US1543357A - Process for the recovery of hydrogen and oxygen by electrolysis - Google Patents

Description

June 23, 1925.

E. BAUR PROCESS FOR THE RECOVERY OF HYDROGEN AND OXYGEN BY ELECTROLYSIS Filed Sept. ,2, 1921 plate mw of iron Patented June 23, 1925.,

Emir. sum; or ZURICH, SWITZERLAND.

PROCESS FOR THE RECOVERY-OF HYDROGEN AND OXYGEN BY ELECTROLYSIS.

Application filed September 2, 1921. Serial No. 498,034.

To all whom it may concern:

Be it known that I, EMIL BAUR, residing at 53 Ottikerstrasse, Zurich 6, Switzerland, a citizen of Germany, have invented certain new and useful Improvements in Processes for the Recovery of Hydrogen and Oxygen by Electrolysis (for which I filed application in Germany May 29, 1920), of

which the following is a specification.

The usual methods of producing hydrogen and oxygen electrolytically are deficient for two reasons. Because .of the overvoltage, especially at the anode, there are polarizations of two volts and more even at low current-densities, and because of the resistance of the usual aqueous electrolytes, of the polarization by dilution and of increasing over-voltage it is not possible to overcome moderate current-densities in the range of size of one ampere per sq. din. By lowering the polarization to about the value of the reversible voltage of the hydrogenoxygen-cell and b increasing the currentdensity it would be possible to reduce the expenses for the current and for the cell.

It has now been found that the electrolysis of molten caustic soda or potash or mixtures of the same, when they contain water, goes on without sensible overvoltage, 'though the current-densities are taken very high. Asa fact, it is known, that on electrolysis of water-containing caustic soda hydrogen and oxygen are enerated (of. Leblanc and Brode, Zeitsc rift fiir Elektrochemie 1902, pag. 698), but in these experiences only little quantities of hydrogen and oxygen were evolved by an accessory reaction, hence it cannot be seen, that the gases are formed in acondition suitable for technical purposes. With'reference to .aqueous solutions it was to presume,that an overvoltage would arise with higher currentdensities. On the contrary it was found that no overvoltage appears even with very high current-densities. With a current-intensity of ten to twent amperes per sq. dm and with a distance 0 four to five cm. be tween the electrodes the voltage of the'cell ailixed my signature.

amounts to only 1,5 volts, so that both energy and space are much better availed than in all water-electrolyzers yet known.

The following process for the electrolysis of water is based on this knowledge:

The accompanying drawing illustrates onev form of, apparatus for-carrying out the method. I

In thesaidl drawing,

-Figure 1 is a: vertical section.

Figure .2 is a vertical .section at right angles thereto.

Like numerals indicate like parts in the different views.

A square vat 1 of iron-plate contains molten caustic soda or potash with a content of about five to ten per cent of water. The electrolyte is heated to about 250 up to 300. C. A set of small rectangular gasometers 2, made of iron-plate, plunge into the fused electrolyte. The gasometers contain insulated electrodes 4 of iron-plate 5, alternatively connected with the positive and negative pole. Out of every gasometer arises a'pi e 3 to lead away hydrogen and oxygen. with a stream. of water-vapour, which must be led to the kathodicchambers in the same rate, as the products of theelectrolysis escape out of the cell. To roduce the vapour, the heat, carried off by t e gaseous pro nets of the electrolysis can be used following to the well-known principles of heaft-regenerat- I ing. The whole electrolytical cell may be surrounded by a heat-insulating cover and a suitable heating-wire, to keep the cell on the needed temperature.

I claim:

A processor method for the recovery of pecial pipes provide the bathhydrogen and oxygen, which consists in electrolyzing with high current-densities molten caustic soda or potash or mixtures of the same, containing water in solution and restoring the water, decomposed. by electrolysis, substantially as described.

In testimony whereof I have hereunto Pxor'ussos mm. BAUR.

Images