Hydrazine water treatment using

Oxygen scavengers other than hydrazine are also used, especially catalyzed sodium sulfite, which reacts rapidly with oxygen even at room temperatures to form sodium sulfate. Catalyzed hydrazine formulations are now commercially available that react with oxygen at ambient temperatures at rates comparable to catalyzed sulfite (189). At elevated temperatures, the reaction rates are all similar. Table 14 Hsts the standard hydrazine solution products offered by Olin Corp. for sale to the water-treatment market. Other concentrations are available and other companies offer similar products. 

In the recommendations for very high pressure and supercritical boilers, McCoy notes that because only volatile chemicals can be used for water treatment above 2,500 psi, hydrazine alone is added to the FW at 150 to 200% of the concentration of oxygen, which should be less than 5 ppb. 

Acyclic ADC compounds, which are more correctly named as derivatives of diazene, are generally prepared from hydrazine derivatives. For example, diethyl azodicarboxylate (Chemical Abstracts name diethyl diazene-1,2-dicarboxylate)5 is prepared from hydrazine by treatment with ethyl chloro-formate followed by oxidation with chlorine in benzene-water.6 Other oxidants which have been used include JV-bromosuccinimide,7 nitric acid,8 inorganic nitrates,9 potassium dichromate,10 silver carbonate on celite,11 and phenyl iodosotrifluoroacetate.12 The hydrazine derivative may also be... 

Production of hydrazine and its use as a chemical intermediate, reducing agent, rocket fuel and boiler-water treatment agent may result in its release to the environment through various waste streams. Hydrazine is also naturally produced by Azotobacter agile during nitrogen fixation. It has been detected at low levels in wastewater samples (United States National Library of Medicine, 1997). 

Hydrazine achieved prominence initially as a rocket fuel, but ulso I mds wide-range use in fuel cells, agricultural chem-icnls, boiler water treatment, and blowing agents. It is produced by the reaction of sodium hypochlorite with either ammonia or urea. 

Uses. Hydrazine is used directly as an oxygen scavenger and as an energy source. Hydrazine is consumed in the following applications blowing agents (33%), pesticides (32%), water treatment (18%) and miscellaneous (17%).128... 

Hydrazine, N2H4, is a colorless liquid with a weakly ammoniacal odor. Its density, boiling point (114°C), and melting point (2°C) are fairly close to those of water. Hydrazine and its monomethyl and dimethyl derivatives are used as rocket fuels. A more mundane application of hydrazine is its use in water treatment and in cleaning steam boilers. 

Copper nitrate trihydrate (Cu(N03)2-3H20) and hydrazine hydrate (N2H4 H2O) were both analytical reagent (A.R.) grade, and sodium stearate (CH3(CH2)i6COONa) was a chemically pure (C.P.) reagent. These were purchased and used without further treatments. Distilled water was used as the solvent. 

Hydrazine and its derivates are used as blowing agents for plastic foams, boiler water treatment, polymerization initiators, pesticides, pharmaceuticals, and dyes. 

The uses of inorganic derivatives of hydrazine as explosives and propellants (energetic materials), oxygen scavenger (boiler water treatment) and analytical reagents, and so on, although known, are not well documented. Some of these applications are discussed in this chapter. 

For once-through boilers, the treatment must be without soHd residues, so all-volatile treatment (AVT) is used. AVT, which is also used in some dmm boiler systems, rehes on the feedwater chemical additives, ammonia and hydrazine, to provide water appropriate to the boiler. Because the additives are volatile, they do not accumulate in the boiler and provide only minimal protection during contaminant ingress. Most plants using AVT have some form of condensate poHsher to remove impurities from the condensate. 

Supercritial boilers use all-volatile treatments, generally consisting of ammonia and hydrazine. Because of the extreme potential for deposit formation and steam contamination, no soHds can be tolerated in supercritical once-through boiler water, including treatment soHds. 

Chloramine was widely used in the treatment of water supplies between 1930 44 but many water plants have abandoned this treatment to-day. It has bactericidal props, but against many organisms its action is much weaker than free chlorine. This compd can react, under alkaline condition, with excess ammonia to form hydrazine Refs l)Gmelin, SystNr 6(1927), 418ff 2)... 

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