number index with information about the patent applicants, inventors, priorities and patent-families, an inventor index, a company index and a subject index can be found at the end of the book.
Download or read book New and Future Developments in Catalysis written by Andrzej Kołodziej and published by Elsevier Inc. Chapters. This book was released on 2013-07-17 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CFD Simulation and Experiment of Catalyst Deactivation and Heat Transfer in a Low N Fixed bed Reactor written by Mohsen Behnam and published by . This book was released on 2011 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Modeling of fluid flow, heat transfer and reaction in fixed beds is an essential part of their design. This is especially critical for highly endothermic reactions in low tube-to-particle diameter ratio (N) tubes, such as methane steam reforming (MSR) and alkane dehydrogenation as two important commercial reactions. The modeling of fixed bed reaction is available in literatures with lots of assumptions. However, there is a need for implementing the reaction conditions with diffusion aspects on a real fixed bed reactor without assuming any pseudo conditions. Computational fluid dynamics (CFD) has been found as a suitable tool by many researchers to simulate fixed beds. CFD can simulate complex geometry of randomly-packed tubes, and provides us with more fundamental understanding of the transport and reaction phenomena in reactor tubes. CFD can be used to obtain detailed three-dimensional velocity, species and temperature fields that are needed to improve engineering approaches. Previously, the geometry of 120-degree wall segment (WS) of the whole reactor tube has been studied in our group. Previous works have introduced the coupling of gas flow and resolved species and temperature gradients inside pellets by CFD for methane steam reforming (MSR) and propane dehydrogenation (PDH) without considering deactivation. The deactivation of catalysts due to carbon formation is an important problem in industry, such as steam reforming and the catalytic dehydrogenation of alkanes, which are both strongly endothermic reactions. Many researches were carried out to study the effect of carbon formation and catalyst deactivation on the reactor performance. The local carbon deposition on catalysts can cause particle breakage and strongly decrease reaction rates. Catalyst deactivation in heated tubes removes the heat sink and can result in local hot spots that weaken the reactor tube. This is particularly a problem for a low tube-to-particle diameter ratio fixed bed reactor. A 3D resolved CFD model simulation was used to study the local details of carbon deposition in which the reactions and deactivation take place inside the catalytic solid particles. CFD simulations of flow, heat transfer, diffusion and reaction were carried out using the commercial CFD code FLUENT/ANSYS 6.3 in a 3D 120-degree periodic wall segment with N=4. The mesh used boundary layer prism cells at both the inside and outside particle surfaces and at the tube wall. These reactions were represented in the solid particles using user-defined scalars to mimic species transport and reaction, with user-defined functions supplying reaction rates. Diffusion in the particles was modeled by Fick's law using an effective diffusivity, given by Hite and Jackson's approximation of the Dusty Gas Model. The transient developments of particle internal gradients and carbon accumulation have been studied for the early stages of deactivation. Carbon concentration is initially strongest close to the surface and in the high temperature regions of the catalysts and affected by the wall heat flux. Deactivation of the endothermic reactions causes a slow increase in the average catalyst temperature. The second stage of the research was the verification of our CFD reaction model with experimental data under reacting conditions. The highly endothermic commercial methane steam reforming (MSR) reaction was studied experimentally in a fixed bed reactor. The temperature contributions inside catalyst particles were measured. The MSR reaction showed strong effects on the temperature profile along the reactor. Then, a CFD model was used to predict temperature profiles under MSR reaction conditions. Comparison of CFD and experimental data showed very good qualitative as well as quantitative agreement for temperature inside catalyst particles at different inlet gas temperatures. The last stage was to develop a fundamental energy equation without introducing new adjustable parameters to study heat transfer in fixed beds. In the past, many researchers have been carried out to simulate the heat transfer in fixed bed reactors by using k[subscript r] (effective thermal conductivity) and h[subscript w] (heat transfer coefficient). But the classical model with k[subscript r] and h[subscript w] cannot give a correct T(r) near tube wall, where deactivation is strongest. Therefore we need a better model which can represent the near wall heat transfer more accurate. CFD modeling was used to develop pseudo-continuum model for T(r) using V[subscript r] (r, z) and V[subscript z] (r). To get better temperature at the wall vicinity close to the physical reality. In this model radial thermal conductivity was obtained from Zehner-Schlünder model. The convection heat transfer was calculated in the 2D flow fluid from the CFD run. Results were obtained for Reynolds numbers in the range 240-?1900. The accuracy of the new model has been validated by analytical solution. The temperature calculated by the new velocity field pseudohomogenous energy equation showed reasonable quantitative agreement with values predicted by the CFD model.
