System and method for power production including methanation

Patent metadata

Field	Value
Publication number	US-10634048-B2
Application number	US-201715434218-A
Country	US
Kind code	B2
Filing date	Feb 16, 2017
Priority date	Feb 18, 2016
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

The present disclosure relates to a power production system that is adapted to achieve high efficiency power production with carbon capture when using a solid or liquid hydrocarbon or carbonaceous fuel. More particularly, the solid or liquid fuel first is partially oxidized in a partial oxidation reactor that is configured to provide an output stream that is enriched in methane content. The resulting partially oxidized stream can be cooled, filtered, additionally cooled, and then directed to a combustor of a power production system as the combustion fuel. The partially oxidized stream is combined with a compressed recycle CO2 stream and oxygen. The combustion stream is expanded across a turbine to produce power and passed through a recuperator heat exchanger. The recycle CO2 stream is compressed and passed through the recuperator heat exchanger and optionally the POX heat exchanger in a manner useful to provide increased efficiency to the combined systems.

First claim

The invention claimed is:

1. A process for the production of power using a combination of a partial oxidation (PDX) system and a power production system (PPS), the process comprising:
combining a solid or liquid fuel, oxygen, and a catalyst in a PDX reactor under conditions sufficient to partially oxidize the fuel and form a PDX product stream comprising methane;
cooling the PDX product stream to a temperature of about 500° C. or less;
separating one or more of solids, molten metals, and acid gases from the cooled PDX product stream to produce a cooled and filtered PDX product stream;
passing the cooled and filtered PDX product stream through a splitter to split the cooled and filtered PDX product stream in a first fraction stream and a second fraction stream, the first fraction stream being passed through a catalytic water gas shift reactor configured to convert CO and H 2 O in the cooled and filtered PDX product stream to CO 2 and H 2 , and the second fraction stream being passed through a carbonyl sulfide (COS) hydrolysis reactor configured to convert COS to H 2 S, wherein the first fraction stream exiting the catalytic water gas shift reactor and the second product stream exiting the COS hydrolysis reactor combine to form a PDX fuel stream;
passing the PDX fuel stream to a PDX heat exchanger and withdrawing a quantity of heat from the PDX fuel stream by cooling the PDX fuel stream to a temperature of about 100° C. or less against a cooling stream and form a PDX fuel gas stream comprising methane;
passing the PDX fuel gas stream through a separator vessel and separating at least a portion of any water present in the PDX fuel gas stream;
compressing the filtered PDX fuel gas stream to a pressure of about 12 MPa or greater;
combusting the filtered and compressed PDX fuel gas in a PPS combustor to form a combustion product stream at a pressure of at least about 10 MPa and a temperature of at least about 800° C.; and
expanding the combustion product stream across a PPS turbine to generate power and form an expanded PPS combustion product stream;
wherein the filtered PDX fuel gas stream that is compressed to a pressure of about 12 MPa or greater has a methane content of about 20% or greater by volume based on the total volume of the filtered PDX fuel gas stream.

2. The process of claim 1 , wherein the catalyst used in the PDX reactor is selected from the group consisting of alkali metals, alkaline earth metals, transition metals, compounds thereof, complexes thereof, and combinations thereof.

3. The process of claim 1 , wherein the PDX reactor is operated at a temperature of about 1000° C. or less.

4. The process of claim 1 , further comprising adding steam to the PDX reactor.

5. The process of claim 1 , wherein cooling the PDX product stream from the PDX reactor comprises passing the PDX product stream through a convective cooler against a cooling stream.

6. The process of claim 5 , wherein the cooling stream comprises one or more of:
a high pressure recycle fluid stream withdrawn from and returned to the PPS;
a high pressure water stream;
a nitrogen stream;
a stream of PDX reactor liquid fuel feed;
a high pressure stream of O 2 and CO 2 ; and
a stream of cleaned and cooled PDX fuel gas.

7. The process of claim 1 , wherein the solids separated from the cooled PDX product stream comprise one or more of ash particles, unreacted char, and catalyst.

