How Is Hydrazine Made?

Hydrazine, a component of rocket fuel, is a simple substance made up of two nitrogen atoms and four hydrogen atoms. Ammonia, another simple substance with one nitrogen atom and three hydrogen atoms, is the starting point for the synthesis of hydrazine.

Olin Raschig Process

• In the Olin Raschig process, an aqueous solution of sodium hypochlorite (NaClO) and ammonia produce chloramine, a substance containing nitrogen, hydrogen and chlorine, at a temperature of 41 degrees F. Then at 266 degrees F, chloramine unites with more ammonia to produce hydrazine. It is then necessary to separate the hydrazine from the other reactants by a physical process called fractional distillation.

P.J. Schestakov Synthesis

• In the Schestakov synthesis, urea reacts with sodium hypochlorite and sodium hydroxide. The products are hydrazine, sodium chloride, sodium carbonate and water.

Bayer Process

• In the Bayer process, chloramine and ammonia unite to form a substance from which hydrazine can be made easily. Acetone or some similar oxygen-containing substance helps the reaction along but remains unchanged in the end.

Other Processes

• Some processes use hydrogen peroxide in the production of hydrazine. Another especially clean process has no chlorine compounds as reactants. It produces hydrazine from benzophenone azine, a more complex substance that has two nitrogen atoms bonded together in the center of the molecule. It is a fairly easy chemical process to remove these two nitrogen atoms from their molecule and convert them into hydrazine.