Systems and methods for ammonia recovery, acid gas separation, or combination thereof

• US 10,427,948 B2
• Filed: 01/25/2019
• Issued: 10/01/2019
• Est. Priority Date: 01/26/2018
• Status: Active Grant

• Current Assignee: Innovator Energy LLC
• Original Assignee: Ethan J. Novek
• Inventors: Novek, Ethan J.
• Primary Examiner(s): Holecek, Cabrena
• Application Number:
  US16/258,311
• Publication Number:
  US 20190233296A1
• Time in Patent Office: 249 Days
• CPC Class Codes: B01D 2251/2067 Urea
• CPC Class Codes: B01D 2252/102 Ammonia
• CPC Class Codes: B01D 2257/406 Ammonia
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2315/22 Membrane contactor
• CPC Class Codes: B01D 2317/022 Reject series
• CPC Class Codes: B01D 2317/06 Use of membrane modules of the same kind
• CPC Class Codes: B01D 2317/08 Use of membrane modules of different kinds
• CPC Class Codes: B01D 53/1418 Recovery of products
• CPC Class Codes: B01D 53/1462 Removing mixtures of hydrogen sulfide and carbon dioxide
• CPC Class Codes: B01D 53/1468 Removing hydrogen sulfide
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: B01D 53/229 Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption)
• CPC Class Codes: B01D 61/002 Forward osmosis or direct osmosis
• CPC Class Codes: B01D 61/0021 comprising multiple forward osmosis steps
• CPC Class Codes: B01D 61/025 Reverse osmosis; Hyperfiltration
• CPC Class Codes: B01D 61/026 comprising multiple reverse osmosis steps
• CPC Class Codes: B01D 61/027 Nanofiltration
• CPC Class Codes: B01D 61/029 Multistep processes comprising different kinds of membrane processes selected from reverse osmosis, hyperfiltration or nanofiltration
• CPC Class Codes: B01D 61/58 : Multistep processes
• CPC Class Codes: C01C 1/12 : Separation of ammonia from gases and vapours as part of the ammonia synthesis process C01C1/04
• CPC Class Codes: C01C 1/26 : Carbonates or bicarbonates of ammonium
• CPC Class Codes: C01C 1/28 : Methods of preparing ammonium salts in general
• CPC Class Codes: Y02C 20/40 : of CO2
• CPC Class Codes: Y02E 20/32 : Direct CO2 mitigation
• CPC Class Codes: Y02P 20/151 : Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

The present invention relates to processes and systems for ammonia recovery and/or acid-gas separation. In some embodiments, a system for acid gas separation may be integrated with an ammonia abatement cycle employing a high temperature absorber. In some embodiments, a system for acid gas separation may employ a higher temperature absorber due to the lower energy consumption and cost of the integrated ammonia abatement cycle. Advantageously, heat may be recovered from the absorber to power at least a portion of any acid gas desorption in the process. Reverse osmosis or other membranes may be employed.

Claims

1. A process for separating or recovering basic gases comprising:

(a) absorbing ammonia from an ammonia containing gas stream into an ammonia-lean, an ammonia-ultra-lean, or ammonia-free solution, to form an ammonia-rich solution;

(b) enriching said ammonia-rich solution with one or more acid gases to form an ammonia rich, acid gas rich solution; and

(c) concentrating said ammonia rich, acid gas rich solution using one or more membranes to form a retentate and a permeate wherein said permeate is suitable for use as at least a portion of the ammonia-ultra-lean or ammonia-free solution in step (a);

wherein one or more solutions comprise urea.

2. The process of claim 1 further comprising transferring said retentate to one or more further treatment steps.

3. The process of claim 1 wherein said ammonia containing gas stream comprises one or more other basic gases.

4. The process of claim 1 wherein the ammonia containing gas stream further comprises an acid gas.

5. The process of claim 1 further comprising absorbing an acid gas with the ammonia to form an acid gas rich, ammonia-rich solution.

6. The process of claim 5 wherein an acid gas is desorbed from said acid gas rich, ammonia-rich solution to form an acid gas lean, ammonia-rich solution and desorbed acid gas.

7. An integrated process for separating or recovering basic gases comprising:

(1) a first cycle comprising;

absorbing ammonia from an ammonia containing gas stream into an ammonia-lean solution, forming an ammonia-rich solution;

enriching said ammonia rich solution with one or more acid gases;

precipitating one or more ammonia-acid gas salts wherein said precipitating occurs during enriching, after enriching, or a combination thereof; and

separating at least a portion of said precipitate from any remaining liquid; and

(2) a second cycle comprising;

(a) absorbing ammonia from an ammonia containing gas stream into an ammonia-lean, an ammonia-ultra-lean, or ammonia-free solution, to form an ammonia-rich solution;

(b) enriching said ammonia-rich solution with one or more acid gases to form an ammonia-rich, acid gas rich solution; and

(c) concentrating said ammonia-rich, acid gas rich solution using one or more membranes to form a retentate and a permeate wherein said permeate is suitable for use as at least a portion of the ammonia-ultra-lean or ammonia-free solution in step (a) of the second cycle.

8. The process of claim 7 wherein the volume of permeate is greater than the volume of retentate.

9. The process of claim 7 wherein the volume ratio of permeate to retentate is greater than about 3:

1.

10. The process of claim 7 which further comprises combining at least a portion of the remaining liquid in the first cycle with at least a portion of the retentate in the second cycle and concentrating the combination using one or more membranes to form a second retentate and a second permeate.

11. The process of claim 10 wherein the volume of the second permeate is less than the volume of the second retentate.

12. The process of claim 10 wherein the volume ratio of second retentate to second permeate is greater than about 2:

1.

13. The process of claim 10 wherein said second retentate is suitable for use as the ammonia-lean solution in the first cycle.

14. The process of claim 10 wherein said second permeate is suitable for use as the ammonia-ultra-lean or ammonia-free solution in the second cycle.

15. The process of claim 10 which further comprises recycling at least a portion of said second permeate to be employed as at least a portion of the ammonia-ultra-lean or ammonia-free solution in the second cycle.

16. The process of claim 10 which further comprises recycling at least a portion of said second retentate to be employed as at least a portion of the ammonia-lean solution in the first cycle.

17. The process of claim 16 which further comprises mixing said second retentate with at least a portion of said ammonia-rich solution in the first cycle prior to or while employing said second retentate as said ammonia-lean solution in the first cycle.