Supercritical water oxidation designs

Figure ES-2 is a block diagram of the Eco Logic technology process. The primary treatment destroys the agent and the energetic materials by hydrolysis with caustic or water. Flowever, the hydrolysis products (hydrolysates) must be further treated prior to final disposal. For this secondary step, Eco Logic proposes to use a transpiring-wall supercritical water oxidation (SCWO) reactor design. The following major operations are included ...

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. 

Foster Wheeler Development Corporation (FWDC) has designed a transportable transpiring wall supercritical water oxidation (SCWO) reactor to treat hazardous wastes. As water is subjected to temperatures and pressures above its critical point (374.2°C, 22.1 MPa), it exhibits properties that differ from both liquid water and steam. At the critical point, the liquid and vapor phases of water have the same density. When the critical point is exceeded, hydrogen bonding between water molecules is essentially stopped. Some organic compounds that are normally insoluble in liquid water become completely soluble (miscible in all proportions) in supercritical water. Some water-soluble inorganic compounds, such as salts, become insoluble in supercritical water. 

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). 

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. 

Barnes CM. Evaluation of tubular reactor designs for supercritical water oxidation of U.S. Department of Energy mixed waste. INEL-94/0223, Lockheed Idaho Technologies Co., Idaho Falls, ID, 1994. 

Supercritical Water Oxidation (SCWO) has been proved to be a suitable process for treatment of several toxic and hazardous organic wastes due to its high removal efficiency. SCWO requires of hard reaction conditions (22.1 MPa and over 374°C). Special reactors are needed to support these conditions. An original reactor design is presented here wich has been tested in the treatment of alcohols+ammonia solutions in water. Performance results are presented here for ammonia and alcohols. Destruction efficiency greater than 99.9% are reached for both compounds, probing the correct performance of the reactor. 

C. M. Barnes, Evaluation of Tubular Reactor Designs for Supercritical Water Oxidation of U.S. Department of Energy Mixed Waste, Idaho National Engineering Laboratory Report INEL-94/0223, December, 1994. 

C. M. Barnes and C. H. Oh, Chemical Reactor Design for Supercritical Water Oxidation of U.S. DOE Waste, First International Conference on Advanced Oxidation Technologies for Water and Air Remediation, London, Ontario, Canada, June 25-30, 1994. 

The same equipment can be used as in PLE, but for temperatures above 200°C, there is no commercial equipment available and specially designed or home-built insmiments are therefore used. Chematur in Sweden manufactures industrial-scale supercritical water oxidation plants operating at temperatures above 400°C (Aqua Critox ). It is possible that such equipment can be modified to subcritical water extraction processes. Uhde in Germany probably also has industrial-scale solutions for PHWE. 

The facility will be designed to operate 8 hours a day, 5 days a week. At this time no specific rate has been determined for the disposal of the binaries, the CAIS items, or the chemical samples. The facility will include a munition unpacking chamber, two ECCs, a neutralization trailer, soak tanks, and a secondary waste processor. The secondary waste processors under primary consideration are supercritical water oxidation and plasma arc, with the Army favoring... 

Recommendation (Demo I) GA-2. Before construction of a full-scale supercritical water oxidation (SCWO) system, additional evaluations of constraction materials and fabrication techniques will be necessary because corrosion and plugging prevent continuous operation with the present design. If the new construction materials do not solve these problems, then alternative SCWO reactor designs should be investigated. 

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