Author: Ram B. Gupta Publisher: CRC Press ISBN: 1420005995 Category : Science Languages : en Pages : 960
Book Description
Supercritical fluid extraction is an environmentally safe and cost-effective alternative to traditional organic solvents. Carbon dioxide is widely used as the solvent of choice for applications such as caffeine and nicotine extraction due to its mild critical temperature, nontoxicity, nonflammability, and low cost. Introducing the most complete col
Author: E. Kiran Publisher: Springer Science & Business Media ISBN: 9401139296 Category : Science Languages : en Pages : 602
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: Mamata Mukhopadhyay Publisher: CRC Press ISBN: 142004169X Category : Medical Languages : en Pages : 362
Book Description
Synthesizing research from a wide variety of sources, this work offers a convenient guide to a clean, safe, inexpensive, non-toxic, non-polluting solvent that performs better than most conventional solvents. Natural Extracts Using Supercritical Carbon Dioxide reviews recent developments in the technology and its applications to the food, flavor, fragrance, and pharmaceutical industries. It outlines the many advantages that this method has over traditional methods like steam distillation, solvent extraction, and molecular distillation, and it supports the popular trend toward the use of natural products in these industries.
Author: J.R. Dean Publisher: Springer Science & Business Media ISBN: 940112146X Category : Science Languages : en Pages : 238
Book Description
The continued search for rapid, efficient and cost-effective means of analytical measurement has introduced supercritical fluids into the field of analytical chemistry. Two areas are common: supercritical fluid chroma tography and supercritical fluid extraction. Both seek to exploit the unique properties of a gas at temperatures and pressures above the critical point. The most common supercritical fluid is carbon dioxide, employed because of its low critical temperature (31 °C), inertness, purity, non-toxicity and cheapness. Alternative supercritical fluids are also used and often in conjunction with modifiers. The combined gas-like mass transfer and liquid-like solvating characteristics have been used for improved chroma tographic separation and faster sample preparation. Supercritical fluid chromatography (SFC) is complementary to gas chro matography ( GC) and high performance liquid chromatography (HPLC), providing higher efficiency than HPLC, together with the ability to analyse thermally labile and high molecular weight analytes. Both packed and open tubular columns can be employed, providing the capability to analyse a wide range of sample types. In addition, flame ionization detection can be used, thus providing 'universal' detection.
Author: Maartje F. Kemmere Publisher: John Wiley & Sons ISBN: 3527607056 Category : Technology & Engineering Languages : en Pages : 358
Book Description
Recently, supercritical fluids have emerged as more sustainable alternatives for the organic solvents often used in polymer processes. This is the first book emphasizing the potential of supercritical carbon dioxide for polymer processes from an engineering point of view. It develops a state-of-the-art overview on polymer fundamentals, polymerization reactions and polymer processing in supercritical carbon dioxide. The book covers topics in a multidisciplinary approach starting from polymer chemistry and thermodynamics, going through monitoring, polymerization processes and ending with polymer shaping and post-processing. The authors are internationally recognized experts from different fields in polymer reaction engineering in supercritical fluids. The book was initiated by the Working Party on Polymer Reaction Engineering of the European Federation of Chemical Engineering and further renowned international experts.
Author: Murat O. Balaban Publisher: John Wiley & Sons ISBN: 1118243323 Category : Technology & Engineering Languages : en Pages : 337
Book Description
Dense phase carbon dioxide (DPCD) is a non-thermal method for food and pharmaceutical processing that can ensure safe products with minimal nutrient loss and better preserved quality attributes. Its application is quite different than, for example, supercritical extraction with CO 2 where the typical solubility of materials in CO 2 is in the order of 1% and therefore requires large volumes of CO 2. In contrast, processing with DPCD requires much less CO 2 (between 5 to 8% CO 2 by weight) and the pressures used are at least one order of magnitude less than those typically used in ultra high pressure (UHP) processing. There is no noticeable temperature increase due to pressurization, and typical process temperatures are around 40°C. DPCD temporarily reduces the pH of liquid foods and because oxygen is removed from the environment, and because the temperature is not high during the short process time (typically about five minutes in continuous systems), nutrients, antioxidant activity, and vitamins are much better preserved than with thermal treatments. In pharmaceutical applications, DPCD facilitates the production of micronized powders of controlled particle size and distribution. Although the capital and operating costs are higher than that of thermal treatments, they are much lower than other non-thermal technology operations. This book is the first to bring together the significant amount of research into DPCD and highlight its effectiveness against microorganisms and enzymes as well as its potential in particle engineering. It is directed at food and pharmaceutical industry scientists and technologists working with DPCD and other traditional or non-thermal technologies that can potentially be used in conjunction with DPCD. It will also be of interest to packaging specialists and regulatory agencies.
