Supercritical water oxidation study

D. D. Macdonald, et at, Supercritical Water Oxidation Studies Understanding the Chemistry and Electrochemistry of SCWO Systems , Pennsylvania State University Pinal Report to the US Army Research Office, Grant Nos. DAAL 03-92-G-0397 and DAAH 04-93-G-0150, Feb. 1997. 

S. H. Timbedake, G. T. Hong, M. Simson, and M. ModeU, "Supercritical Water Oxidation for Wastewater Treatment Preliminary Study of Urea... 

The two fluids most often studied in supercritical fluid technology, carbon dioxide and water, are the two least expensive of all solvents. Carbon dioxide is nontoxic, nonflammable, and has a near-ambient critical temperature of 31.1°C. CO9 is an environmentally friendly substitute for organic solvents including chlorocarbons and chloroflu-orocarbons. Supercritical water (T = 374°C) is of interest as a substitute for organic solvents to minimize waste in extraction and reaction processes. Additionally, it is used for hydrothermal oxidation of hazardous organic wastes (also called supercritical water oxidation) and hydrothermal synthesis. 

Foster Wheeler. 2001. Supercritical Water Oxidation (SCWO) Engineering Design Studies II—TW—SCWO GB Campaign Operability Draft Test Report, December 31. Livingston, N.J. Foster Wheeler Development Corporation. 

M. J. Cocero, T. Sanz., F. Fdez-Polanco, Study of Alternatives for the Design of a Mobile Unit for Wastewater Treatment by Supercritical Water Oxidation, J. Tech. Biotech, (in press). 

Reviewed previous SCWO research with model pollutants and demonstrated that phenolic compounds are the model pollutants studied most extensively under SCWO conditions Studied supercritical water oxidation of aqueous waste Explored reaction pathways in SCWO of phenol Studied catalytic oxidation in supercritical water Explored metal oxides as catalysts in SCWO Studied decomposition of municipal sludge by SCWO Investigated the SCWO kinetics, products, and pathways for CH3- and CHO-substituted phenols Determined oxidation rates of common organic compounds in SCWO... 

To date, numerous model compounds simulating the pollutants in common waste streams have been studied under laboratory-scale conditions by many researchers to determine their reactivities and to understand the reaction mechanisms under supercritical water oxidation conditions. Among them, hydrogen, carbon monoxide, methanol, methylene chloride, phenol, and chlorophenol have been extensively studied, including global rate expressions with reaction orders and activation energies [58-70] (SF Rice, personal communication, 1998). 

Timberlake SH, Hong GT, Simson M, Modell M. Supercritical water oxidation for wastewater treatment preliminary study of urea destruction. SAE Tech, Paper 820872, Society of Automotive Engineers, Inc., Warrendale, PA, 1982. 

G. T. Hong, P. K. Fowler, W. R. Killilea and K. C. Swallow, Supercritical Water Oxidation Treatment of Human Waste and System Configuration Tradeoff Study, SAE Technical Paper, No. 871444, 1987. 

The October 8, 2007, CDCAB resolutions on treatment of noncontaminated rocket motors repeated the board s earlier position indicating potential support for either offsite recycling at a government facility or treatment at the planned BGCAPP supercritical water oxidation (SCWO) facility. The resolutions also supported study of the use of the static detonation chamber for noncontaminated rocket motors only (CDCAB, 2007). 

The performance of the new analytical method was adequate to ensure that measured GB concentrations in the hydrolysate were low enough for secondary treatment using supercritical water oxidation (SCWO). Method detection limit (MDL) values in hydrolysate were 2.2 pg/L (2.2 ppb) with 68 percent recovery and were calculated in accordance with standard U.S. Environmental Protection Agency (EPA) methods (40 CFR Part 136, Appendix B). This value is well below the release criteria of 75 ppb for GB in the hydrolysate. A more significant performance parameter is the target action limit (TAL), which is the concentration for which 95 percent of the measurements will be below the release criteria (Malloy et al., 2007). In an analysis of GB performed on hydrolysate generated from two batch reactor studies conducted at Battelle, the TAL values were calculated at 57 ppb and 52 ppb. 

Supercritical water oxidation (SCWO) technology has been studied as an alternative method for destroying hazardous waste, or converting it into harmless ... 

The oxidation of harmful organic compounds contained in aqueous waste effluents known as Supercritical Water Oxidation (SCWO) has been investigated since the 1980s (reviews 83, 89]). These studies are based on very fundamental work concerning the properties of supercritical water [2j and on pioneering experiments [90, 91] concerning conversions in supercritical water. 

In addition to the investigation of numerous model compounds, real wastes from chemical, pharmaceutical and food industry, from municipal sewage treatment plants, and from military and nuclear power facilities were tested in bench and pilot scale plants [110]. For a better understanding of supercritical water oxidation, single components like 2,4-dinitrotoluene, acetic acid, ammonia, aniline, cyanide, dichloromethane, ethanol, formic add, hexachlorocydohexane, hydrogen, phenol, PVC, DDT, pyridine, thiophene, toluene, trichloroethylene, and 1,1,1-trichloroethane were studied. From these experiments, kinetic data were obtained. The destruction efficiency, which is the ratio between the residual total organic carbon content (TOC) and the initial TOC achieved for these compounds is up to 99.999 % [83]. Also flames in supercritical water, e.g. by oxidation of methane with oxygen, have been studied [111, 112]. 

Studies of the extraction of pollutants from soils, sediments, sludges and other matrices have been carried out extensively on a laboratory scale. In some cases degradation of the extracted compounds occurs during the process. In other studies, a degradation step, such as supercritical water oxidation, has been added in-Hne to... 

General Atomics. 1997. Supercritical Water Oxidation Corrosion Studies Technical Report, Vols. 1 and 2. Aberdeen Proving Ground, Md. Program Manager for Assembled Chemical Weapons Assessment... 

Supercritical fluid, especially supercritical water (SCW), that is above the thermodynamic critical point of water (374"C, 22.1 MPa), has attracted increasing attention in various applications, such as in supercritical water oxidation (SC WO), in supercritical water gasification (SCWG), and for the continuous synthesis of nanoparticles. The environment of reactors presents a big challenge for structural materials used in the components. Many kinds of materials including stainless steel, alloys, and ceramics have been studied for using in SCW atmosphere. However, the details of the corrosion mechanism of each ceramic in an SCW environment were not fully clarified. 

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