Electrochemical method of ammonia generation

Patent metadata

Field	Value
Publication number	US-11560638-B2
Application number	US-201716320669-A
Country	US
Kind code	B2
Filing date	Jul 19, 2017
Priority date	Jul 28, 2016
Publication date	Jan 24, 2023
Grant date	Jan 24, 2023

Abstract

An electrolysis apparatus for producing ammonia, the apparatus comprising: a cathode; an anode; an electrolyte; a current source; a supply for nitrogen; and a supply for an acid, wherein the acid comprises at least one acid selected from the group consisting of: HCl, HBr, and HI.

First claim

What is claimed is:

1. An electrolysis apparatus for producing ammonia, the apparatus comprising:
a cell;
a cathode disposed in the cell;
an anode disposed in the cell;
an electrolyte within the cell, the electrolyte comprising dissolved metal ions;
a current source connected to the cathode and the anode;
a supply for providing nitrogen gas to the cell, the nitrogen converted into nitride ions at the cathode;
wherein the nitride ions and the dissolved metal ions form a nitride compound in the electrolyte; and
a supply for an acid to the cell, the acid purging the nitride compound from the electrolyte;
wherein the acid comprises at least one acid selected from the group consisting of: HCl, HBr, and HI, and
wherein the supply for the acid comprises at least one material selected from the group consisting of: stainless steel and nickel-based alloys;
wherein the anode comprises a metal selected from the group consisting of: Li, Mg, Ca, Sr, Ba, Zn, and Al.

2. The electrolysis apparatus according to claim 1 , wherein the anode comprises at least 10 wt. % of a metal selected from the group consisting of: Li, Mg, Ca, Sr, Ba, Zn, and Al, based on the total weight of the anode.

3. The electrolysis apparatus according to claim 1 , further comprising a heater.

4. The electrolysis apparatus according to claim 1 , further comprising a switch for reversing the polarity of the cathode and anode.

5. The electrolysis apparatus according to claim 1 , wherein the anode comprises a solid electrode or a coated conductive sheet.

6. The electrolysis apparatus according to claim 1 , wherein the anode comprises a porous structure.

7. The electrolysis apparatus according to claim 1 , wherein the electrolyte has a melting point below the decomposition temperature of ammonia.

8. A method of electrolytically producing ammonia, the method comprising:
forming nitride ions by converting nitrogen gat a cathode;
forming metal ions from a metal at an anode comprising the metal;
combining the nitride ions and the metal ions to form a nitride compound in an electrolyte during electrolysis; and
purging the nitride compound from the electrolyte with an acid, wherein the acid is selected from a group consisting of: HCl, HBr, and HI.

9. The method of claim 8 , wherein the metal is selected from the group consisting of: Li, Mg, Ca, Sr, Ba, Zn, and Al.

10. The method of claim 8 , further comprising heating the electrolyte to a temperature below 500° C.

11. The method of claim 8 , further comprising supplying nitrogen through the cathode.

12. The method of claim 8 , further comprising supplying the acid through the anode.

13. The method of any claim 8 , further comprising switching the polarity of the anode and cathode after production of ammonia.

14. The method of claim 13 , further comprising regenerating the anode after switching polarity of the anode and the cathode.

15. The method of claim 8 , further comprising supplying the energy for the electrolysis from renewable sources.

Assignees

• Siemens Ag

Inventors

• Schmid Günter
• Hughes Timothy
• Taroata Dan

Classifications

• C25B9/00

  Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features · CPC title

• C25B1/00

  Electrolytic production of inorganic compounds or non-metals · CPC title

• C25B15/08 Primary

  Supplying or removing reactants or electrolytes; Regeneration of electrolytes · CPC title

• C25B1/27

  Ammonia · CPC title

• C25B11/051

  Electrodes formed of electrocatalysts on a substrate or carrier · CPC title