Author: Joseph M. DeSimone Publisher: Oxford University Press, USA ISBN: 0195154835 Category : Language Arts & Disciplines Languages : en Pages : 276
Book Description
Annotation. Introduction, J. Young, J. DeSimone, and W. TumasPart I: Catalysis and Chemical Synthesis in CO21. Phase behavior and its effects on reactions in liquid and supercritical CO2, L.A. Blanchard et al. 2. Advances in homogeneous, heterogeneous and biphasic metal catalyzed reactions in dense phase carbon dioxide, T. Ikariya et al. 3. CO2 as a reactant and solvent in catalysis, T. Ikariya and R. Noyori4. Free radical chemistry in supercritical CO2, J.M. Tanko5. Fluorous phases and compressed carbon dioxide as alternative solvents for chemical synthesis: a comparison, W. Leitner6. Enzyme chemistry in carbon dioxide, R.L. Rodney and A.J. RussellPart II: Polymers in CO27. Solubility of polymers in CO2, M. McHugh8. Interfacial phenomena with CO2-soluble surfactants, K. Johnston et al. 9. Synthesis and characterization of polymers: From polymeric micelles to step growth polymerizations, J. Young and J. DeSimone10. Preparation and studies of polymer/polymer composites prepared using supercritical carbon dioxide, E. Kung, A.J. Lesser, and T.J. McCarthy11. Rheological properties of polymers modified with CO2, C.W. Manke and E. GulariPart III: Industrial Processes and Applications Utilizing CO212. Coatings from liquid and supercritical CO2, Y. Chernyak et al. 13. Dry cleaning with liquid CO2, G. Stewart14. Selective and complete hydrogenation of vegetable oils and free fatty acids in supercritical fluids, T. Tacke, S. Wieland, and P. Panster15. Supercritical CO2 enhancement of cemented materials, C. Taylor, J. Rubin, and B. Carey.
Author: Jose L. Martinez Publisher: CRC Press ISBN: 1420006517 Category : Science Languages : en Pages : 424
Book Description
Enhanced concern for the quality and safety of food products, increased preference for natural products, and stricter regulations on the residual level of solvents, all contribute to the growing use of supercritical fluid technology as a primary alternative for the extraction, fractionation, and isolation of active ingredients. As a solvent-free p
Author: John M. Prausnitz Publisher: Pearson Education ISBN: 0132440504 Category : Science Languages : en Pages : 1150
Book Description
The classic guide to mixtures, completely updated with new models, theories, examples, and data. Efficient separation operations and many other chemical processes depend upon a thorough understanding of the properties of gaseous and liquid mixtures. Molecular Thermodynamics of Fluid-Phase Equilibria, Third Edition is a systematic, practical guide to interpreting, correlating, and predicting thermodynamic properties used in mixture-related phase-equilibrium calculations. Completely updated, this edition reflects the growing maturity of techniques grounded in applied statistical thermodynamics and molecular simulation, while relying on classical thermodynamics, molecular physics, and physical chemistry wherever these fields offer superior solutions. Detailed new coverage includes: Techniques for improving separation processes and making them more environmentally friendly. Theoretical concepts enabling the description and interpretation of solution properties. New models, notably the lattice-fluid and statistical associated-fluid theories. Polymer solutions, including gas-polymer equilibria, polymer blends, membranes, and gels. Electrolyte solutions, including semi-empirical models for solutions containing salts or volatile electrolytes. Coverage also includes: fundamentals of classical thermodynamics of phase equilibria; thermodynamic properties from volumetric data; intermolecular forces; fugacities in gas and liquid mixtures; solubilities of gases and solids in liquids; high-pressure phase equilibria; virial coefficients for quantum gases; and much more. Throughout, Molecular Thermodynamics of Fluid-Phase Equilibria strikes a perfect balance between empirical techniques and theory, and is replete with useful examples and experimental data. More than ever, it is the essential resource for engineers, chemists, and other professionals working with mixtures and related processes.
Author: Ram B. Gupta
Author: E. Kiran
Author: Mamata Mukhopadhyay
Author: J.R. Dean
Author: Maartje F. Kemmere
Author: Murat O. Balaban
Author: J. M. Prausnitz
Author: Joseph M. DeSimone
Author: Jose L. Martinez
Author: John M. Prausnitz