Mass Transfer Through Rotating Membranes

Mass Transfer Through Rotating Membranes PDF Author: William George Smith
Publisher:
ISBN:
Category :
Languages : en
Pages : 268

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Book Description

Mass Transfer Through Rotating Membranes

Mass Transfer Through Rotating Membranes PDF Author: William George Smith
Publisher:
ISBN:
Category :
Languages : en
Pages : 268

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Book Description


Fluid Dynamics and Mass Transport in Rotating Channels with Application to Centrifugal Membrane Separation

Fluid Dynamics and Mass Transport in Rotating Channels with Application to Centrifugal Membrane Separation PDF Author: Jon George Pharoah
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Centrifugal membrane and density separation (CMS) is a novel technology proposed for treatment of waste water and industrial process streams. This cross flow filtration process combines the energy recovery inherent to centrifugal reverse osmosis (CRO) with the potential alleviation of membrane fouling and concentration polarization due to the favourable effects of centrifugal and Coriolis accelerations. This dissertation presents a computational study of CMS undertaken to understand the basic hydrodynamics and mass transfer of the processes and to provide insight for the design of CMS devices. Two distinct membrane models were developed, the porous wall model (PWM) and the source term model (STM), and incorporated into Computational Fluid Dynamics (CFD) codes which solve the full Navier-Stokes equations coupled to a scalar transport equation which accounts for dissolved species. These models are used to simulate two and three dimensional laminar flows in both non-rotating and rotating reverse osmosis membrane cartridges and to predict permeate fluxes. Plate and frame geometries are first examined and it is determined that CMS benefits most from channels with streamwise directions directed radially. It is also shown that the benefits of CMS can be attributed largely to the secondary flows and mixing associated with Coriolis acceleration, and the PWM and the STM are found to perform similarly in the case of reverse osmosis. Next, the STM is used to perform a parametric study of the flow and mass transfer in rectangular and square rotating channels. It is shown that while normal rotation is preferable to spanwise rotation, relatively small deviations from the spanwise orientation are adequate to achieve most of the normal rotation performance, and that differences between the two orientations are minimal in the case of square channels. Also, the flow characteristics are again shown to correlate well with the magnitude of the Coriolis acceleration. Flows in triangular and circular channels are also considered, and are shown to perform similarly to rectangular channels. These channel orientations have application in hollow fiber membrane modules and potentially in spiral wound membrane modules. Finally, the flow and mass transfer in channels with periodic streamwise obstacles are considered. Such obstacles are related to feed spacers used in spiral wound membrane elements and impact considerably on the flow characteristics and mass transfer performance. Flow obstacles are shown to increase mass transfer performance in all cases, with alternating surface mounted performing best. A preliminary investigation is undertaken into rotating flows with periodic obstacles, and the flow fields are shown to depend strongly on the blockage ratio and on the Rossby number. In most cases, it is found that mass transfer performance does not necessarily correlate with either wall shear stress or the local flow field. Several general conclusions regarding CMS can be drawn from this work. It is preferable to operate a CMS devices at low flow rates, which is contrary to conventional wisdom in membrane separation. Secondly, the mixing induced by channel rotation is both more effective and more efficient than the mixing induced by the feed spacers considered here. Finally, the magnitude of the Coriolis acceleration is the dominant parameter in determining CMS performance. This means that a CMS device can either operate at relatively low rotational speeds with flow in the radial direction, or at higher speeds but lower angles of inclination with respect to the rotational axis.

Basic Equations of Mass Transport Through a Membrane Layer

Basic Equations of Mass Transport Through a Membrane Layer PDF Author: Endre Nagy
Publisher: Elsevier
ISBN: 0128137231
Category : Technology & Engineering
Languages : en
Pages : 594

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Book Description
Basic Equations of Mass Transport Through a Membrane Layer, Second Edition, has been fully updated to deliver the latest research in the field. This volume covers the essentials of compound separation, product removal, concentration, and production in the chemical, biochemical, pharmaceutical, and food industries. It outlines the various membrane processes and their applications, offering a detailed mathematical description of mass transport and defining basic mass transport and concentration distribution expressions. Additionally, this book discusses the process parameters and application of the expressions developed for a variety of industrial applications. Comprehensive explanations of convective/diffusive mass transport are provided, both with and without polarization layers, that help predict and process performance and facilitate improvements to operation conditions and efficiency. Basic Equations of Mass Transport Through a Membrane Layer is an ideal resource for engineers and technologists in the chemical, biochemical, and pharmaceutical industries, as well as researchers, professors, and students in these areas at both an undergraduate and graduate level. Cites and analyzes mass transport equations developed for different membrane processes. Examines the effect of biochemical/chemical reactions in the presence of convective and diffusive flows in plane and cylindrical spaces. Defines the mass transfer rate for first- and zero-order reactions and analytical approaches are given for other-order reactions in closed mathematical forms. Analyzes the simultaneous convective and diffusive transports with same or different directions.

