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Hydrogen peroxide is manufactured today almost exclusively
by the autoxidation of 2-ethyl-9,10-dihydroxyanthracene (C16H14O2) to
2-ethylanthraquinone (C16H12O2) and hydrogen peroxide using oxygen from the air.
This is known as the Riedl-Pfleiderer process.
In this reaction, the hydroxy groups on the middle ring of
anthracene are deprotonated and are turned into ketones, while two double bonds
are lost from the middle ring and are replaced as C=O double bonds in the ketone
groups. The anthraquinone derivative is then extracted out and reduced back to
the dihydroxy compound using hydrogen gas in the presence of a metal catalyst.
The overall equation for the process is deceptively simple:
H2 + O2 → H2O2
However the economics of the process depend on
effective recycling of the quinone and extraction solvents, and of the
Formerly inorganic processes were used, employing the
electrolysis of an aqueous solution of sulfuric acid or acidic ammonium
bisulfate (NH4HSO4), followed by hydrolysis of the peroxydisulfate ((SO4)2)2−
which is formed.
In 1994, world production of
H2O2 was around 1.9 million tonnes and grew to 2.2 million in 2006, most of
which was at a concentration of 70% or less. In that year bulk
30% H2O2 sold for around US $0.54 per kg, equivalent to US $1.50 per kg (US
$0.68 per lb) on a "100% basis".