Visualization of Particle Formation Processes in Supercritical Fluids PDF Download

Author: Amendi Pennington Stephens
Publisher:
ISBN:
Category : Crystallization
Languages : en
Pages : 296

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Book Description

Author: Michael Turk
Publisher: Elsevier
ISBN: 0444594434
Category : Technology & Engineering
Languages : en
Pages : 153

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Book Description
Particle formation with supercritical fluids is a promising alternative to conventional precipitation processes as it allows the reduction of particle size and control of morphology and particle size distribution without degradation or contamination of the product. The book comprehensively examines the current status of research and development and provides perspectives and insights on promising future directions.The introduction to high pressure and high temperature phase equilibria and nucleation phenomena provides the basic principles of the underlying physical and chemical phenomena, allowing the reader an understanding of the relationship between process conditions and particle characteristics.Bridging the gap between theory and application, the book imparts the scientific and engineering fundamentals for innovative particle formation processes. The interdisciplinary "modus operandi" will encourage cooperation between scientists and researchers from different but complementary disciplines. - Focuses on the general principles of particle formation in supercritical fluids - Considers high pressure and high temperature phase equilibria, fluid dynamics and nucleation theory - Discusses the underlying physical and chemical phenomena needed to understand the different applications, pointing out the relationship between process conditions and product properties

Author: Richard Smith
Publisher: Elsevier Inc. Chapters
ISBN: 0128076879
Category : Technology & Engineering
Languages : en
Pages : 60

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Book Description

Author: E. Kiran
Publisher: Springer Science & Business Media
ISBN: 9401139296
Category : Science
Languages : en
Pages : 602

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Book Description
Supercritical fluids are neither gas nor liquid, but can be compressed gradually from low to high density and they are therefore interesting and important as tunable solvents and reaction media in the chemical process industry. By adjusting the density the properties of these fluids can be customised and manipulated for a given process - physical or chemical transformation. Separation and processing using supercritical solvents such as CO2 are currently on-line commercially in the food, essential oils and polymer industries. Many agencies and industries are considering the use of supercritical water for waste remediation. Supercritical fluid chromatography represents another, major analytical application. Significant advances have recently been made in materials processing, ranging from particle formation to the creation of porous materials. The chapters in this book provide tutorial accounts of topical areas centred around: (1) phase equilibria, thermodynamics and equations of state; (2) critical behaviour, crossover effects; (3) transport and interfacial properties; (4) molecular modelling, computer simulation; (5) reactions, spectroscopy; (6) phase separation kinetics; (7) extractions; (8) applications to polymers, pharmaceuticals, natural materials and chromatography; (9) process scale-up.

Author: Mazen H. Hanna
Publisher:
ISBN:
Category :
Languages : en
Pages : 238

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Book Description
A novel apparatus and methods of controlled particle formation from supercritical fluids are proposed. A solution of the material of interest is fed together with a fluid (e.g. CO2) above its critical point through a concentric nozzle into a high pressure vessel. The temperature and pressure of the vessel are controlled by a thermocouple and an automated back pressure regulator respectively. The supercritical fluid disperses, mixes and rapidly extracts the solvent leading to formation of particulate products. The products are retained in the high pressure vessel by a particle retention device. The supercritical solution (i.e. the supercritical fluid and the solvent) emerging from the back pressure regulator is allowed to expand so that the solvent may separate from the gas, and both are recycled. By changing the working conditions of pressure, temperature and flow rate of the solution to the supercritical fluid, it is possible to control the size, shape and morphology of the products - increase of the pressure and/or flow rate of the supercritical fluid led to a decrease in particle size. Products prepared by this new technique include, drug materials, inorganics, polymers, carbohydrates and proteins. Microparticulate products of the drug salmeterol xinafoate exhibit narrow size distribution, batch-to-batch consistency, high degree of crystallinity, enhanced chemical and polymorphic purity, low dynamic bulk density, undetectable amounts of residual solvent content and are free flowing with low dispersion energy due to lack of static charge. This new method of preparation of particles from supercritical fluids has potential applicatlon to industrial particle formation processing avoiding problems of conventional crystallisation procedures.

Author: Richard Smith
Publisher: Newnes
ISBN: 0080931308
Category : Science
Languages : en
Pages : 764

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Book Description
This text provides an introduction to supercritical fluids with easy-to-use Excel spreadsheets suitable for both specialized-discipline (chemistry or chemical engineering student) and mixed-discipline (engineering/economic student) classes. Each chapter contains worked examples, tip boxes and end-of-the-chapter problems and projects. Part I covers web-based chemical information resources, applications and simplified theory presented in a way that allows students of all disciplines to delve into the properties of supercritical fluids and to design energy, extraction and materials formation systems for real-world processes that use supercritical water or supercritical carbon dioxide. Part II takes a practical approach and addresses the thermodynamic framework, equations of state, fluid phase equilibria, heat and mass transfer, chemical equilibria and reaction kinetics of supercritical fluids. Spreadsheets are arranged as Visual Basic for Applications (VBA) functions and macros that are completely (source code) accessible for students who have interest in developing their own programs. Programming is not required to solve problems or to complete projects in the text. - Property worksheets/spreadsheets that are easy to use in learning environments - Worked examples with Excel VBA Worksheet functions allow users to design their own processes - Fluid phase equilibria and chemical equilibria worksheets allow users to change conditions, study new solutes, co-solvents, chemical systems or reactions

Author: A. Montes
Publisher:
ISBN: 9789533076362
Category :
Languages : en
Pages :

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Author: Harry Schulz
Publisher: BoD – Books on Demand
ISBN: 9533075961
Category : Science
Languages : en
Pages : 462

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Book Description
The phenomena related to the flow of fluids are generally complex, and difficult to quantify. New approaches - considering points of view still not explored - may introduce useful tools in the study of Hydrodynamics and the related transport phenomena. The details of the flows and the properties of the fluids must be considered on a very small scale perspective. Consequently, new concepts and tools are generated to better describe the fluids and their properties. This volume presents conclusions about advanced topics of calculated and observed flows. It contains eighteen chapters, organized in five sections: 1) Mathematical Models in Fluid Mechanics, 2) Biological Applications and Biohydrodynamics, 3) Detailed Experimental Analyses of Fluids and Flows, 4) Radiation-, Electro-, Magnetohydrodynamics, and Magnetorheology, 5) Special Topics on Simulations and Experimental Data. These chapters present new points of view about methods and tools used in Hydrodynamics.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 494

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Book Description

Author: John R. Williams
Publisher: Humana Press
ISBN: 9780896035713
Category : Science
Languages : en
Pages : 256

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Book Description
Over the last 15 years, there has been renewed interest in supercritical fluids owing to their unique properties and relatively low environmental impact. Greatest attention has been given to the extraction and separation of organic compounds. Supercritical fluids have also been successfully used for particle production, as reaction media, and for the destruction of toxic waste. Supercritical carbon dioxide has been the most widely used supercritical fluid, mainly because it is cheap, relatively nontoxic, and has convenient critical values. Supercritical fluids have also been used on analytical and preparative scales for many biological and other applications. Many papers have been published on the use of supercritical fluids. However, few have acted as a detailed instruction manual for those wanting to use the techniques for the first time. We anticipate that this Methods in Biotechnology volume, Supercritical Fluid Methods and Protocols will s- isfy the need for such a book. Every chapter has been written by experienced workers and should, if closely followed, enable workers with some or no previous experience of supercritical fluids to conduct experiments successfully at the first attempt.