8. The process of claim 1 , wherein the separating of the one more of solids, molten metals, and acid gases from the cooled PDX product stream comprises passing the cooled PDX product stream through a particle filter and a water scrubber.

9. The process of claim 1 , wherein the first fraction stream exiting the catalytic water gas shift reactor has an H 2 to CO ratio of about 5:1 to about 1:1.

10. The process of claim 1 , wherein the PDX fuel stream passed through the PDX heat exchanger is cooled against a cooling stream comprising one or more of:
a high pressure recycle fluid stream withdrawn from and returned to the PPS;
a high pressure water stream;
a nitrogen stream;
a stream of PDX reactor liquid fuel feed;
a high pressure stream of O 2 and CO 2 ; and
a stream of cleaned and cooled PDX fuel gas.

11. The process of claim 1 , wherein prior to compressing the filtered PDX fuel gas stream to a pressure of about 12 MPa or greater, at least a portion of the filtered PDX fuel gas stream is passed through one or both of a mercury removal unit and an acid gas removal unit.

12. The process of claim 11 , wherein at least a portion of the filtered PDX fuel gas stream is passed through an activated, sulfur-impregnated, carbon bed adsorption system configured to remove mercury from the PDX fuel gas.

13. The process of claim 11 , wherein at least a portion of the filtered PDX fuel gas stream is passed through an acid gas removal unit configured to remove part or substantially all of at least one of H 2 S and CO 2 from the filtered PDX fuel gas stream.

14. The process of claim 1 , wherein prior to the step of compressing the filtered PDX fuel gas stream to a pressure of about 12 MPa or greater, at least a portion of the filtered PDX fuel gas stream is passed through a methanation unit configured to convert CO and H 2 to CH 4 and H 2 O.

15. The process of claim 14 , wherein the methanation unit is a catalytic unit, and optionally wherein methanation is carried out using a nickel-based catalyst.

16. The process of claim 14 , wherein the methane-enriched PDX fuel gas exiting the methanation unit has a methane content of about 50% or greater by volume.

17. The process of claim 14 , comprising passing the methane-enriched PDX fuel gas exiting the methanation unit through a post-methanation heat exchanger against a cooling stream, optionally wherein the cooling stream comprises one or more of: a high pressure recycle fluid stream withdrawn from and returned to the PPS; a high pressure water stream; a nitrogen stream; a high pressure stream of O 2 and CO 2 ; a stream of PDX reactor liquid fuel feed; and a stream of cleaned and cooled PDX fuel gas.

18. The process of claim 14 , comprising passing the methane-enriched PDX fuel gas stream from the methanation unit to a separator wherein at least a portion of any water produced in the methanation reactor is removed.

19. The process of claim 1 , wherein after compressing the filtered PDX fuel gas stream to a pressure of about 12 MPa or greater and prior to combusting the filtered and compressed PDX fuel gas in the PPS combustor, the process comprises heating the filtered and compressed PDX fuel gas by passage through the PDX heat exchanger.

20. The process of claim 1 , further comprising:
passing the expanded PPS combustion product stream through a PPS recuperator heat exchanger and thereby withdrawing heat from the PPS combustion product stream and forming a cooled PPS combustion product stream;
optionally passing the cooled PPS combustion product stream through a water cooler;
treating the cooled PPS combustion product stream in a PPS scrubber to form a recycle CO 2 stream by removing substantially all nonCO 2 components; and
pressurizing the recycle CO 2 stream in a PPS compressor to form a compressed recycle CO 2 stream.

Assignees

• 8 Rivers Capital Llc

Inventors

• Forrest Brock Alan
• Lu Xijia

Classifications

• C07C1/0435

  containing a metal of group 8 or a compound thereof · CPC title

• C10J2300/1846

  Partial oxidation, i.e. injection of air or oxygen only · CPC title

• C07C2523/755

  Nickel · CPC title

• C01B2203/1235

  Hydrocarbons · CPC title

• C10J2300/093

  Coal · CPC title