Author: Christopher Russell SydnorPublisher:
ISBN:
Category :
Languages : en
Pages : 176
Book Description
General Reviews of Electrochemical and Corrosion Phenomena Under Conditions Associated with Supercritical Water Oxidation
Author: Christopher Russell SydnorPublisher:
ISBN:
Category :
Languages : en
Pages : 176
Book Description
Corrosion in Supercritical Water Oxidation Systems
Author: R. M. LatanisionPublisher:
ISBN:
Category :
Languages : en
Pages : 28
Book Description
Laboratory and pilot-scale supercritical water oxidation systems are operating today and that field experience indicates that corrosion in the pre-heater, reactor and cool-down sections of SCWO systems does, as expected, occur: accelerated general corrosion, pitting and stress corrosion cracking have been identified. This provides an imperfect and incomplete if, however, important part of the data base that must, ultimately, be considered in producing large scale commercial SCWO systems. Recognizing the gaps which exist in this base of field experience, this workshop created a first cut at a corrosion research agenda that should provide guidance to designers and equipment manufacturers in screening and qualifying materials of construction for SCWO hardware and monitoring devices. The consensus of those present is that wastage (accelerated general corrosion) is less of a concern than stress corrosion cracking which may lead to premature failure of systems components. A test matrix (see Section 4(a)) was established with the view that this matrix should be pursued in a dedicated SCWO system, the goal being to develop the engineering data base necessary to complement field experience which, in turn, would be used in constructing scaled-up systems. The test matrix takes into account the recognition that stress corrosion cracking is intimately a function of the microstructure of candidate materials (which is dependent on the processing history), the chemistry of the service environment, and the state of mechanical stress of the component in question. Stress corrosion cracking will only occur if a susceptible microstructure is exposed to a hostile environment in the presence of tensile stress. If any one of these elements is absent, SCC will not occur. In essence, what is required is an understanding of the range of conditions in SCWO systems where the coincidence of solid state-chemical-mechanical factors converge leading to SCC. The proposed dedicated SCWO test system would be instrumented to monitor pH, Cl-, 02, H2 and electrode potentials as well as crack initiation / propagation rates, the latter likely achieved by the potential drop method. Additionally, given the sometimes very high rate of corrosion (wastage) that has been observed in the field, provision should be made to include test coupons to allow monitoring of both general and localized (pitting) corrosion. As is often true in the development of engineering systems, engineering is likely to outpace fundamental (mechanistic) understanding of failure phenomena. It is likely that as the data base of both field and laboratory experience expands (including required inspection and maintenance tools and approaches) improved systems will be developed. In the interim it is essential to carefully manage the technological, economic and safety-related issues that are attendant with the development of engineering systems of all kinds..
Supercritical Water Oxidation Studies: Understanding the Chemistry and Electrochemistry of SCWO Systems
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
SuperCritical Water Oxidation (SCWO) is being actively developed as a means of destroying highly toxic organic waste and as a way of reducing the volume of low-level nuclear waste. The technology employs water at temperatures above the critical temperature (374.15K) as the reaction medium as well as high partial pressures of oxygen or high concentrations of hydrogen peroxide. These conditions lead to extraordinarily high corrosion rates within + or -50 deg C of Tc, which can be characterized in terms of the pM and redox potential of the medium. In this report, techniques that have been developed under ARO sponsorship for measuring pM, redox potential, O2, H2, and corrosion activity at high subcritical and at supercritical temperatures are described. We show that measurement of many important chemistry and corrosion parameters is technically developed in this study will allow for in close control of the reaction medium.
