Download or read book Supercritical Fluid Cleaning written by Samuel P. Sawan and published by Elsevier. This book was released on 1998-12-31 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although supercritial fluid (SCF) technology is now widely used in extraction and purification processes (in the petrochemical, food and pharmaceuticals industries), this book is the first to address the new application of cleaning. The objective is to provide a roadmap for readers who want to know whether SCF technology can meet their own processing and cleaning needs. It is particularly helpful to those striving to balance the requirements for a clean product and a clean environment. The interdisciplinary subject matter will appeal to scientists and engineers in all specialties ranging from materials and polymer sciences to chemistry and physics. It is also useful to those developing new processes for other applications, and references given at the end of each chapter provide links to the wider body of SCF literature. The book is organized with topics progressing from the fundamental nature of the supercritical state, through process conditions and materials interactions, to economic considerations. Practical examples are included to show how the technology has been successfully applied. The first four chapters consider principles governing SCF processing, detailing issues such as solubility, design for cleanability, and the dynamics of particle removal. The next three chapters discuss surfactants and microemulsions, SCF interaction with polymers, and the use of supercritical carbon dioxide (CO2) as a cleaning solvent. The closing chapters focus on more practical considerations such as scaleup, equipment costs, and financial analysis.
Download or read book Supercritical Fluids Cleaning written by and published by . This book was released on 1991 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper discusses a proposed multi-party research and development program which seeks to develop supercritical fluid cleaning technology as an alternative to existing solvent cleaning applications. While SCF extraction technology has been in commercial use for several years, the use of these fluids as cleaning agents poses several new technical challenges. Problems inherent in the commercialization of SCF technology include: the cleaning efficacy and compatibility of supercritical working fluids with the parts to be cleaned must be assessed for a variety of materials and components; process parameters and equipment design Have been optimized for extractive applications and must be reconsidered for application to cleaning; and co-solvents and entrainers must be identified to facilitate the removal of polar inorganic and organic contaminants, which are often not well solvated in supercritical systems. The proposed research and development program would address these issues and lead to the development and commercialization of viable SCF-based technology for precision cleaning applications. This paper provides the technical background, program scope, and delineates the responsibilities of each principal participant in the program.
Download or read book Effects of Fluid Dynamics on Cleaning Efficacy of Supercritical Fluids written by and published by . This book was released on 1993 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pacific Northwest Laboratory (PNL) and Boeing Aerospace Company are developing a process to clean metal parts using a supercritical solvent. This work is part of an effort to address issues inhibiting the rapid commercialization of Supercritical Fluid Parts Cleaning (SFPC). PNL assembled a SFPC test stand to observe the relationship between the fluid dynamics of the system and the mass transfer of a contaminant from the surface of a contaminated metal coupon into the bulk fluid. The bench-scale test stand consists of a Berty'' autoclave modified for these tests and supporting hardware to achieve supercritical fluids parts cleaning. Three separate sets of tests were conducted using supercritical carbon dioxide. For the first two tests, a single stainless steel coupon was cleaned with organic solvents to remove surface residue, doped with a single contaminant, and then cleaned in the SFPC test stand. Contaminants studied were Dow Corning 200 fluid (dimethylpolysiloxane) and Castle/Sybron X-448 High-temperature Oil (a polybutane/mineral oil mixture). A set of 5-minute cleaning runs was conducted for each dopant at various autoclave impeller speeds. Test results from the first two sets of experiments indicate that precision cleaning for difficult-to-remove contaminants can be dramatically improved by introducing and increasing turbulence within the system. Metal coupons that had been previously doped with aircraft oil were used in a third set of tests. The coupons were placed in the SFPC test stand and subjected to different temperatures, pressures, and run times at a constant impeller speed. The cleanliness of each part was measured by Optically Stimulated Electron Emission. The third set of tests show that levels of cleanliness attained with supercritical carbon dioxide compare favorably with solvent and aqueous cleaning levels.
