EBookClubs

Read Books & Download eBooks Full Online

EBookClubs

Read Books & Download eBooks Full Online

Book On the Prediction of Gas Hold up in Ebullated Bed Reactors

Download or read book On the Prediction of Gas Hold up in Ebullated Bed Reactors written by Amir Mowla and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Commercial ebullated bed reactors (EBRs) are three-phase fluidized bed systems used for hydroprocessing (upgrading) of bitumen, a major Canadian resource. The objective of this thesis is to improve the understanding of the hydrodynamics of the EBRs through a combination of experimental investigation and CFD modeling. The experiments were conducted in a transparent cold-flow pilot scale reactor (inner diameter of 15.2 cm and total height of 2.2 m and were focused on the most important parameter in the design and operation of fluidized bed systems, i.e., the overall (average) gas hold-up. The pilot scale setup was operated in both two-phase (gas-liquid) and three-phase (gas-liquid-solid) modes in order to investigate the fluid dynamics in the bed and the freeboard regions present in EBRs. In two-phase flow mode, experiments were performed with and without internal gas/liquid separators (recycle cups connected to a recycle line). The recycle cups were fabricated on the basis of designs proposed in the patent literature using a desktop 3-D printer. Different concentrations of ethanol were added to distilled water in order to reproduce the conditions of high gas hold-up and foaming frequently observed in commercial EBRs. The two-phase systems were also simulated with the Euler-Euler model using a finite volume method in the OpenFOAM toolbox. The average bubble size is a key input to this model and must be representative of the physical system. Provided this condition is met, the Euler-Euler model can predict the average gas hold-up under conditions of homogeneous (dispersed) two-phase flow to within 10% of the experimental values, regardless of the mode of operation (co-current vs. bubble column). Predictions of the gas hold-up under conditions of co-current heterogeneous two-phase flow are, however, less accurate (22% average error) - a result likely linked to limitations of the available empirical swarm correction models. Experiments in the systems with recycle cups showed that the performance of the cups in gas/liquid separation deteriorated in foaming systems. Also increasing the inlet liquid flow rate and/or recycle liquid flow increased the amount of entrained gas in the recycle stream. Simulation of these experiments highlighted the strengths and limitations of the Euler-Euler model. As far as three-phase systems are concerned, a meta-analysis of a large body of published data produced a set of empirical correlations for predicting the overall gas hold-up data for systems operating with water and spherical particles. Experiments conducted to investigate the effect of particle wettability on the gas hold-up in a three-phase fluidized bed demonstrated the limitations of such an empirical approach. For the system operating with hydrophilic particles, gas hold-up values of up to 15% were predicted with less than 25% error by the most accurate correlations. For the system of hydrophobic particles, however, the correlations failed in prediction of gas hold-up and the average error was more than 56%. Experiments demonstrated that rendering the particles hydrophobic decreased the gas hold-up by more than 20%. This was found to be the result of larger bubble size distribution in the bed of hydrophobic particles. In these systems, adhesion of bubbles to particles formed bubble-particle agglomerates with less apparent density than bare particles. Such gas-padded particles have less ability to penetrate and break-up the bubbles. Consequently, the average bubble size was larger in the bed of hydrophobic particles and also in the freeboard region above the bed. According to the semi-empirical models on foam height dynamics, steady state foam thickness is inversely proportional to the bubble diameter. Therefore, foam thickness is expected to be smaller for the system of hydrophobic particles. The foam thickness measurements in this study were consistent with the findings of the semi-empirical models.

Book American Doctoral Dissertations

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1998 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Hydrodynamic Aspects of a Three phase Fluidized Bed Reactor

Download or read book Hydrodynamic Aspects of a Three phase Fluidized Bed Reactor written by Michael John Bly and published by . This book was released on 1992 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Hydrodynamics and Mass Transfer in Downflow Slurry Bubble Columns

Download or read book Hydrodynamics and Mass Transfer in Downflow Slurry Bubble Columns written by Subrata Kumar Majumder and published by Apple Academic Press. This book was released on 2021-03-31 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Slurry bubble column reactors are intensively used as a multiphase reactor in the chemical, biochemical, and petrochemical industries for carrying out reactions and mass transfer operations in which a gas, made up of one or several reactive components, comes into contact or reacts with a liquid. This volume describes the hydrodynamics of three-phase gas-liquid-solid flow in a downflow slurry bubble column. The efficiency of the downflow gas interacting system is characterized by the self-entrainment of secondary gas. The book covers the gas entrainment phenomena, gas holdup characteristics, pressure drop, gasliquid mixing characteristics, bubble size distribution, interfacial phenomena, and the mass transfer phenomena in the downflow slurry system. This volume will be useful in chemical and biochemical industries and in industrial research and development sectors, as well as in advanced education courses in this area. The book will be helpful for further understanding the multiphase behavior in gas interacting multiphase systems for research and development. The hydrodynamic and mass transfer characteristics discussed will be useful in the design and installation of the modified slurry bubble column in industry for specific applications.

Book Gas Liquid Solid Foam Reactors

Download or read book Gas Liquid Solid Foam Reactors written by Stemmet and published by . This book was released on 2008 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Hydrodynamic Behaviour of a Three phase Gas liquid solid Airlift Reactor

Download or read book Hydrodynamic Behaviour of a Three phase Gas liquid solid Airlift Reactor written by Ron Solomon Douek and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Dispersed Bubble Reactor for Enhanced Gas liquid solids Contact and Mass Transfer

Download or read book Dispersed Bubble Reactor for Enhanced Gas liquid solids Contact and Mass Transfer written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An apparatus to promote gas-liquid contact and facilitate enhanced mass transfer. The dispersed bubble reactor (DBR) operates in the dispersed bubble flow regime to selectively absorb gas phase constituents into the liquid phase. The dispersion is achieved by shearing the large inlet gas bubbles into fine bubbles with circulating liquid and additional pumped liquid solvent when necessary. The DBR is capable of handling precipitates that may form during absorption or fine catalysts that may be necessary to promote liquid phase reactions. The DBR can be configured with multistage counter current flow sections by inserting concentric cylindrical sections into the riser to facilitate annular flow. While the DBR can absorb CO.sub. 2 in liquid solvents that may lead to precipitates at high loadings, it is equally capable of handling many different types of chemical processes involving solids (precipitates/catalysts) along with gas and liquid phases.

Book Oil and Gas Production Handbook  An Introduction to Oil and Gas Production

Download or read book Oil and Gas Production Handbook An Introduction to Oil and Gas Production written by Havard Devold and published by Lulu.com. This book was released on 2013 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Measurement Techniques for Local and Global Fluid Dynamic Quantities in Two and Three Phase Systems

Download or read book Measurement Techniques for Local and Global Fluid Dynamic Quantities in Two and Three Phase Systems written by and published by . This book was released on 1996 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents a critical review of the methods available for assessing the fluid dynamic parameters in large industrial two and three phase bubble column and slurry bubble column reactors operated at high pressure and temperature. The physical principles behind various methods are explained, and the basic design of the instrumentation needed to implement each measurement principle is discussed. Fluid dynamic properties of interest are: gas, liquid and solids holdup and their axial and radial distribution as well as the velocity distribution of the two (bubble column) or three phases (slurry bubble column). This information on operating pilot plant and plant reactors is essential to verify the computational fluid dynamic codes as well as scale-up rules used in reactor design. Without such information extensive and costly scale-up to large reactors that exploit syngas chemistries, and other reactors in production of fuels and chemicals, cannot be avoided. In this report, available measurement techniques for evaluation of global and local phase holdups, instantaneous and average phase velocities and for the determination of bubble sizes in gas-liquid and gas-liquid-solid systems are reviewed. Advantages and disadvantages of various techniques are discussed. Particular emphasis is placed on identifying methods that can be employed on large scale, thick wall, high pressure and high temperature reactors used in the manufacture of fuels and chemicals from synthesis gas and its derivatives.

