Supercritical water oxidation (SCWO) is a rapidly emerging technology that presents potential as a hazardous waste treatment method for a wide variety of industrial chemicals ranging from common organic solvents to complex formulations such as paints, lubricating oils, and degreasers. The Naval Civil Engineering Laboratory is contributing to the development of this technology for application to waste materials generated at naval shipyards and bases. These wastes include paint stripping and changeout fluids generated from equipment service procedures as well as herbicides, pesticides, paint, and numerous other materials associated with base facility maintenance. An important design consideration in the development of SCWO systems centers on choosing a reactor operating temperature such that the destruction of the waste organic is sufficiently complete. This report examines the temperature dependence of the oxidation in supercritical water of seven common organic compounds and three industrial commercial materials over the temperature range of 430°C to 585°C and reaction times ranging from seven to thirty seconds at a pressure of 27.5 MPa (4000 psi). The materials studies are methanol, phenol, methyl ethyl ketone, ethylene glycol, acetic acid, methylene chloride, 1,1,1-tichloroethane (TCA), latex paint, motor oil, and Roundup, a commercial general purpose herbicide. The results indicate that for most materials, temperatures over 530°C and residence times near 20 seconds afford destruction efficiencies of greater than 99.95%.

Supercritical water oxidation (SCWO) is a rapidly emerging technology that presents potential as a hazardous waste treatment method for a wide variety of industrial chemicals ranging from common organic solvents to complex formulations such as paints, lubricating oils, and degreasers. The Naval Civil Engineering Laboratory is contributing to the development of this technology for application to waste materials generated at naval shipyards and bases. These wastes include paint stripping and changeout fluids generated from equipment service procedures as well as herbicides, pesticides, paint, and numerous other materials associated with base facility maintenance. An important design consideration in the development of SCWO systems centers on choosing a reactor operating temperature such that the destruction of the waste organic is sufficiently complete. This report examines the temperature dependence of the oxidation in supercritical water of seven common organic compounds and three industrial commercial materials over the temperature range of 430[degree]C to 585[degree]C and reaction times ranging from seven to thirty seconds at a pressure of 27.5 MPa (4000 psi). The materials studies are methanol, phenol, methyl ethyl ketone, ethylene glycol, acetic acid, methylene chloride, 1,1,1-tichloroethane (TCA), latex paint, motor oil, and Roundup, a commercial general purpose herbicide. The results indicate that for most materials, temperatures over 530[degree]C and residence times near 20 seconds afford destruction efficiencies of greater than 99.95%.

The objective of this study was to investigate the feasibility of using supercritical water oxidation (SCWO) to destroy organic hazardous wastes generated by Navy industrial activities. Supercritical water oxidation is the low temperature combustion of organic material in the medium of supercritical steam. The study concludes that SCWO is an economically attractive method of destroying a wide variety of hazardous organic wastes. The estimated Navy need for SCWO technology is a minimum of seven waste processing plants, each having a capacity of 1 gallon per minute of organic material. The estimated capital cost of each plant is $6M. The estimated hazardous waste disposal cost is approximately $8 per gallon of organic material, which is substantially lower than the conventional disposal cost of up to $45 per gallon. It is estimated that SCWO can be implemented on a large scale, and in a safe, reliable, and efficient manner. Waste streams that contain a large amount of mineral-acid forming chemical species or that contain a large amount of dissolved solids present a challenge to current SCWO technology.

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

Assessment of Supercritical Water Oxidation System Testing for the Blue Grass Chemical Agent Destruction Pilot Plant reviews and evaluates the results of the tests conducted on one of the SCWO units to be provided to Blue Grass Chemical Agent Destruction Pilot Plant. The Army Element, Assembled Chemical Weapons Alternatives (ACWA) is responsible for managing the conduct of destruction operations for the remaining 10 percent of the nation's chemical agent stockpile, stored at the Blue Grass Army Depot (Kentucky) and the Pueblo Chemical Depot (Colorado). Facilities to destroy the agents and their associated munitions are currently being constructed at these sites. The Blue Grass Chemical Agent Destruction Pilot Plant (BGCAPP) will destroy chemical agent and some associated energetic materials by a process of chemical neutralization known as hydrolysis. The resulting chemical waste stream is known as hydrolysate. Among the first-of-a-kind equipment to be installed at BGCAPP are three supercritical water oxidation (SCWO) reactor systems. These particular hydrolysate feeds present unique non-agent-related challenges to subsequent processing via SCWO due to their caustic nature and issues of salt management.This report provides recommendations on SCWO systemization testing inclusive of durability testing and discusses systemization testing objectives and concepts.

Supercritical Water Oxidation (SCWO) is a high pressure oxidation process that blends air, water, and organic waste material in an oxidizer in which where the temperature and pressure in the oxidizer are maintained above the critical point of water. Supercritical water mixed with hydrocarbons, which would be insoluble at subcritical conditions, forms a homogeneous phase which possesses properties associated with both a gas and a liquid. Hydrocarbons in contact with oxygen and SCW are readily oxidized. These properties of SCW make it an attractive means for the destruction of waste streams containing organic materials. SCWO technology holds great promise for treating mixed wastes in an environmentally safe and efficient manner. In the spring of 1994 the U.S. Department of Energy (DOE) initiated a Supercritical Water Oxidation Data Acquisition Testing (SCWODAT) program. The SCWODAT program provided further information and operational data on the effectiveness of treating both simulated mixed waste and typical Navy hazardous waste using the SCWO technology. The program concentrated on the acquisition of data through pilot plant testing. The Phase I DOE testing used a simulated waste stream that contained a complex machine cutting oil and metals, that acted as surrogates for radionuclides. The Phase II Navy testing included pilot testing using hazardous waste materials to demonstrate the effectiveness of the SCWO technology. The SCWODAT program demonstrated that the SCWO process oxidized the simulated waste stream containing complex machine cutting oil, selected by DOE as representative of one of the most difficult of the organic waste streams for which SCWO had been applied. The simulated waste stream with surrogate metals in solution was oxidized, with a high destruction efficiency, on the order of 99.97%, in both the neutralized and unneutralized modes of operation.