Download or read book Liquid supercritical Fluid Carbon Dioxide Cleaning of Stainless Steel Components written by L. M. Bagaasen and published by . This book was released on 1991 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluid Dynamic Effects on Precision Cleaning with Supercritical Fluids written by and published by . This book was released on 1994 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pacific Northwest Laboratory staff have assembled a small supercritical fluids parts cleaning test stand to characterize how system dynamics affect the efficacy of precision cleaning with supercritical carbon dioxide. A soiled stainless steel coupon, loaded into a ''Berty'' autoclave, was used to investigate how changes in system turbulence and solvent temperature influenced the removal of test dopants. A pulsed laser beam through a fiber optic was used to investigate real-time contaminant removal. Test data show that cleaning efficiency is a function of system agitation, solvent density, and temperature. These data also show that high levels of cleaning efficiency can generally be achieved with high levels of system agitation at relatively low solvent densities and temperatures. Agitation levels, temperatures, and densities needed for optimal cleaning are largely contaminant dependent. Using proper system conditions, the levels of cleanliness achieved with supercritical carbon dioxide compare favorably with conventional precision cleaning methods. Additional research is currently being conducted to generalize the relationship between cleaning performance and parameters such as contaminant solubilities, mass transfer rates, and solvent agitation. These correlations can be used to optimize cleaning performance, system design, and time and energy consumption for particular parts cleaning applications.
Download or read book Supercritical Carbon Dioxide Cleaning Market Assessment and Commercialization written by and published by . This book was released on 1994 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Through the US Department of Energy's Industrial Waste Program (IWP), work is being conducted to research, develop, and commercialize supercritical fluid cleaning for its potential as a safer technology in a wide range of industrial cleaning operations. Commercialization, which has not proceeded as quickly as expected, is being aided by the Joint Association for the Advancement of Supercritical Technology (JAAST), a research consortium made up of industry, university, and National Laboratory partners. Under the IWP, JAAST is facilitating interaction and communication among those involved in the technology and addressing specific issues slowing its growth and acceptance. As part of the IWP/JAAST effort, Pacific Northwest Laboratory conducted a study to (1) identify and evaluate potential markets for supercritical fluids cleaning, (2) identify and address current perceptions that inhibit the acceptance of the technology into industrial cleaning operations, and (3) develop a plan that will lead to successful deployment and implementation in potential market areas. The approach to gathering the information needed for formulating the plan was to interview several individuals involved in developing, using, or commercializing the technology, specifically, supercritical carbon dioxide (SCCO2), the most commonly used fluid. Several potential markets were identified, including cleaning gyroscope and filling hardware; optical components; instrument bearings; computer disk drive components; medical devices; and fabrics, cloths, and rags. In cases where there are parts with intricate geometries, where water-based cleaning may corrode parts and materials, or where significant time and energy for drying is required, SCCO2 may be an especially attractive alternative. While pursuing these applications, certain barriers still need to be overcome.
Download or read book Elimination of Solvents and Waste by Supercritical Carbon Dioxide in Precision Cleaning written by and published by . This book was released on 1994 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physiochemical properties of supercritical carbon dioxide make it ideally suited for removing commonly encountered contaminants found in the precision cleaning of optical components, computer parts, and electronic assemblies. Data will be presented on a survey demonstrating the successful removal of cutting and machine oils, silicon oils, body oils and hydraulic fluids from a variety of surfaces with supercritical carbon dioxide to, at, or below precision cleaning standards (less than 10 micrograms of contaminant per square centimeter of surface). Replicate studies were performed in both a small bench-scale unit (10 milliliter cleaning vessel) and in a large-scale unit (60 liter, 14 inch diameter cleaning vessel) showing the ability to scale small experiments to commercial sizes. Applicability of this supercritical fluid cleaning technique to commercial operations was evaluated in the areas of contaminant removal efficiencies, surface interactions, operational costs, and environmental waste reduction/elimination.
Download or read book Precision Cleaning with Supercritical Carbon Dioxide for the Elimination of Organic Solvents and the Reduction of Hazardous Wastes written by and published by . This book was released on 1994 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Private and governmental industrial facilities use chlorofluorocarbons and chlorocarbons for the cleaning of a variety of items. The Montreal Protocol (1987) and amendments to this act will phase out the use of chlorofluorocarbons, or CFCs, by the year 2000 because they are toxic, carcinogenic, and implicated in the depletion of the Earth's ozone layer. The United States has pledged to eliminate these substances by 1995. To stay competitive in the global market, US industries require an economical replacement. Supercritical fluids, which have been used in food, fragrance, and petroleum processes for years, are attractive replacement solvents because of their low environmental impact, high diffusivities, low viscosities, and temperature-pressure dependence of solvent strengths. In the case of nontoxic and nonflammable carbon dioxide (CO2), its critical temperature and pressure are readily accessible with well-established process technology and equipment. In addition, applications using a supercritical fluid such as CO2 are generally safer and environmentally benign. Extractions using supercritical CO2 use less energy than distillation and incineration processes and are less expensive than liquid extraction processes using toxic and costly organic solvents. Finally, CO2 has a very high volatility compared to virtually any organic extractant which facilitates its separation from extract solutions for extract recovery and CO2 recycle. Data will be presented on the successful removal of cutting and machine oils, silicone oils, body oils, and hydraulic fluids from a variety of industrial substrates with supercritical CO2 to, at, or below precision cleaning levels (less than 10 micrograms of contaminant per square centimeter of surface). The applicability of this technique to commercial operations was evaluated in this area of contaminant removal, surface interactions, operational costs, and waste reduction and elimination.