Book Processing of Heavy Crude Oils

Download or read book Processing of Heavy Crude Oils written by Ramasamy Marappa Gounder and published by . This book was released on 2019-12-18 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Emulsions  Foams  and Suspensions

Download or read book Emulsions Foams and Suspensions written by Laurier L. Schramm and published by John Wiley & Sons. This book was released on 2006-05-12 with total page 463 pages. Available in PDF, EPUB and Kindle. Book excerpt: Until now colloid science books have either been theoretical, or focused on specific types of dispersion, or on specific applications. This then is the first book to provide an integrated introduction to the nature, formation and occurrence, stability, propagation, and uses of the most common types of colloidal dispersion in the process-related industries. The primary focus is on the applications of the principles, paying attention to practical processes and problems. This is done both as part of the treatment of the fundamentals, where appropriate, and also in the separate sections devoted to specific kinds of industries. Throughout, the treatment is integrated, with the principles of colloid and interface science common to each dispersion type presented for each major physical property class, followed by separate treatments of features unique to emulsions, foams, or suspensions. The first half of the book introduces the fundamental principles, introducing readers to suspension formation and stability, characterization, and flow properties, emphasizing practical aspects throughout. The following chapters discuss a wide range of industrial applications and examples, serving to emphasize the different methodologies that have been successfully applied. Overall, the book shows how to approach making emulsions, foams, and suspensions with different useful properties, how to propagate them, and how to prevent their formation or destabilize them if necessary. The author assumes no prior knowledge of colloid chemistry and, with its glossary of key terms, complete cross-referencing and indexing, this is a must-have for graduate and professional scientists and engineers who may encounter or use emulsions, foams, or suspensions, or combinations thereof, whether in process design, industrial production, or in related R&D fields.

Book Flotation Technology

Download or read book Flotation Technology written by Lawrence K. Wang and published by Springer Science & Business Media. This book was released on 2010-06-09 with total page 694 pages. Available in PDF, EPUB and Kindle. Book excerpt: The past 30 years have seen the emergence of a growing desire worldwide that positive actions be taken to restore and protect the environment from the degrading effects of all forms of pollution – air, water, soil, and noise. Since pollution is a direct or indirect consequence of waste, the seemingly idealistic demand for “zero discharge” can be construed as an unreal- tic demand for zero waste. However, as long as waste continues to exist, we can only attempt to abate the subsequent pollution by converting it to a less noxious form. Three major questions usually arise when a particular type of pollution has been identi?ed: (1) How serious is the pollution? (2) Is the technology to abate it available? and (3) Do the costs of abatement justify the degree of abatement achieved? This book is one of the volumes of the Handbook of Environmental Engineering series. The principal intention of this series is to help readers formulate answers to the last two questions above. The traditional approach of applying tried-and-true solutions to speci?c pollution p- blems has been a major contributing factor to the success of environmental engineering and has accounted in large measure for the establishment of a “methodology of pollution control. ” However, the realization of the ever-increasing complexity and interrelated nature of current environmental problems renders it imperative that intelligent planning of pollution abatement systems be undertaken.

Book Handbook of Biomass Downdraft Gasifier Engine Systems

Download or read book Handbook of Biomass Downdraft Gasifier Engine Systems written by Thomas B. Reed and published by Biomass Energy Foundation. This book was released on 1988 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book CRC Handbook of Metal Etchants

Download or read book CRC Handbook of Metal Etchants written by Perrin Walker and published by CRC Press. This book was released on 1990-12-11 with total page 1434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication presents cleaning and etching solutions, their applications, and results on inorganic materials. It is a comprehensive collection of etching and cleaning solutions in a single source. Chemical formulas are presented in one of three standard formats - general, electrolytic or ionized gas formats - to insure inclusion of all necessary operational data as shown in references that accompany each numbered formula. The book describes other applications of specific solutions, including their use on other metals or metallic compounds. Physical properties, association of natural and man-made minerals, and materials are shown in relationship to crystal structure, special processing techniques and solid state devices and assemblies fabricated. This publication also presents a number of organic materials which are widely used in handling and general processing...waxes, plastics, and lacquers for example. It is useful to individuals involved in study, development, and processing of metals and metallic compounds. It is invaluable for readers from the college level to industrial R & D and full-scale device fabrication, testing and sales. Scientific disciplines, work areas and individuals with great interest include: chemistry, physics, metallurgy, geology, solid state, ceramic and glass, research libraries, individuals dealing with chemical processing of inorganic materials, societies and schools.