Ammonia separation method and zeolite

Patent metadata

Field	Value
Publication number	US-11833468-B2
Application number	US-202217830375-A
Country	US
Kind code	B2
Filing date	Jun 2, 2022
Priority date	Jun 15, 2017
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

Provided is a method for separating ammonia gas using zeolite membrane having excellent separation stability at a high temperature capable of separating ammonia gas from a mixed gas composed of multiple components including ammonia gas, hydrogen gas, and nitrogen gas to the permeation side with high selectivity and high permeability. Also provided is a method for separating ammonia by selectively permeating ammonia gas from a mixed gas containing at least ammonia gas, hydrogen gas, and nitrogen gas using a zeolite membrane, wherein the ammonia gas concentration in the mixed gas is 1.0% by volume or more.

First claim

The invention claimed is:

1. A method for separating ammonia from a mixed gas comprising ammonia gas, hydrogen gas, and nitrogen gas, the method comprising:
contacting the mixed gas with a zeolite membrane thereby allowing the ammonia gas to selectively permeate the zeolite membrane and separate from the mixed gas,
wherein a concentration of the ammonia gas in the mixed gas is 1.0% by volume or more relative to a total volume of the mixed gas, and
the zeolite membrane has an SiO 2 /Al 2 O 3 molar ratio of from 6 to 500.

2. The method according to claim 1 , wherein a volume ratio of hydrogen gas/nitrogen gas in the mixed gas is from 0.2 to 3.

3. The method according to claim 1 , wherein the temperature at which the ammonia gas is separated from the mixed gas is from 50° C. to 500° C.

4. The method according to claim 1 , wherein the zeolite membrane comprises RHO zeolite or MFI zeolite.

5. The method according to claim 1 , wherein at least a portion of the ammonia gas in the mixed gas is produced from hydrogen gas and nitrogen gas in the mixed gas.

6. The method according to claim 1 , wherein the concentration of the ammonia gas in the mixed gas is from 2.0% by volume to 60% by volume relative to the total volume of the mixed gas.

7. The method according to claim 1 , wherein the pressure of the mixed gas is from 0.1 MPa to 20 MPa.

8. The method according to claim 1 , wherein a differential pressure between the mixed gas and the gas that has permeated the zeolite membrane is from 0.01 MPa to 10 MPa.

9. The method according to claim 1 , wherein the zeolite membrane is formed by crystallizing zeolite on a surface of a porous support.

10. The method according to claim 1 , wherein the zeolite membrane is formed on a tubular support.

11. The method according to claim 10 , wherein the mixed gas is supplied to the outside of the tubular support on which the zeolite membrane is formed.

Assignees

• Mitsubishi Chem Corp

Inventors

• Tanaka Manabu
• Matsuo Takeshi
• Aoshima Takayuki

Classifications

• B01D69/108

  Inorganic support material · CPC title

• B01D71/0281

  Zeolites · CPC title

• B01D53/228 Primary

  characterised by specific membranes · CPC title

• B01D69/02

  characterised by their properties · CPC title

• B01D69/10

  Supported membranes; Membrane supports · CPC title