The peroxide process is a method for producing hydrazine, a highly reactive and unstable molecule of nitrogen and hydrogen. It has the chemical composition N2H4. Hydrazine is used as a chemical intermediate for producing a wide range of chemicals, for blowing foams used in flooring and automotive seats, and as a rocket propellant.
Hydrogen peroxide reacts with ammonia in the peroxide process. This reaction is typically performed in the presence of a ketone such as acetone or methyl ethyl ketone. Different intermediate chemicals are produced depending on the ketones used. All result in the formation of hydrazine, water and the ketone, which can be recycled in the process.
The original process for producing hydrazine was the Raschig process, named for German chemist Friedrich Raschig. Hydrazine was first synthesized in the late 1880s. Raschig processes use a reaction of ammonia with sodium hypochlorite, or bleach, to form an intermediate chemical called chloramine. A second reaction of chloramine with more ammonia and sodium hypochlorite creates hydrazine. This process became less popular because of large quantities of salt created as a byproduct, which can create potential disposal issues.
The peroxide process is more environmentally benign because no salt is created during the production of hydrazine. In addition, the ketone necessary for the reaction is re-created as a byproduct and can be recycled back to the beginning of the process. Ketones also do not mix with the hydrazine and water solution from the reaction, which makes separation a much simpler task in the peroxide process.
A highly reactive chemical, hydrazine is useful as a chemical intermediate and as a rocket propellant. For over two decades beginning in the 1950s the bulk of hydrazine production was used for rocket propellant, as countries developed space launch technologies. Hydrogen peroxide can also be used to propel rockets. The energy developed from hydrazine, however, is much greater than hydrogen peroxide, so rocket systems used hydrazine more frequently.
Hydrazine is widely used as a chemical intermediate to produce foaming agents. Foaming agents are used to create foams for vinyl flooring and automotive seat cushions, with several other uses. Hydrazine is rarely used directly in producing commercial or consumer products, however, due to its instability and high toxicity.
Oxygen can be a contaminant in some chemical reactions. Hydrazine can be used as a gas scavenger, which will react rapidly with any trace quantities of oxygen in a system. Scavengers are also useful in removing contaminants that can cause corrosion of process equipment and piping. Hydrazine is also an important component of agricultural fertilizer and herbicide production, and is used in commercial water treatment. Medical research and cancer treatments have shown success using products derived from hydrazine.