What Is Hydrazine?
Hydrazine, also known as diamine or diamide, is a colorless, fuming liquid with an ammonia-like odor. It has the chemical formula N2H4, a density of 1.013 g/cm3, a boiling point of 114°C, and a melting point of 2.0°C. Hydrazine is highly reactive and a powerful reducing agent, soluble in water and hygroscopic, forming hydrazine hydrate (N2H4・H2O) in air. It is toxic and carcinogenic.
Uses of Hydrazine
Hydrazine serves as a propellant in rocket engines and for attitude control in artificial satellites and space probes. It’s also used in the production of soft and rigid foam, fuel cells, fungicides, herbicides, and pesticides. Hydrazine hydrates are utilized in plastic foaming agents, oxygen scavenging, decarbonation, pH adjustment, polymerization catalysts, boiler water treatment, and iron removal from wastewater.
Methods of Producing Hydrazine
1. Peroxide Process (Pechiney-Ugine-Kuhlmann Process):
Ammonia and hydrogen peroxide are reacted in the presence of a catalyst, producing no salts as a byproduct.
2. Olin Raschig Process:
Monochloramine, formed from sodium hypochlorite and ammonia, reacts with ammonia to produce hydrazine, yielding NaCl as a byproduct.
3. Bayer Ketazine Process:
This process industrialized before the peroxide process, involving the reaction of sodium hypochlorite and ammonia in acetone.
Effects on Humans
Acute exposure to hydrazine affects the central nervous system, liver, and kidneys. It can cause skin and eye irritation, and allergic contact dermatitis.