Supercritical water oxidation system

L.B. Kriksunov and A.A. Me Donald, Corrosion in Supercritical Water Oxidation Systems a Phenomenological Analysis, J. Electrochemical Society, 142, (1995), 4069. 

Kriksunov, L.B. and MacDonald, D.D., Understanding chemical conditions in supercritical water oxidation systems, ASME Heat Transfer Div., 317(2), 271-279, 1995a. 

Kriksunov LB, Macdonald DD. Corrosion in supercritical water oxidation systems—a phenomenological analysis. J Electrochemical Sci 1995 142(12) 4069, 4073. 

Residence time for supercritical water oxidation systems may be as short as several minutes at temperatures of 600 to 650°C. More than 99.9 percent conversion of EPA priority pollutants such as chlorinated solvents has been achieved in a pilot-scale plant with retention time less than 5 minutes. The system is limited to treatment of liquid wastes or solids less than 200 microns in diameter. Char formation during reaction may impact the oxidation time of the organics, while separation of inorganic salts during the process may be a problem. Typical materials for the reactor are Hastelloy C-276 and Iconel 625 (high nickel alloys), which can withstand high temperatures and pressmes and the corrosive conditions. 

Figure 12 Solubility and phase behavior in supercritical water oxidation systems, (a) O2-H2O at 250 bar (based on data from Refs. 99 and 100 at 250°C and above, other data from Ref. 101) (b) CO2-H2O at 250 bar (based on data from Ref. 102 at HO C and above, other data from Ref. 103 (c) Benzene-H2O at 250 bar (based on data from Ref. 104 below 100°C, Refs. 105 and 106 from 287-295 C, other data from Ref. 107) (d) Benzene-H2O at 100 bar (based on data from Ref. 104 up to 250°C, other data from Ref. 108). (e) NaCl-HoO at 250 bar (vapor phase compositions from Ref. 110 other data from Ref. Ill (f) NaCl-HoO at 100 bar (vapor phase compositions from Ref. 110, other data from Ref. Ill) (g) NaTStC-lCO at 250 bar (based on data from Ref. 116 at 320°C and above other data from Ref. 117) (h) Na2SO4-H2O at 100 bar (based on data from Ref. 116 at 320°C and above, other data from Ref. 117 and Ref. 118.)...

G. T. Hong, D. W. Ordway and V. A. Zilberstein, Materials Testing in Supercritical Water Oxidation Systems, First International Workshop on Supercritical Water Oxidation, Amelia Island, FL, February 1995. 

Finding (Pueblo) GA-7. Corrosion remains a serious operating problem with the GATS supercritical water oxidation system. Failure to shut down in time to replace a perforated reactor liner could result in rapid corrosion of the high-pressure reactor shell. 

Latanision, R.W. and Shaw, R.W. (1993) Corrosion in supercritical water oxidation systems Workshop Summary. MIT-EL 93-006. 

There is a background of relevant knowledge arising from the nuclear power industry and the Energy Laboratory at the Massachusetts Institute of Technology (Boston) is a centre for supercritical water corrosion studies. A workshop on Corrosion in Supercritical Water Oxidation Systems was held in May 1993. A copy of the report subsequently produced is available from Professor Latanision at MIT. 

L. B. Kriksunov, D. D. Macdonald Corrosion in Supercritical Water Oxidation Systems A Phenomenological Analysis, J. Electrochem. Soc. 142, 1995, 4069. X.Y. Zhou, S.N. Lvov, X.J. Wei, L.G. Benning, D.D. Macdonald, Quantitative Evaluation of General Corrosion of Type 304 Stainless Steel in Subcritical and Supercritical Aqueous Solutions via Electrochemical Noise Analysis , Corrosion Science, 44 (2002) 841. 

Supercritical fluid extraction — During the past two decades, important progress was registered in the extraction of bioactive phytochemicals from plant or food matrices. Most of the work in this area focused on non-polar compounds (terpenoid flavors, hydrocarbons, carotenes) where a supercritical (SFE) method with CO2 offered high extraction efficiencies. Co-solvent systems combining CO2 with one or more modifiers extended the utility of the SFE-CO2 system to polar and even ionic compounds, e.g., supercritical water to extract polar compounds. This last technique claims the additional advantage of combining extraction and destruction of contaminants via the supercritical water oxidation process."... 

T0755 Supercritical Carbon Dioxide Extraction—General T0756 Supercritical Water Oxidation—General T0770 Terra Systems, Inc., In Situ Bioremediation (ISB)... 

T0733 Sonotech, Inc., Cello Pulse Combustion Burner System T0746 STC Remediation, Inc., Solidification/Stabilization Technology T0756 Supercritical Water Oxidation—General... 

General Atomics (GA) has developed supercritical water oxidation (SCWO) systems to treat organic wastes, sludges, chemical agents, and other hazardous materials. As water is subjected to temperatures and pressures above its critical point (374.2°C, 22.1 MPa), it exhibits... 

Weatherly, Inc., developed the supercritical water oxidation (SCWO) system to treat liquid organic wastes. In February, 1999, Chematur Engineering acquired the exclusive rights to the... 

Recommendation 3-la. The Army should develop criteria and a schedule for resolving design and operational issues raised in the 1998 report, Using Supercritical Water Oxidation to Treat Hydrolysate from VX Neutralization, that have not yet been resolved for supercritical water oxidation operation at Newport. These issues include materials of construction, fabrication methods, system plugging, pressure let-down, and the duration of successful continuous pilot-scale operations. 

Lee, D.S. and Gloyna, E.E, Supercritical water oxidation microreactor system, paper presented at Water Poll. Control Fed. Specialty Conf. New Orleans, LA, April 17-19, 1988. 

Jayaweera IS, Valyashko VM. Supercritical water oxidation solubility of mixed salt systems. Manuscript in preparation, 2003. 

Most research work on the use of supercritical water has been conducted batchwise and involved non-analytical determinative applications. Thus, supercritical water oxidation (SCWO) was proposed as an alternative treatment for hazardous waste disposal [191] and also as a commercial tool for decomposing trichloroethylene, dimethyl sulphoxide and isopropyl alcohol on a pilot plant scale [192]. Current commercially available equipment (the aqua Critox" system) is usable with industrial and municipal sludge, mixed (radioactive and organic, liquid and solid) waste and military waste. This commercially available treatment has a number of advantages, namely (a) because it uses an on-site treatment method, it avoids the need to transport hazardous materials (b) it ensures complete destruction of organic wastes and allows reuse of the effluent as process water with results that meet the regulations for drinking water and (c) no licence for effluent or air emissions is needed. 

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