Download or read book Theoretical Chemical Engineering Abstracts written by and published by . This book was released on 1984 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Trickle Bed Reactors written by Vivek V. Ranade and published by Elsevier. This book was released on 2011-03-18 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a hybrid methodology for engineering of trickle bed reactors by integrating conventional reaction engineering models with state-of-the-art computational flow models. The content may be used in several ways and at various stages in the engineering process: it may be used as a basic resource for making appropriate reactor engineering decisions in practice; as study material for a course on reactor design, operation, or optimization of trickle bed reactors; or in solving practical reactor engineering problems. The authors assume some background knowledge of reactor engineering and numerical techniques. - Facilitates development of high fidelity models for industrial applications - Facilitates selection and application of appropriate models - Guides development and application of computational models to trickle beds
Download or read book Automobile Catalytic Converters written by Kathleen C. Taylor and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of catalytic converters for the purification of automotive exhaust gases is a relatively new technology which was brought into existence by social pressures for the preservation of acceptable environmental conditions. The majority of catalytic practitioners have been able to watch the growth of this technology from its inception to its current state of sophistication. Automotive catalytic converter technology is now in a mature state, and this chapter from Vol. 5 Catalysis: Science and Technology by Dr. K. C. Taylor provides a review which covers both the process chemistry and the most important converter design factors. Contents 1. Introduction. . . . . . . . . . . . . . 2. Emission Regulations in the United States. 3. Exhaust Emission Characteristics. . 3 4. 1981 Emission Control Technology. 5 A. Converters. . . 5 B. Control System. 7 8 ~. Catalyst Screening . 6. Laboratory Testing. .10 7. The Chemical Reactions 13 8. Composition of Three-Way Catalysts. 16 A. Rhodium 17 21 B. Platinum. C. Palladium 22 D. Iridium . 22 23 E. Ruthenium and Nickel. F. Cerium Oxide ..... 23 G. Search for Alternatives to Nohle Metals 24 9. Catalyst Supports . 25 A. Pellets .... 26 B. Monoliths . . 26 10. The Transient Behavior of Three-Way Catalysts 27 II. Deterioration of Three-Way Catalysts. 35 A. Thermal Effects. . . . 35 B. Phosphorus Poisoning. . . 37 C. Lead Poisoning. . . . . . · 38 D. Catalyst Poisoning by Sulfur · 40 12. The 0.4 NO,; Research Objective. · 41 13. Control of Diesel Particulate Emissions.
