US1138520A - Process of manufacturing peroxid of hydrogen. - Google Patents

Description

WALTER WEBER, 0F DUSSELDORF, GERMANY, ASSIGNOR T0 THE FIBM CIE., 0F JD'USSELIDORF, GERMANY.

OF HENKEIQ &

PROCESS OF MANUFACTURING PEROXID OF HYDROGEN.

No Drawing.

To all whom it may concern.

Be it known that I, WALTER WEBER, a citizen of the German Empire, and residing at Dusseldorf, Germany, have invented a certain new and useful Improved Process of Manufacturing Peroxid of Hydrogen, of which the following is a specification.

In the copending patent application Serial No. 766,091 of May7, 1913, a process of cathodically making peroxid of hydrogen in an electrolyte containing oxygen or oxygenous gases has been described, in which these gases have been supplied and the electrolysis itself has been brought about at a pressure above atmospheric. In this process amalgamated gold cathodes were used. I have found that besides being very expensive the use of these gold cathodes is connected with certain disadvantages, and I have succeeded by further experiments in finding that these defects can be obviated when cath odes of a different kind are employed.

I have found that I can continuously carry into practice the cathodic manufacture of peroxid of hydrogen, c. e. that I can save the re-amalgamation of the cathodes requisite under certain conditions at certain intervals of time when the expensive cathode of gold amalgam is used, when I employ instead of this expensive cathode of gold amalgam a cheaper cathode material, such as silver amalgam, i. c. a compound of silver and mercury, or an amalgamated silver.

cathode.

Owing to using the cathode of silver amalgam instead of the cathode of gold amalgam I materially reduce the cost of the process of making-peroxid of hydrogen and I also obtain a'better yield.

Example: I separate the anode chamber and the cathode chamber in a suitable electrolyte, e. g. the aqueous solution of a mineral acid, by a diaphragm of asbestos from one another and insert an amalgamated silver cathode or a cathode composed of silver I amalgam. I then saturate this electrolyte at apressure of 100 atmospheres with oxygen or with a gas containing oxygen and electrolyze under pressure. It is not necessary to employ absolutely pure oxygen, since Specification of Letters Patent.

Patented May a, 1915.

Application filed February 26, 1914. Serial No. 821,217.

the desired results may be obtained with a gas containing a small proportion of oxygen such, for example, as air. When a high current density of, e. 9., 5 'amperes per square centimeter is used I find that 2 volts sufiice, as the saturation of. the electrolyte with oxygen under pressure diminishes the voltage of decomposition. The oxygen or the gascontaining oxygen must be both supplied into and distributed or dissolved in the electrolyte under pressure, and care must be taken that the electrolyte is always at a pressure materially higher than that of the at mosphere. Instead of the mineral acid, 6. g.

sulfuric acid, solutions of alkalis or earth' alkalis or directly alkaline solutions may be used which contain free'alkali or earth alkali. The result is not so good, however, as when mineral acid is employed. When less value is attached to the purity of the peroxid of hydrogen obtained than to high eficiency it is preferable to employ stabilizing admixtures, such as boracic acid or urea, which, as is known, are able to retard the catalytic decomposition of the peroxid of hydrogen.

I claim a y 1.- A process of making hydrogen peroxid which comprises reducing oxygen or oxygenous gases. dissolved in a suitable electrolyte to hydrogen peroxid at a cathode com- 1ng oxygen or oxygenous gases into'the watery solution of a suitable electrolyte under high pressure and during the simultaneous generation of hydrogen at a cathode composed of silver amalgam by electrolysis.

In testimony whereof, I afiix my signature in. the presence of two witnesses.

WALTER WEBER. [n s.] Witnesses: A