Electrolysis process and apparatus

• US 5,843,297 A
• Filed: 09/23/1996
• Issued: 12/01/1998
• Est. Priority Date: 09/22/1995
• Status: Expired due to Fees

• Current Assignee: Dornier GmbH (Government of France)
• Original Assignee: Dornier GmbH (Government of France)
• Inventors: Kurzweil, Peter, Schmid, Ottmar
• Primary Examiner(s): Gorgos, Kathryn L.
• Assistant Examiner(s): Wong, Edna
• Application Number:
  US08/723,883
• Time in Patent Office: 799 Days
• Field of Search: 204/286, 204/256, 204/258, 204/266, 204/296, 204/237, 204/252, 205/742, 205/746, 205/748, 205/343, 205/344, 205/349
• US Class Current: 205/687
• CPC Class Codes: C25B 1/04 by electrolysis of water
• CPC Class Codes: C25B 15/08 Supplying or removing reactants or electrolytes; Regeneration of electrolytes
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

A method and apparatus for carrying out an electrolytic process produces clean gases, such as oxygen and hydrogen. For this purpose, a porous diaphragm is arranged between the cathode and the anode of an electrolyzer, and a liquid electrolyte is fixed in the pores of the cathode and anode. A first gas chamber adjoins the cathode, while a second gas chamber adjoins the anode, and an educt chamber is separated from the first gas chamber by a membrane. An aqueous, non-corrosive solution of salts of inorganic and organic acids or mixtures of water with organic additives is used as an educt, which, compared with the electrolyte, has a higher partial water vapor pressure.

Claims

1. An electrolysis process for use in an electrolyzer having

porous electrodes, including at least a cathode and an anode;

a porous diaphragm arranged between said porous electrodes;

a liquid electrolyte fixed in pores of the electrodes and of the diaphragm;

a first product gas chamber adjoining the cathode;

a second product gas chamber adjoining the anode; and

an educt chamber separated from the first product gas chamber by a membrane;

said process comprising;

using an aqueous, non-corrosive solution as an educt which, compared with the electrolyte, has a higher partial water vapor pressure; and

supplying electrolysis water from the educt to the electrolyte which is fixed in the pores of the electrodes, by gas diffusion from the educt chamber via the membrane and the first product gas chamber;

wherein said aqueous solution is an aqueous solution of salts of inorganic and organic acids or mixtures of water with organic additives.

2. Process according to claim 1, wherein the aqueous solution contains sodium acetate.

3. Process according to claim 1, wherein the electrolyte is a concentrated, aqueous solution having a high electric conductivity.

4. Process according to claim 1, wherein said aqueous solution comprises at least one material selected from the group consisting of phosphates and acetates.

5. Process according to claim 1, wherein said organic additives comprise at least one material selected from the group consisting of glycols, urea and glycerine.

7. Electrolyzer according to claim 5, wherein the membrane consists of a single nonporous layer.

8. Electrolyzer according to claim 7, wherein an educt which is used in said electrolyzer is pressurized directly by a product gas pressure.

6. An electrolyzer comprising:

porous electrodes, including at least a cathode and an anode;

a porous diaphragm arranged between said porous electrodes;

a liquid electrolyte fixed in pores of the electrodes and the diaphragm;

a first product gas chamber adjoining the cathode;

a second product gas chamber adjoining the anode; and

an educt chamber separated from the first product gas chamber by a membrane having at least one nonporous layer.

9. Electrolyzer according to claim 6 wherein the membrane has a porous hydrophilic layer disposed toward the educt chamber and has a porous hydrophobic layer disposed toward the first product gas chamber.

10. Electrolyzer according to claim 6 wherein the membrane has a porous hydrophilic layer disposed toward the educt chamber and has a dense layer disposed toward the first product gas chamber.

11. Electrolyzer according to claim 6, wherein the membrane has a nonporous layer disposed toward the educt chamber and has a porous hydrophobic layer disposed toward the first product chamber.

12. Electrolyzer according to claim 6, wherein the electrolyte is a concentrated, aqueous solution having a high electric conductivity.

13. Electrolyzer arrangement, comprising a plurality of series-connected electrolyzers according to claim 6.