Download or read book Structured Catalysts and Reactors written by Andrzej Cybulski and published by CRC Press. This book was released on 2005-11-02 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in structured catalysts is steadily increasing due to the already proven, as well as potential, advantages of these catalysts. Updating the comprehensive coverage of the first edition published in 1998 with the latest science and applications, Structured Catalysts and Reactors, Second Edition gives detailed information on all aspect
Download or read book The Evaluation of Converters for Exothermic and Endothermic Catalytic Reactions Occurring Within Narrow Temperature Limits written by Gustav Wirth and published by . This book was released on 1950 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scrap Catalytic Converter Guide CODE 3 THOUSAND written by C.A. Green and published by Lulu.com. This book was released on 2016-02-22 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: With over 3,800 codes to every make and model of catalytic converter, including pictures, grades and prices that are extremely close to those of reputable refineries. As well as an additional section that list even more codes in alpha-numerical order, making this latest edition a must have for both serious and novice scrap catalytic converter buyers and sellers. We have compiled the most sought after and hard to acquire codes with their values for the most common and not so common scrap catalytic converters and DPF systems. We have expanded our pricing to include 3 PLATINUM market values ($800, $900 and $1,000), and have also included a chart that will show you how to adjust prices under any Platinum, Palladium and Rhodium market changes. All Buyers of this guide will also receive additional codes via email periodically! GET THE VALUE FOR EACH AND EVERY CATALYTIC CONVERTER! -KNOW WHAT THE REFINERIES KNOW! -STOP OVERPAYING AND UNDERPAYING, AND INCREASE YOUR PROFITS!
Download or read book Fluidized Bed Reactors Processes and Operating Conditions written by John G. Yates and published by Springer. This book was released on 2016-09-27 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fluidized-bed reactor is the centerpiece of industrial fluidization processes. This book focuses on the design and operation of fluidized beds in many different industrial processes, emphasizing the rationale for choosing fluidized beds for each particular process. The book starts with a brief history of fluidization from its inception in the 1940’s. The authors present both the fluid dynamics of gas-solid fluidized beds and the extensive experimental studies of operating systems and they set them in the context of operating processes that use fluid-bed reactors. Chemical engineering students and postdocs as well as practicing engineers will find great interest in this book.
Download or read book Process Intensification written by David Reay and published by Butterworth-Heinemann. This book was released on 2013-06-05 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: Process Intensification: Engineering for Efficiency, Sustainability and Flexibility is the first book to provide a practical working guide to understanding process intensification (PI) and developing successful PI solutions and applications in chemical process, civil, environmental, energy, pharmaceutical, biological, and biochemical systems. Process intensification is a chemical and process design approach that leads to substantially smaller, cleaner, safer, and more energy efficient process technology. It improves process flexibility, product quality, speed to market and inherent safety, with a reduced environmental footprint. This book represents a valuable resource for engineers working with leading-edge process technologies, and those involved research and development of chemical, process, environmental, pharmaceutical, and bioscience systems. - No other reference covers both the technology and application of PI, addressing fundamentals, industry applications, and including a development and implementation guide - Covers hot and high growth topics, including emission prevention, sustainable design, and pinch analysis - World-class authors: Colin Ramshaw pioneered PI at ICI and is widely credited as the father of the technology
Download or read book Transport Phenomena written by Robert Byron Bird and published by . This book was released on 1960 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mathematical Modeling and Numerical Simulations of Automotive Catalytic Converters written by Figen Lacin and published by . This book was released on 2002 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalysis written by James J Spivey and published by Royal Society of Chemistry. This book was released on 2021-06-14 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume looks at modern approaches to catalysis and reviews the extensive literature. Chapters highlight application of 2D materials in biomass conversion catalysis, plasmonic photocatalysis, catalytic demonstration of mesoporosity in the hierarchical zeolite and the effect of surface phase oxides on supported metals and catalysis. Looking to the future a chapter on ab initio machine learning for accelerating catalytic materials discovery is included. Appealing broadly to researchers in academia and industry, these illustrative chapters bridge the gap from academic studies in the laboratory to practical applications in industry not only for catalysis field but also for environmental protection. Other chapters with an industrial perspective include heterogeneous and homogeneous catalytic routes for vinyl acetate synthesis, catalysis for production of jet fuel from renewable sources by HDO/HDC and microwave-assisted catalysis for fuel conversion. Chemical reactions in ball mills is also explored. The book will be of great benefit to any researcher wanting a succinct reference on developments in this area now and looking to the future.
Download or read book Mass Transfer Effects and Variable Productive Area in Fixed Bed Catalytic Converters written by Richard Francis Kayser and published by . This book was released on 1952 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
