Ammonia synthesis using a catalytic nitrogen-selective membrane

Patent metadata

Field	Value
Publication number	US-10556803-B2
Application number	US-201715707007-A
Country	US
Kind code	B2
Filing date	Sep 18, 2017
Priority date	Sep 16, 2016
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

The invention relates to a metallic membrane for nitrogen separation, the method of making the membrane and methods of using the membrane. The invention also relates to a metallic membrane for disassociation of nitrogen and subsequent reaction with hydrogen to produce ammonia at moderate conditions compared to a conventional Haber-Bosch process.

First claim

What is claimed is:

1. A method of producing a nitrogen-hydrogen compound, comprising:
providing a metallic membrane, wherein the metallic membrane is an alloy comprising a Group V element;
providing a nitrogen (N 2 ) stream to a first side of the metallic membrane;
dissociating the N 2 into atomic nitrogen (N) with the metallic membrane;
reacting the dissociated nitrogen with a hydrogen gas on a second side of the metallic membrane;
forming at least one nitrogen-hydrogen compound, wherein the nitrogen-hydrogen compound is selected from the group consisting of NH, NH 2 , NH 3 , and combinations thereof;
desorbing the nitrogen-hydrogen compound from the metallic membrane; and
reacting the nitrogen-hydrogen compound with hydrogen to form an ammonium cation at a temperature between about 200° C. and about 1000° C.

2. The method of claim 1 , wherein the nitrogen stream is produced in a coal fired power plant.

3. The method of claim 1 , wherein the metallic membrane does not dissociate or adsorb at least one of a sulfur dioxide, a nitrogen dioxide, a nitrogen oxide, a carbon dioxide, or a hydrocarbon compound.

4. The method of claim 3 , wherein the hydrocarbon compound is methane.

5. The method of claim 1 , wherein the metallic membrane selectively dissociates nitrogen.

6. The method of claim 1 , wherein a source of the nitrogen is a flue gas.

7. The method of claim 1 , further comprising providing a purging gas to the metallic membrane, wherein the purging gas is selected from the group consisting of a hydrogen gas, a nitrogen gas, an argon gas, a sulfur dioxide, a nitrogen oxide, a nitrogen dioxide, and combinations thereof.

8. The method of claim 7 , wherein the purging gas is provided to the metallic membrane between about 1 and about 4 hours.

9. The method of claim 1 , wherein an operating temperature is less than 400° C.

10. The method of claim 1 , wherein the Group V element is selected from the group consisting of V, Ta, and Nb.

11. The method of claim 1 , wherein the alloy further comprises an alloying element selected from the group consisting of molybdenum, iron, and ruthenium.

12. The method of claim 1 , wherein the nitrogen stream is from a natural gas power plant.

13. The method of claim 1 , wherein the temperature is between about 400° C. and about 600° C.

14. The method of claim 1 , further comprising ramping a temperature of the metallic membrane from an initial temperature to an operating temperature of between 200° C. and about 1000° C., at a ramp rate of between about 1° C./minute and about 5° C./minute.

15. The method of claim 1 , wherein an operating pressure of the system is between about 14 psi and about 840 psi.

16. The method of claim 1 , further comprising diffusing the atomic nitrogen through interstitial crystal sites of a bulk metal of the metallic membrane.

17. The method of claim 1 , wherein the hydrogen is a sweeping gas comprising a hydrogen gas.

Assignees

• Colorado School Of Mines

Inventors

• Wilcox Jennifer
• Liguori Simona

Classifications

• B01D2256/10

  Nitrogen · CPC title

• Y02P20/52

  using catalysts, e.g. selective catalysts · CPC title

• B01D53/228

  characterised by specific membranes · CPC title

• C01C1/0411 Primary

  characterised by the catalyst · CPC title

• B01D71/025

  Aluminium oxide · CPC title