Ammonia separation method and zeolite

Patent metadata

Field	Value
Publication number	US-10946333-B2
Application number	US-201916713360-A
Country	US
Kind code	B2
Filing date	Dec 13, 2019
Priority date	Jun 15, 2017
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

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 an aluminosilicate 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.

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 in a range of 50° C. to 500° C.

4. The method according to claim 1 , wherein the aluminosilicate 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 aluminosilicate zeolite membrane comprises a zeolite having a molar ratio of N element to Al element from 0.01 to 4, as determined by X-ray photoelectron spectroscopy.

7. The method according to claim 1 , wherein the aluminosilicate zeolite membrane comprises a zeolite having a molar ratio of Si element to Al element from 2.0 to 10, as determined by X-ray photoelectron spectroscopy.

8. The method according to claim 1 , wherein the aluminosilicate zeolite membrane comprises a zeolite having a molar ratio of alkali metal element to Al element from 0.01 to 0.070, as determined by X-ray photoelectron spectroscopy.

9. An aluminosilicate zeolite membrane comprising a zeolite, wherein the zeolite has a molar ratio of N element to Al element from 0.01 to 4, as determined by X-ray photoelectron spectroscopy.

10. An aluminosilicate zeolite membrane comprising a zeolite, wherein the zeolite has a molar ratio of Si element to Al element from 2.0 to 10, as determined by X-ray photoelectron spectroscopy.

11. An aluminosilicate zeolite membrane comprising a zeolite, wherein the zeolite has a molar ratio of alkali metal element to Al element from 0.01 to 0.070, as determined by X-ray photoelectron spectroscopy.

12. A method for separating ammonia from a gas mixture comprising ammonia gas, and hydrogen gas, nitrogen gas, or both, the method comprising:
contacting the gas mixture with a zeolite membrane composite thereby allowing the ammonia gas to permeate the zeolite membrane composite and separate from the gas mixture,
wherein the zeolite membrane composite comprises a porous support and an aluminosilicate zeolite membrane comprising a zeolite,
wherein:
the aluminosilicate zeolite membrane is deposited on a surface of the porous support; and
a change rate of a thermal expansion coefficient at 300° C. with respect to a thermal expansion coefficient at 30° C. of the zeolite is equal to or within ±0.25% and a change rate of a thermal expansion coefficient at 400° C. with respect to the thermal expansion coefficient at 30° C. of the zeolite is equal to or within ±0.35%.

13. The method according to claim 12 , wherein the change rate of the thermal expansion coefficient at 400° C. with respect to the thermal expansion coefficient at 30° C. of the zeolite with respect to the change rate of the thermal expansion coefficient at 300° C. with respect to the thermal expansion coefficient at 30° C. of the zeolite is equal to or within ±120%.

Assignees

• Mitsubishi Chem Corp

Inventors

• Tanaka Manabu
• Matsuo Takeshi
• Aoshima Takayuki

Classifications

• B01D69/108

  Inorganic support material · CPC title

• B01D71/0281

  Zeolites · CPC title

• B01D69/02

  characterised by their properties · CPC title

• C01C1/0458

  Separation of NH3 (during purge gas treatment C01C1/0476) · CPC title

• Y02P20/52

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