Hydrothermal and Supercritical Water Processes
Author: Gerd BrunnerPublisher: Elsevier
ISBN: 0444594183
Category : Science
Languages : en
Pages : 683
Book Description
Hydrothermal and Supercritical Water Processes presents an overview on the properties and applications of water at elevated temperatures and pressures. It combines fundamentals with production process aspects. Water is an extraordinary substance. At elevated temperatures (and pressures) its properties change dramatically due to the modifications of the molecular structure of bulk water that varies from a stable three-dimensional network, formed by hydrogen bonds at low and moderate temperatures, to an assembly of separated polar water molecules at high and supercritical temperatures. With varying pressure and temperature, water is turned from a solvent for ionic species to a solvent for polar and non-polar substances. This variability and an enhanced reactivity of water have led to many practical applications and to even more research activities, related to such areas as energy transfer, extraction of functional molecules, unique chemical reactions, biomass conversion and fuel materials processing, destruction of dangerous compounds and recycling of useful ones, growth of monolithic crystals, and preparation of metallic nanoparticles. This book provides an introduction into the wide range of activities that are possible in aqueous mixtures. It is organized to facilitate understanding of the main features, outlines the main applications, and gives access to further information - Summarizes fundamental properties of water for engineering applications - Compares process and reactor designs - Evaluates processes from thermodynamic, economic, and social impact viewpoints
Preliminary Corrosion Studies of Candidate Materials for Supercritical Water Oxidation Reactor Systems
Author: John Clarke OrzalliPublisher:
ISBN:
Category : Corrosive wastes
Languages : en
Pages : 316
Book Description
An experimental test facility has been designed and constructed for investigation of the corrosion behavior of candidate materials in a supercritical water oxidation environment. The high temperatures (500 deg C) and high pressures (300 atm) required in this process, made the experimental apparatus construction and control a complex engineering problem. The facility consists of two systems. The first is an exposure autoclave internal volume 850 ml, with associated monitoring and control systems for conducting long term exposure testing of test coupons and U-bends. The second is an electrochemical cell with a potentiostat and frequency response analyzer for conducting Electronic Impedance Spectroscopy (EIS) in the supercritical water environment. Exposure testing of three candidate materials; Inconel 625, Hastelloy C-276 and 316 stainless steel was conducted at three temperature regimes corresponding to three locations in a SCWO waste treatment system. Preliminary results are presented in an environment of demineralized water as a control. Experimental results indicate evidence of a film on the materials characterized by slight weight gain. Light and confocal laser light microscopic evaluations revealed the presence of localized pitting corrosion on the Inconel 625.
Chemical Degradation Methods for Wastes and Pollutants
Author: Matthew A. TarrPublisher: CRC Press
ISBN: 0824756479
Category : Science
Languages : en
Pages : 452
Book Description
Chemical Degradation Methods for Wastes and Pollutants focuses on established and emerging chemical procedures for the management of pollutants in industrial wastewater and the environment. This reference offers an in-depth explanation of the degradation process, mechanisms, and control factors affecting each method, as well as issues crucial to the application of these approaches in real-world treatment sites. It examines ten of the most common and useful chemical technologies for environmental remediation and sanitation of industrial waste streams and offers implementation guidelines and examples of remediation strategies that are crucial to effective wastewater cleansing.
Innovations in Supercritical Fluids
Author: Keith W. HutchensonPublisher:
ISBN:
Category : Science
Languages : en
Pages : 488
Book Description
Presents an overview of supercritical fluid science and technology with emphasis on developments in solubility and modeling. Provides comprehensive coverage of current research, including molecular interactions and simulations, phase behavior, chemical reactions in supercritical fluids, supercritical water oxidation, and forest products applications. Addresses various aspects of the supercritical water oxidation process, including fundamental kinetics and modeling, simulations of hydrogen bonding and solvation, catalysis, use of unconventional oxidants, corrosion issues, reactor design and simulation, and applications. Includes a new technique for the rapid and accurate mapping of critical curve phase boundaries.
Energy Research Abstracts
Author: Progress in Corrosion Science and Engineering II
Author: Su-Il PyunPublisher: Springer Science & Business Media
ISBN: 1441955771
Category : Science
Languages : en
Pages : 349
Book Description
This and volume no. 47 of Modern Aspects of Electrochemistry is composed of eight chapters covering topics having relevance both in corrosion science and materials engineering. In particular, the first seven chapters provide comprehensive coverage of recent advances in corrosion science.
Author: