Configurations and methods for processing high pressure acid gases with zero emissions

Patent metadata

Field	Value
Publication number	US-9902914-B2
Application number	US-201514924311-A
Country	US
Kind code	B2
Filing date	Oct 27, 2015
Priority date	Oct 27, 2015
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

Plants, processes, and methods for reducing the H 2 S and CO 2 contents of shale gasses from fields that produce shale gasses having varying H 2 S and CO 2 contents are provided. Acid gas enters an absorber and is scrubbed using a lean physical solvent, producing a treated gas and a rich physical solvent. The H 2 S content of the treated gas is further reduced in an amine absorber, producing a pipeline gas and a semi-lean amine. The pipeline gas contains lower levels of H 2 S and CO 2 than gas produced using a polishing bed. A physical solvent regeneration unit regenerates the lean physical solvent from the rich physical solvent for feeding into the absorption unit. An amine regeneration unit regenerates the lean amine from the semi-lean amine for feeding into the amine absorber. Contemplated plants may further comprise a Claus Unit or a Redox unit for oxidizing H 2 S to elemental sulfur.

First claim

What is claimed is:

1. An acid gas processing plant, comprising:
an absorption unit configured to (i) receive a feed gas comprising H2S and CO2 and (ii) use a lean physical solvent to absorb a portion of H2S and CO2 within the feed gas to produce a treated gas and a rich physical solvent;
an amine absorber coupled to the absorption unit and configured to (i) receive the treated gas from the absorption unit and (ii) use a first portion of a lean amine to absorb a portion of H2S and CO2 within the treated gas to produce a pipeline gas and a semi-lean amine;
a physical solvent regeneration unit coupled to the absorption unit and configured to (i) receive the rich physical solvent from the absorption unit and (ii) regenerate the lean physical solvent from the rich physical solvent for feeding into the absorption unit,
wherein the physical solvent regeneration comprises a first separator that is configured to produce a first flashed gas as a byproduct of regenerating a first semi-lean physical solvent from the rich physical solvent; and
an amine regeneration unit coupled to the amine absorber and configured to (i) receive the semi-lean amine from the amine absorber and (ii) regenerate the lean amine from the semi-lean amine for feeding into the amine absorber,
wherein the amine regeneration unit comprises a fuel gas scrubber that is configured to (i) receive the first flashed gas and (ii) use a second portion of the lean amine to scrub the first flashed gas to produce a fuel gas and a rich amine.

2. The plant of claim 1 , wherein the physical solvent regeneration unit further comprises a second separator that is configured to produce a second flashed gas as a byproduct of regenerating a second semi-lean physical solvent from the first semi-lean physical solvent.

3. The plant of claim 1 , wherein the amine regeneration unit comprises a regenerator that is configured to (i) receive the rich amine from the fuel gas scrubber and (ii) produce an H 2 S rich stream as a byproduct of regenerating the lean amine from the rich amine.

4. The plant of claim 3 , further comprising a redox unit that is configured to (i) receive a portion of the H 2 S rich stream from the regenerator and the second flashed gas from the second separator and (ii) apply an iron-chelate to the H 2 S rich stream and the second flashed gas to produce elemental sulfur and a CO 2 rich stream.

5. The plant of claim 2 , wherein the amine regeneration unit comprises a second amine absorber that is configured to (i) receive the second flashed gas from the second separator and (ii) use a third portion of the lean amine to produce a CO 2 rich stream and a rich amine.

6. The plant of claim 5 , wherein the amine regeneration unit comprises a regenerator that is configured to (i) receive the rich amine from second amine absorber and (ii) produce an H 2 S rich stream as a byproduct of regenerating the lean amine from the rich amine.

7. The plant of claim 6 , further comprising a Claus unit configured to receive a portion of the H 2 S rich stream from the regenerator to produce elemental sulfur.

8. The plant of claim 1 , wherein the lean physical solvent comprises at least one of FLUOR SOLVENT™ (propylene carbonate), NMP (normal-methyl pyrolidone), SELEXOL™ (dimethyl ether of polyethylene glycol), TBP (tributyl phosphate), and polyethylene glycol dialkyl ethers.

9. The plant of claim 1 , wherein the lean amine comprises at least one of MDEA, DIPA, hindered amine, or other formulated tertiary amines.

10. An acid gas removal plant, comprising:
a physical solvent absorption unit configured to receive a feed gas comprising H2S and CO2 and a lean physical solvent to produce a treated gas and a rich physical solvent;
an amine absorption unit configured to receive the treated gas and a lean amine stream and to produce a pipeline gas;
multi-stage flash regeneration separators configured to receive a rich physical solvent from the physical solvent absorption unit and to produce the lean physical solvent,
wherein the multi-stage flash regeneration separators comprise a first separator that is configured to produce a first flashed gas as a byproduct of regenerating a first semi-lean physical solvent from the rich physical solvent; and
an amine unit configured to receive a semi-rich amine stream from the amine absorption unit to remove the H2S and CO2 from a flashed gas from the multi-stage flash regeneration separators to produce a fuel gas and a rich amine stream,
wherein the amine unit comprises a fuel gas scrubber that is configured to (i) receive the first flashed gas and (ii) use a second portion of the lean amine to scrub the first flashed gas to produce a fuel gas and a rich amine.

11. An acid gas processing plant, comprising:
an absorption unit configured to (i) receive a feed gas comprising H2S and CO2 and (ii) use a lean physical solvent to absorb a portion of H2S and CO2 within the feed gas to produce a treated gas and a rich physical solvent;
an amine absorber coupled to the absorption unit and configured to (i) receive the treated gas from the absorption unit and (ii) use a first portion of a lean amine to absorb a portion of H2S and CO2 within the treated gas to produce a pipeline gas and a semi-lean amine;
a physical solvent regeneration unit coupled to the absorption unit and configured to (i) receive the rich physical solvent from the absorption unit and (ii) regenerate the lean physical solvent from the rich physical solvent for feeding into the absorption unit,
wherein the physical solvent regeneration unit comprises (i) a first separator that is configured to produce a first flashed gas as a byproduct of regenerating a first semi-lean physical solvent from the rich physical solvent, and (ii) a second separator that is configured to produce a second flashed gas as a byproduct of regenerating a second semi-lean physical solvent from the first semi-lean physical solvent; and
an amine regeneration unit coupled to the amine absorber and configured to (i) receive the semi-lean amine from the amine absorber and (ii) regenerate the lean amine from the semi-lean amine for feeding into the amine absorber,
wherein the amine regeneration unit comprises a second amine absorber that is configured to (i) receive the second flashed gas from the second separator and (ii) use a third portion of the lean amine to produce a CO 2 rich stream and a rich amine.

12. The plant of claim 11 , wherein the amine regeneration unit comprises a fuel gas scrubber that is configured to (i) receive the first flashed gas and (ii) use a second portion of the lean amine to scrub the first flashed gas to produce a fuel gas and a rich amine.

13. The plant of claim 12 , wherein the amine regeneration unit comprises a regenerator that is configured to (i) receive the rich amine from the fuel gas scrubber and (ii) produce an H 2 S rich stream as a byproduct of regenerating the lean amine from the rich amine.

14. The plant of claim 13 , further comprising a redox unit that is configured to (i) receive a portion of the H 2 S rich stream from the regenerator and the second flashed gas from the second separator and (ii) apply an iron-chelate to the H 2 S rich stream and the second flashed gas to produce elemental sulfur and a CO 2 rich stream.

15. The plant of claim 11 , wherein the amine regeneration unit comprises a regenerator that is configured to (i) receive the rich amine from second amine absorber and (ii) produce an H 2 S rich stream as a byproduct of regenerating the lean amine from the rich amine.

16. The plant of claim 15 , further comprising a Claus unit configured

Assignees

• Fluor Tech Corp

Inventors

• Mak John

Classifications

• C10L3/102

  of acid contaminants · CPC title

• C10L2290/12

  Regeneration of a solvent, catalyst, adsorbent or any other component used to treat or prepare a fuel · CPC title

• C10L2290/541

  Absorption of impurities during preparation or upgrading of a fuel · CPC title

• C01B17/0408

  Pretreatment of the hydrogen sulfide containing gases · CPC title

• C10L3/104 Primary

  Carbon dioxide · CPC title