Integrated gasification and electrolysis process

Patent metadata

Field	Value
Publication number	US-11267767-B2
Application number	US-202117140831-A
Country	US
Kind code	B2
Filing date	Jan 4, 2021
Priority date	Jul 13, 2018
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

Aspects of the invention relate to improvements in the flexibility with which oxygen and hydrogen, for example from electrolysis, may be supplied to processes having both gasification and methanation steps, as well as improvements in how such processes may be operated in response to variations in carbonaceous feeds. Offsets, between the ideal quantity of hydrogen and the quantity available from a given source may be compensated for by adjusting one or more operations of the process, and in particular such operation(s) that ultimately impact the quantity of CO and/or CO2 available downstream of the gasifier for conversion to methane in an RNG product stream.

First claim

What is claimed is:

1. A process for gasification of a carbonaceous feed, the process comprising:
in a gasifier, contacting the carbonaceous feed with an oxygen-containing gasifier feed, performing a series of operations downstream of the gasifier to provide a gasifier effluent comprising CO, CO 2 and H 2 , wherein at least one of said series of operations causes a change in a concentration of CO and/or CO 2 from an inlet of said at least one operation to an outlet of said at least one operation, or otherwise causes a change in a relative amount of CO and/or CO 2 from the inlet of said at least one operation to the outlet of said at least one operation, and
adjusting said at least one of said series of operations, in response to a makeup quantity of hydrogen,
wherein said adjusting is performed to maintain a CO/H 2 and/or a CO 2 /H 2 molar ratio of the gasifier effluent, following combining of said makeup quantity of hydrogen with a product of any of said series of operations.

2. The process of claim 1 , wherein the makeup quantity of hydrogen comprises electrolysis hydrogen.

3. The process of claim 2 , wherein the electrolysis hydrogen is provided by an electrolyzer that further provides at least a portion of a makeup quantity of oxygen that is present in the oxygen-containing gasifier feed.

4. The process of claim 1 , wherein said at least one of said series of operations (i) consumes or produces CO or CO 2 in the process, or (ii) adds or removes CO or CO 2 in the process.

5. The process of claim 4 , wherein said at least one of said series of operations is a sour shift operation that consumes CO and produces CO 2 in the process, or an acid gas removal operation that removes CO and CO 2 in the process.

6. The process of claim 1 , wherein the operation is adjusted by bypassing at least a portion of a feed to the operation.

7. The process of claim 1 , wherein the carbonaceous feed comprises coal or biomass.

8. The process of claim 1 , wherein a makeup quantity of oxygen that is present in the oxygen-containing gasifier feed comprises electrolysis oxygen, obtained from an electrolyzer.

9. The process of claim 8 , wherein the makeup quantity of oxygen that is present in the oxygen-containing gasifier feed further comprises ASU oxygen obtained from an air separation unit.

10. The process of claim 1 , wherein a makeup quantity of oxygen that is present in the oxygen-containing gasifier feed is determined at least partly based on a makeup quantity of the carbonaceous feed and/or a characteristic of the carbonaceous feed.

11. The process of claim 10 , wherein said makeup quantity of oxygen is determined based on both the makeup quantity of the carbonaceous feed and the characteristic of the carbonaceous feed.

12. The process of claim 11 , wherein the characteristic is a carbon content of the carbonaceous feed.

13. The process of claim 1 , wherein the oxygen-containing gasifier feed further comprises H 2 O and/or CO 2 .

14. The process of claim 1 , wherein the series of operations includes one or more of a tar conversion operation, a gasifier heat recovery operation, a gas filtration/scrubbing operation, a sulfur removal operation, and a supplemental cleaning operation.

15. The process of claim 1 , further comprising reacting at least a portion of the makeup quantity of hydrogen with at least a portion of the CO and/or CO 2 in the gasifier effluent.

16. The process of claim 15 , wherein the step of reacting is in a methanation reactor to form methane.

17. An integrated gasification and electrolysis process, the process comprising:
in a gasifier of a gasification zone, contacting biomass with an oxygen-containing gasifier feed to provide a gasification zone effluent comprising CO, CO 2 and H 2 ,
wherein the oxygen-containing gasifier feed comprises electrolysis oxygen obtained from electrolysis of water in an electrolyzer, and
wherein the gasification zone comprises at least one operation, downstream of the gasifier, affecting CO concentration or CO 2 concentration of the gasification zone effluent,
the process further comprising adjusting the at least one operation in response to a makeup quantity of electrolysis hydrogen obtained from the electrolyzer.

18. The process of claim 17 , wherein the at least one operation is a sour shift operation that consumes CO and produces CO 2 in the process, or an acid gas removal operation that removes CO and CO 2 in the process.

19. The process of claim 17 , wherein the at least one operation is adjusted by bypassing at least a portion of a feed to the operation.

20. The process of claim 17 , wherein, in addition to the at least one operation affecting CO concentration or CO 2 concentration, the gasification zone further comprises one or more of a tar conversion operation, a gasifier heat recovery operation, a gas filtration/scrubbing operation, a sulfur removal operation, and a supplemental cleaning operation.

Assignees

• Gas Technology Inst

Inventors

• Kramer Andrew
• Seaba James
• Lamont David C

Classifications

• C10J2300/093

  Coal · CPC title

• C10L3/08

  Production of synthetic natural gas · CPC title

• C10J2300/0916

  Biomass · CPC title

• C10L2200/0469

  Renewables or materials of biological origin · CPC title

• C10J3/723 Primary

  Controlling or regulating the gasification process · CPC title