What is wet oxidation?

Wet oxidation is a chemical process for removing organic contaminants from wastewater flows. The process includes heating contaminated water to high temperatures and air injection at high pressures. Air reaction with contaminants oxidizes them to conventional gases, such as carbon dioxide, which are later separated from the water stream.

air introduction at lower pressure into watercourses creates an agitation effect, but even at higher temperatures it will only respond with any organic contaminants. Increasing pressure above the critical point of water, where water molecules are neither liquid nor couples, create a single phase in the introduction of air. The air will respond very well with organic materials and a later step where pressure is reduced, removes any remaining air and gases created by reaction. This point is about 3206 PSIA (221 bar) and 705 ° F (374 ° C). Above this point, water is known as a supercritical fluid and oxidative reactions often occur under these conditions.

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alternative process that allows the use of lower temperatures and pressures is performed with the catalytic converter. The waste stream is air pressure and passes a suitable catalyst that may vary depending on contamination. The catalyst helps the chemical reaction between air and organic materials, but the reaction is not consumed or destroyed. Catalytic oxidation reactions of wet wet may occur in sub-critical conditions that can reduce operating costs and use vessels with lower pressure.

The materials of the design for reactors and the related devices used for wet oxidation must be selected carefully. High temperatures can weaken many metals, which may endanger their Strength to contain the necessary pressures. Some organic contaminants create an acidic compound during the reaction and many metals will not be suitable for corrosion protection. Pressure heated air can oxidize and weaken the materials used for sealants and seals and mustTailed attention to the selection of inert materials that will withstand serious operating conditions.

As a result of high pressures and temperatures needed for wet oxidation reactions, the preheating of air and waste water streams can improve energy efficiency. Thermal exchangers can be used to use high temperature fluids and leave the reactor to preheat air and water streams. In response of air with organic substances, further heat may occur and the use of this heat can reduce the operating costs of the system.