Treatment of acid gases using molten alkali metal borates and associated methods of separation

Patent metadata

Field	Value
Publication number	US-11291950-B2
Application number	US-202017090180-A
Country	US
Kind code	B2
Filing date	Nov 5, 2020
Priority date	Nov 7, 2019
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

The removal of acid gases (e.g., non-carbon dioxide acid gases) using sorbents that include salts in molten form, and related systems and methods, are generally described.

First claim

What is claimed is:

1. A method, comprising:
exposing a sorbent, the sorbent comprising a salt in molten form, to an environment containing a non-CO 2 acid gas such that at least a portion of the non-CO 2 acid gas interacts with the sorbent and at least a portion of the non-CO 2 acid gas is removed from the environment,
wherein captured non-CO 2 acid gas is released in the gas phase in a separate environment and upconcentrated.

2. The method of claim 1 , wherein the non-CO 2 acid gas comprises sulfur monoxide (SO), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), hydrogen sulfide (H 2 S), sulfur trioxide (SO 3 ), nitric oxide (NO), nitrous oxide (N 2 O), dinitrogen trioxide (N 2 O 3 ), dinitrogen tetroxide (N 2 O 4 ), dinitrogen pentoxide (N 2 O 5 ), and/or carbonyl sulfide (COS).

3. The method of claim 1 , wherein the environment is at a temperature of at least 200° C.

4. The method of claim 1 , wherein a plurality of non-CO 2 acid gases interacts with the sorbent such that at least a portion of the plurality of non-CO 2 acid gases are removed from the environment.

5. The method of claim 1 , wherein the release is driven, at least in part, by a change in partial pressure of the non-CO 2 acid gas and/or a change in temperature in the second environment relative to the first environment.

6. A method, comprising:
exposing a sorbent, the sorbent comprising a salt in molten form, to an environment containing a non-CO 2 acid gas such that at least a portion of the non-CO 2 acid gas interacts with the sorbent and at least a portion of the non-CO 2 acid gas is removed from the environment,
wherein captured non-CO 2 acid gas forms a solid suspended in the sorbent and is upconcentrated by physical separation.

7. The method of claim 6 , where the physical separation uses a cross-flow filter, centrifugation, crystallization, and/or sedimentation.

8. The method of claim 6 , wherein the physical separation uses a cross-flow filter, and the cross-flow filter is operated at a temperature of at least 200° C.

9. The method of claim 6 , wherein the non-CO 2 acid gas comprises sulfur monoxide (SO), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), hydrogen sulfide (H 2 S), sulfur trioxide (SO 3 ), nitric oxide (NO), nitrous oxide (N 2 O), dinitrogen trioxide (N 2 O 3 ), dinitrogen tetroxide (N 2 O 4 ), dinitrogen pentoxide (N 2 O 5 ), and/or carbonyl sulfide (COS).

10. The method of claim 6 , wherein the environment is at a temperature of at least 200° C.

11. A method, comprising:
exposing a sorbent, the sorbent comprising a salt in molten form, to an environment containing a non-CO 2 acid gas such that at least a portion of the non-CO 2 acid gas interacts with the sorbent and at least a portion of the non-CO 2 acid gas is removed from the environment,
wherein at least a portion of the sorbent containing at least the portion of the non-CO 2 acid gas is removed from the environment.

12. The method of claim 11 , wherein the non-CO 2 acid gas comprises sulfur monoxide (SO), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), hydrogen sulfide (H 2 S), sulfur trioxide (SO 3 ), nitric oxide (NO), nitrous oxide (N 2 O), dinitrogen trioxide (N 2 O 3 ), dinitrogen tetroxide (N 2 O 4 ), dinitrogen pentoxide (N 2 O 5 ), and/or carbonyl sulfide (COS).

13. The method of claim 11 , wherein the environment is at a temperature of at least 200° C.

14. A method, comprising:
exposing a sorbent, the sorbent comprising a salt in molten form, to an environment containing a non-CO 2 acid gas such that at least a portion of the non-CO 2 acid gas interacts with the sorbent and at least a portion of the non-CO 2 acid gas is removed from the environment,
further comprising adding a solution to the environment to precipitate at least a portion of the sorbent.

15. The method of claim 14 , wherein the solution contains calcium ions.

16. The method of claim 14 , wherein adding the solution results in the precipitation of CaSO 4 .

17. The method of claim 14 , wherein the non-CO 2 acid gas comprises sulfur monoxide (SO), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), hydrogen sulfide (H 2 S), sulfur trioxide (SO 3 ), nitric oxide (NO), nitrous oxide (N 2 O), dinitrogen trioxide (N 2 O 3 ), dinitrogen tetroxide (N 2 O 4 ), dinitrogen pentoxide (N 2 O 5 ), and/or carbonyl sulfide (COS).

18. The method of claim 14 , wherein the environment is at a temperature of at least 200° C.

Assignees

• Massachusetts Inst Technology

Inventors

• Hatton Trevor Alan
• Harada Takuya
• Halliday Cameron G

Classifications

• B01D53/1425

  Regeneration of liquid absorbents · CPC title

• B01D2257/404

  Nitrogen oxides other than dinitrogen oxide · CPC title

• B01D2257/304

  Hydrogen sulfide · CPC title

• C01B35/128 Primary

  containing plural metal or metal and ammonium · CPC title

• B01D53/56

  Nitrogen oxides (B01D53/60 takes precedence) · CPC title