Corrosion inhibitors oxygen scavengers

Uses Reducing agent corrosion inhibitor wastewater treatment electrolytic plating redox reactions polymerization catalyst organic hydrazine derivs. rocket propellant corrosion inhibitor, oxygen scavenger in boiler... 

Performance of biological control formulations in the system can be affected by other chemical control programs (e.g. oxygen scavengers, some corrosion inhibitors). Oxygen scavengers and biocide formulations are usually incompatible. Widely separated injection points are advisable. 

To minimize the corrosion reactions, oxygen scavengers and corrosion inhibitors may be used as additives in solder-replacement adhesives. The percent changes in... 

Uses Corrosion inhibitor, demulsifier, pour pt. depressant, paraffin inhibitor, paraffin solvent, bactericide, scale inhibitor, oxygen scavenger, antilbamforoil and gas prod. coagulant, flocculant for water treatment fuel additive, process additive in refining... 

Oxygen Scavenger Corrosion Inhibitor Figure 10.23 Injection water treatment scheme... 

Chemical treatment programs are often individually designed for particular boiler plant systems but usually contain oxygen scavengers, pH boosters, and corrosion inhibitors. In addition, the formulations employ materials specifically designed to limit the degree of deposition and control the mechanisms of deposition. 

Where water softening is provided and there is no reduction in system water TDS, treatments are primarily based on inorganic corrosion inhibitor blends (nitrite, molybdate, etc.). Under these circumstances, there is no benefit in using an expensive organic oxygen scavenger to keep the TDS level low, and a common chemical such as catalyzed sodium sulfite may be used. 

Water losses and other problems result in periods of undertreatment of both oxygen scavengers and corrosion inhibitors and remain unexplained and uninvestigated. 

Alkalinity boosters, which are vitally necessary to enable carbonate, phosphate, balanced polymer (polymer plus phosphate or chelant), and some other program types to function, are perhaps best described as conjunctional treatments, whereas oxygen scavengers, antifoams, and condensate line corrosion inhibitors are adjuncts. Programs such as phosphate-tannin mixtures are sometimes described as adjunct treatments. The chemistries and applications of various types of conjunctional treatments and adjuncts are described in this chapter. 

Alkaline oxygen scavengers may be used as alternative treatments to some corrosion inhibitors where toxicity restrictions prohibit proprietary blends. 

A further longer term wet lay-up alternative is through the use of volatile corrosion inhibitors (VCIs) such as dicyclohexylamine acetate. These are dissolved in the water at a temperature below 60 °C, and the water is circulated for 4 to 5 hours. The boiler does not need to be completely filled because the VCI migrates to all parts of the boiler and reaches equilibrium in each of the void spaces. With traditional lay-up chemicals, the oxygen scavenger may become depleted easily (which is why the reserve usually is so high) and corrosion protection is quickly lost however, with VCI programs, there is always a volatile buffer available that maintains equilibrium and hence corrosion protection. 

Corrosion inhibitors, e.g. Ca(N02)2, which appear to act by stabilizing or otherwise altering the oxide film or by scavenging oxygen. 

Mekor . [Drew Ind. Div.] Volatile oxygen scavenger, metal passivator, corrosion inhibitor for boiler water treatment... 

OTHER COMMENTS used as a chemical intermediate in the preparation of higher bo-ranes, alkyl boranes, ethyl pentaborane, and various hydrides useful as jet and rocket fuels, catalysts, corrosion inhibitor fluxing agents, and oxygen scavengers. 

A water system naturally contains sulfate-based compounds, but when sulfite is added to a closed water system as an oxygen scavenger and corrosion inhibitor, the sodium sulfite is oxidized to sodium sulfate, as indicated in Equation 18.1 (Yuzwa 1991) ... 

Steam condensate may be contaminated in the process, and it usually contains some level of treating chemicals that include corrosion inhibitors, neutralizing agents, and oxygen scavengers. 

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