Supercritical water oxidation or SCWO is a process that occurs in water at temperatures and pressures above a mixture's thermodynamic critical point.
Under these conditions water becomes a fluid with unique properties that can be used to advantage in the destruction of hazardous wastes such as PCBs.
The fluid has a density between that of water vapor and liquid at standard conditions, and exhibits high gas-like diffusion rates along with high liquid-like collision rates.
In addition, the behavior of water as a solvent is altered (in comparison to that of subcritical liquid water) - it behaves much less like a polar solvent.
As a result, the solubility behavior is "reversed" so that chlorinated hydrocarbons become soluble in the water, allowing single-phase reaction of aqueous waste with a dissolved oxidizer.
The reversed solubility also causes salts to precipitate out of solution, meaning they can be treated using conventional methods for solid-waste residuals.
Efficient oxidation reactions occur at low temperature (400-650 °C) with reduced NOx production.
SCWO can be classified as green chemistry or as a Clean Technology.
The elevated pressures and temperatures required for SCWO are routinely encountered in industrial applications such as petroleum refining and chemical synthesis.
[This introduction is quoted from Wikipedia]
Here are some links for further readings:
A simpler description of SWOT here
Over View of Supercritical Water Oxidation Technology
Wastes Treatable by the Technology
Advantages of the Transpiring-Wall SCWO Reactor & Closed-Cycle SCWO Processing System
A few disadvantages of the reactor
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