MODAR

Work on SCWO process development was performed in the early 1970s and in the 1980s, many of the developments were performed under private contract to industrial or federal agencies. The technology for waste treatment and generation of energy from waste or low grade materials was commercialized by Modar (Natick, Massachusetts). 

The demonstration unit was later transported to the CECOS faciHty at Niagara Falls, New York. In tests performed in 1985, approximately 3400 L of a mixed waste containing 2-chlorophenol [95-57-8] nitrobenzene [98-95-3] and 1,1,2-trichloroethane [79-00-5] were processed over 145 operating hours 2-propanol was used as a supplemental fuel the temperature was maintained at 615 to 635°C. Another 95-h test was conducted on a PCB containing transformer waste. Very high destmction efficiencies were achieved for all compounds studied (17). A later bench-scale study, conducted at Smith Kline and French Laboratories in conjunction with Modar (18), showed that simulated chemical and biological wastes, a fermentation broth, and extreme thermophilic bacteria were all completely destroyed within detection limits. 

SC WO [supercritical water oxidation] A generic name for processes which destroy organic wastes in water by oxidation under supercritical conditions. The first such process was MODAR, invented in 1980. Since then, several other companies have introduced competing processes. 

T0329 General Atomics, MODAR Supercritical Water Oxidation... 

In 1990, Thomason estimated the cost of operating a SCWO facility based on results of MODAR pilot-scale studies and plans for a commercial facility. The primary factors influencing costs of a SCWO unit were the treatment capacity of the facility and the organics concentration of the feed material (D11985R, p. 41). MODAR technology was recently acquired by General Atomics. 

MODAR Inc. (Massachusetts. USA) developed the first reactor vessel [13]. It comprised an elongated, hollow cylindrical pressure-vessel, capped at both ends so as to define an interior reaction chamber. Defined within the reaction chamber are a supercritical temperature zone, in the upper region of the reactor vessel, and a subcritical temperature zone in the lower region of the reactor vessel. Oxidation of organics and oxidizable inorganics takes place in the supercritical temperature zone. Dense matter, such as inorganic material initially present and formed by reactions, if insoluble in the supercritical-temperature fluid, falls into the liquid phase provided in the lower-temperature, subcritical zone of the vessel. A perimeter curtain of downward-flowing subcritical-temperature fluid is established about a portion of the interior of the cylindrical wall of the vessel to avoid salt-deposits on the walls of the reactor vessel. 

MODAR, Co (2) shipboard waste treatment using a novel reactor design [123,126] by Foster Wheeler and General Atomics, and (3) treatment of PCB waste streams containing very low levels to 100% concentration [125] by MHI. 

Table 4 Selected Results of MODAR Pilot Demonstration in Niagara Falls...

Thomson B, Hong GT, Swallow KC, Killilea WR. The MODAR supercritical oxidation process. In Freeman HM, ed. Innovative Hazardous Waste Treatment Technology Series, 1 31 42. 

Fig. 1 Principles of the most outstanding SCWO reactor configurations a) tubular reactor developed at the university of Austin, Texas / /, commercialized by EWT, operated in Huntsville,Texas 111, capacity 5 gpm b) vessel reactor, MODAR Inc., Massachusetts /3/ c) transpiring wall reactor, Summit Research Corp., Santa Fe, New Mexico /4/ filmcooled coaxial hydrothermal burner developed at the ETH Zurich, Switzerland 15/...

Experiments in our tubular SCWO reactors are described in [1], A model for SCWO in a Modar vessel reactor was published recently [2]. This paper will describe our present work on a model for tubular flow SCWO reactors. Some numerical simulation results will demonstrate the use of the model to understand time dependent temperature instabilities. The paper also presents first results to derive process parameters from operational process data. 

One approach to reduce corrosion and plugging is to cool the walls and to install a recirculation zone, which sustains the reaction via cold feed injection, i.e. the feed is injected at temperatures of 300 to 500 K. The MODAR Reverse Flow Reactor as proposed in [3] shows these features for the first time, although the reverse flow is primarily employed to separate solids. 

Jacobs G. P. et al., Utilization of Phoenics in the design of the MODAR SCWO reactor, Presentation in session " Reactions in supercritical fluids", 1992 Annual AICHE Meeting, Miami Beach, FL, nov. 1992... 

Modar is also the trade name for a range of acrylic resins and the name of a maker of modular architectural components. 

S modarate (aptat.-wma viauhl chj. Mpnssnio Lustrex 50.G mm diam. disc... 

Swallow, K.C. Killilea, W.R. Malinowski, K.C Staszak, C.N. The Modar process for the destruction of hazardous organic wastes—field test of a pilot-scale unit. Waste Manag. (Amsterdam, Netherlands) 1989, 9 (1), 19-26. 

Building on the results of these initial studies, Modell began adding oxygen in order to explore the effect of the supercritical water environment on oxidation reactions of organic species. In 1980, he started MODAR as the first company established to develop and commercialize the SCWO process. Many of the characteristic attributes that are commonly associated with SCWO were first discovered and described by personnel at MODAR, and they established an... 

MODAR, Inc. 1980-1996" Vertical reverse flow vessel Organo Corp. 

A second full-scale SCWO plant in operation in Japan was built by Organo Corp, to treat laboratory wastewater at a national university. This plant is based on the MODAR design and has been operating since 2002. ... 

For many of the metallic constituents, the product form in the SCWO liquid effluent is dependent to some degree on pH. As the liquid effluent is near ambient temperature, general chemistry rules may be applied. Acidic conditions can lead to higher dissolved levels of certain metals. A common example is provided by nickel, which forms nickel oxide in the SCWO reactor due to feed oxidation or corrosion. When excess hydrochloric or sulfuric acid is present in the SCWO effluent, some of the nickel oxide dissolves to yield dissolved nickel. Many of the entries in Table 14 have not been reported in the literature, but are based on unpublished observations by MODAR and General Atomics. 

DSI (not Texas Various chemical Modar RCRA Subpart B 1987 General Atomics... 

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