Enichem finds low-cost hydrogen peroxide process
15 Jan 2000
A process to manufacture hydrogen peroxide from carbon monoxide could provide a plentiful and low-cost source for this product, according to Enichem.
The process starts with a solution of trichlorobenzene, n-butanol and pentafluoroctanoic acid in water. This contains a catalyst palladium acetate and 2,9-dimethyl-4,7-diphenylanthraquinone. This is pumped into a reactor, where it sits under a mixture of carbon monoxide and oxygen, kept at moderate temperature and high pressure.
The process works by oxidising the carbon monoxide to carbon dioxide. The oxygen 'splits' by an unknown mechanism, with one atom going to the CO and the other to the water in the aqueous solution. On emerging from the reactor, the solution contains 2.8 per cent hydrogen peroxide by weight. The process can be operated on a semi-continuous basis, says Enichem; this produces about 0.04kg of hydrogen peroxide per litre of aqueous solution per hour.
Hydrogen peroxide is currently made by an autoxidation process, which involves the cyclic oxidation and reduction of an alkyl anthraquinone solution. The quinone is converted to a quinol by reaction with hydrogen; subsequent reduction reacts this hydrogen with oxygen to form the peroxide. Although this produces a more concentrated solution than the Enichem process, the quinones are very expensive and suffer losses through the process cycles.