Handbook of Membrane Separations

Handbook of Membrane Separations PDF Author: Anil K. Pabby
Publisher: CRC Press
ISBN: 1003811604
Category : Science
Languages : en
Pages : 1334

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Book Description
The third edition of the Handbook of Membrane Separations: Chemical, Pharmaceutical, Food, and Biotechnological Applications provides a comprehensive discussion of membrane applications. Fully updated to include the latest advancements in membrane science and technology, it is a one-of-its-kind overview of the existing literature. This fully illustrated handbook is written by experts and professionals in membrane applications from around the world. Key Features: • Includes entirely new chapters on organic solvent-resistant nanofiltration, membrane condensers, membrane-reactors in hydrogen production, membrane materials for haemodialysis, and integrated membrane distillation • Covers the full spectrum of membrane technology and its advancements • Explores membrane applications in a range of fields, from biotechnological and food processing to industrial waste management and environmental engineering This book will appeal to both newcomers to membrane science as well as engineers and scientists looking to expand their knowledge on upcoming advancements in the field.

Mass Transfer in Corrugated Membranes

Mass Transfer in Corrugated Membranes PDF Author: Ann McLaughry Gronda
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages : 366

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Enhancing an Air to Liquid Mass Transfer Unit

Enhancing an Air to Liquid Mass Transfer Unit PDF Author: Ahmad Abu Hajer
Publisher:
ISBN:
Category : Carbon
Languages : en
Pages :

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Book Description
The aim of this study was to enhance a vertical rotating membrane system that induced gas to liquid mass transfer, and to evaluate its performance by quantifying its inorganic carbon formation rate under different parameters such as carbon dioxide concentration in air, membrane's rotational speed and the composition of the liquid medium. In addition to that, the ability of the zinc plated and nickel wire meshes to catalyze the hydration reaction of carbon dioxide was tested in this study using a bench scale rotating membrane system. The system was enhanced by replacing the mechanism that rotated the mass transfer membrane mesh by a simpler mechanism which depended on rollers to rotate the membrane mesh.

Handbook of Membrane Separations

Handbook of Membrane Separations PDF Author: Anil K. Pabby
Publisher: CRC Press
ISBN: 0849395496
Category : Science
Languages : en
Pages : 1210

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Book Description
The Handbook of Membrane Separations: Chemical, Pharmaceutical, and Biotechnological Applications provides detailed information on membrane separation technologies as they have evolved over the past decades. To provide a basic understanding of membrane technology, this book documents the developments dealing with these technologies. It explores chemical, pharmaceutical, food processing and biotechnological applications of membrane processes ranging from selective separation to solvent and material recovery. This text also presents in-depth knowledge of membrane separation mechanisms, transport models, membrane permeability computations, membrane types and modules, as well as membrane reactors.

Membranes in Bioprocessing: Theory and Applications

Membranes in Bioprocessing: Theory and Applications PDF Author: J.A. Howell
Publisher: Springer Science & Business Media
ISBN: 9401121567
Category : Science
Languages : en
Pages : 341

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Book Description
1. A. HOWELL School ofChemical Engineering, University ofBath, Claverton Down, Bath, UK, BA2 7AY 1.1 WHAT IS A MEMBRANE PROCESS? Every day over 20 million litres of brackish water are pumped out of the ground near Jeddah in Saudi Arabia and passed through thin sheets of cellulose acetate known as reverse osmosis membranes before being used as part of the city's water supply. In St Maurice les Chateauneuf, France three million litres a day of ground water are ultrafiltered to supply the city and on test sites in Australia settled sewage is being disinfected by being passed through microfiltration membranes. Many of the foods we eat and beverages we drink have used membranes during their processing. Orange juice can be concentrated by membranes to make a concentrate which retains more of the flavour than does evaporation. Milk can be concentrated slightly by means of a membrane before making a cheese in a process which produces no whey. Gases rising from the ground in a waste tip can be piped away and the carbon dioxide separated from the methane by a membrane process allowing the methane then to be used as a fuel, simultaneously saving energy and reducing the greenhouse effect since methane is more effective as a greenhouse gas than carbon dioxide.

Handbook of Membrane Separations

Handbook of Membrane Separations PDF Author: Anil Kumar Pabby
Publisher: CRC Press
ISBN: 1466555580
Category : Science
Languages : en
Pages : 868

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Book Description
The Handbook of Membrane Separations: Chemical, Pharmaceutical, Food, and Biotechnological Applications, Second Edition provides detailed information on membrane separation technologies from an international team of experts. The handbook fills an important gap in the current literature by providing a comprehensive discussion of membrane application

Reactive and Membrane-Assisted Separations

Reactive and Membrane-Assisted Separations PDF Author: Philip Lutze
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110388200
Category : Technology & Engineering
Languages : en
Pages : 523

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Book Description
Process intensification aims for increasing efficiency and sustainability of (bio-)chemical production processes. This book presents strategies for improving fluid separation such as reactive distillation, reactive absorption and membrane assisted separations. The authors discuss computer simulation, model development, methodological approaches for synthesis and the design and scale-up of final industrial processes.