Download or read book Supercritical Fluids written by E. Kiran and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Supercritical Fluids as Substitutes for Dry Cleaning Solvents written by Fu-Jung Kao and published by . This book was released on 1995 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Practical Aspects of Chemical Engineering written by Marek Ochowiak and published by Springer. This book was released on 2018-02-07 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on Chemical Engineering and Processing, covering interdisciplinary innovation technologies and sciences closely related to chemical engineering, such as computer image analysis, modelling and IT. The book presents interdisciplinary aspects of chemical and biochemical engineering interconnected with process system engineering, process safety and computer science.
Download or read book Handbook for Critical Cleaning written by Barbara Kanegsberg and published by CRC Press. This book was released on 2000-12-26 with total page 687 pages. Available in PDF, EPUB and Kindle. Book excerpt: With all the cleaning approaches available, how do you choose which one is best for your needs? Components manufacturers wonder which will provide a competitive edge. Chemists and engineers worry about the effect of any process modification on a critical component or on the stability of an irreplaceable antique. There is no silver bullet, n
Download or read book Cleaning with Solvents Science and Technology written by John Durkee and published by William Andrew. This book was released on 2013-11-29 with total page 779 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-precision cleaning is required across a wide range of sectors, including aerospace, defense, medical device manufacturing, pharmaceutical processing, semiconductor/electronics, etc. Cleaning parts and surfaces with solvents is simple, effective and low-cost. Although health and safety and environmental concerns come into play with the use of solvents, this book explores how safe and compliant solvent-based cleaning techniques can be implemented. A key to this is the selection of the right solvent. The author also examines a range of newer "green" solvent cleaning options. This book supplies scientific fundamentals and practical guidance supported by real-world examples. Durkee explains the three principal methods of solvent selection: matching of solubility parameters, reduction of potential for smog formation, and matching of physical properties. He also provides guidance on the safe use of aerosols, wipe-cleaning techniques, solvent stabilization, economics, and many other topics. A compendium of blend rules is included, covering the physical, chemical, and environmental properties of solvents. - Three methods explained in detail for substitution of suitable solvents for those unsuitable for any reason: toxic solvents don't have to be tolerated; this volume explains how to do better - Enables users to make informed judgments about their selection of cleaning solvents for specific applications, including solvent replacement decisions - Explains how to plan and implement solvent cleaning systems that are effective, economical and compliant with regulations
Download or read book Transport Phenomena in the Process of Porous Membrane Cleaning Using Supercritical Fluids written by Jan Krzysztoforski and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Supercritical Fluid Carbon Dioxide Cleaning of Plutonium Parts written by and published by . This book was released on 1991 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical fluid carbon dioxide is under investigation in this work for use as a cleaning solvent for the final cleaning of plutonium parts. These parts must be free of organic residue to avoid corrosion in the stockpile. Initial studies on stainless steel and full-scale mock-up parts indicate that the oils of interest are easily and adequately cleaned from the metal surfaces with supercritical fluid carbon dioxide. Results from compatibility studies show that undesirable oxidation or other surface reactions are not occurring during exposure of plutonium to the supercritical fluid. Cleaning studies indicate that the oils of interest are removed from the plutonium surface under relatively mild conditions. These studies indicate that supercritical fluid carbon dioxide is a very promising cleaning medium for this application.
Download or read book A Feasibility Study of the Use of Supercritical Fluids for the Cleaning of Drill Cuttings written by Jan A. Alfheim and published by . This book was released on 1989 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Novel Metal Electrodeposition and the Recent Application written by Masato Sone and published by BoD – Books on Demand. This book was released on 2019-03-06 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gold and noble metals have been attractive to humans from ancient times because of their beautiful features. In modern society, noble metals, especially gold, play important roles as components in electronic devices because of their high electrical conductivity, chemical stability, and density. In the field of MEMS devices, the demand for continuous miniaturization and sensitivity enhancement is always high. Especially for MEMS accelerometers, sensitivity is affected by Brownian noise, and components with sufficient mass are needed to suppress this noise. Therefore, it is difficult to reduce the dimensions of components to allow further miniaturization of the device. This book presents recent progress in noble metal electrodeposition and applications of gold-based materials in the realization of highly sensitive CMOS-MEMS accelerometers.
