Anthraquinone method

The anthraquinone process is a method for the production of hydrogen peroxide that goes back to the AO process at IG Farben .

Procedure

In principle, technical production using this process is based on the reduction of oxygen , as is the case with direct synthesis from the elements. Instead of the hydrogen itself, however, a 2-alkyl anthrahydroquinone (for example 2-ethyl anthraquinone ) is used, which was previously prepared from the corresponding 2-alkyl anthraquinone by catalytic hydrogenation with palladium , which with oxygen in the organic phase with regression of the anthraquinone reacts to hydrogen peroxide. The alkyl groups (R-) used include ethyl and tert- butyl .

The hydrogen peroxide is then extracted with water and separated from the water by fractional distillation . The hydrogen peroxide accumulates in the residue. Since anthraquinone is formed again in the last step, it is not consumed and therefore has a catalytic effect. The gross response is therefore:

${\displaystyle \mathrm {H_{2}+O_{2}\longrightarrow H_{2}O_{2}} }$

By using ozone instead of oxygen, this process can also produce dihydrogen trioxide . The choice of solvents is problematic, since they have to dissolve both the quinone and hydroquinone forms of the catalyst, but at the same time have to be as insoluble in water as possible, non-volatile and chemically inert with regard to the reaction. Because of this problem, for example, by-products are formed, in particular during hydrogenation.

Individual evidence

1. ↑ Entry on hydrogen peroxide. In: Römpp Online . Georg Thieme Verlag, accessed on June 8, 2014.
2. ^ Christoph Janiak: Non-metal chemistry . 4th edition. Shaker Verlag, Aachen 2012, ISBN 978-3-8440-1042-8 , p. 121 .