Titanium, hydrogen peroxide corrosion

Corrosion can be a problem, especially if a chlorine-containing compound is decomposed. This may require that the reactor be made of titanium. The corrosion can be reduced by the use of sodium carbonate.207 Use of this system at 380°C reduced the content of polychlorinated biphenyls in a sample from 20 mg/L to less than 0.5 /tg/L. Trichloroethylene, 1,1,1-trichloroethane, and trichloroacetic acid were destroyed with 99.96% efficiency at 450°C for 60 ss using 1.5% hydrogen peroxide plus sodium bicarbonate.208 Sodium nitrate or sodium nitrite could be used in place of the hydrogen peroxide. Nitrates, ammonium hydroxide, and amines, all are converted to nitrogen at 350-360 C. Emulsions of petroleum, water, and solids can be broken by heating to 350oC. Supercritical water has been used to recover 2,4-diamino-toluene from distillation residues from the manufacture of 2,4-toluenediisocyanate.209... 

Because the corrosion resistance of titanium is based on the formation of an oxide film, the presence of oxidizing species in the acidic solution will promote the formation of a passive film and therefore reduce the rate of corrosion of the alloy. A minimum amount of the oxidizing species is needed to promote the formation of the oxide film. Some oxidizing species, e.g. hydrogen peroxide, do not seem very effective at main-... 

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