How hydrogen peroxide is made

The net recipe is hydrogen plus oxygen, yet the two never meet. A recycled carrier molecule passes the atoms across.

stations: 6
things upstream: 4
raw sources: 3
steps from the ground: 2

The short version

Nearly all of it comes from one looping process. An anthraquinone dissolved in solvent picks up hydrogen over a catalyst, then gives that hydrogen to oxygen when compressed air bubbles through. The peroxide is washed out of the liquid and the carrier goes back around to collect more hydrogen, cycle after cycle.

Load the carrier solution

An anthraquinone, an expensive organic molecule, is dissolved in a blend of solvents. This working solution stays in the plant permanently. The economics depend on recycling it along with the catalyst.
Hydrogenate over palladium

Hydrogen gas meets the solution over a palladium catalyst. The carrier takes on two loosely held hydrogen atoms and becomes an anthrahydroquinone.

Goes in
Hydrogen
Bubble compressed air through

Air is pushed through the loaded solution. Oxygen pulls the loose hydrogen atoms off the carrier, forming the peroxide and turning the carrier back into its starting form.

Goes in
Air
Wash the product out

The new peroxide is extracted from the organic solution. The carrier goes back to the hydrogen step, and the loop starts over.

Goes in
Water
Concentrate under vacuum

Water is removed under reduced pressure at low temperature, since the product falls apart in heat. Stronger grades are far more hazardous and need dedicated storage, so most is sold at 70% or less.
Stabilize and ship

A stabilizer goes in, the liquid is kept weakly acidic, and it travels in containers that shut out light. Light and organic matter speed its breakdown into water and oxygen. The bottle at a pharmacy holds just 3 to 6 percent.

End of the lineHydrogen peroxide Next it goes into hair dye, polyvinylpyrrolidone, wood pulp and 2 more.

Worth repeating

In its pure form hydrogen peroxide is a very pale blue liquid.
One milliliter of a 20-volume solution releases twenty milliliters of oxygen gas when it fully decomposes.
Annual production rose from 35,000 tonnes in 1950 to 2.7 million tonnes by 1998.