Oxygen transport membrane based advanced power cycle with low pressure synthesis gas slip stream

• US 9,453,644 B2
• Filed: 12/23/2013
• Issued: 09/27/2016
• Est. Priority Date: 12/28/2012
• Status: Active Grant

• Current Assignee: Praxair Technology Incorporated (Linde Plc)
• Original Assignee: Praxair Technology Incorporated (Linde Plc)
• Inventors: Kromer, Brian R., Litwin, Michael M., Kelly, Sean M.
• Primary Examiner(s): Walczak, David
• Application Number:
  US14/138,619
• Publication Number:
  US 20140183866A1
• Time in Patent Office: 1,009 Days
• US Class Current: 1/1
• CPC Class Codes: F01K 13/006 Auxiliaries or details not otherwise provided for
• CPC Class Codes: F01K 23/067 the combustion heat coming from a gasification or pyrolysis process, e.g. coal gasification gas turbines with fuel gasifiers F02C3/28
• CPC Class Codes: F01K 23/16 all the engines being turbines F01K23/14 takes precedence
• CPC Class Codes: F01K 7/16 the engines being only of turbine type the engines using steam of critical or overcritical pressure F01K7/32; the engines being of extraction or non-condensing type F01K7/34
• CPC Class Codes: F23C 2900/99011 Combustion process using synthetic gas as a fuel, i.e. a mixture of CO and H2
• CPC Class Codes: F23L 15/04 Arrangements of recuperators
• CPC Class Codes: F23L 7/007 Supplying oxygen or oxygen-enriched air
• CPC Class Codes: Y02E 20/18 Integrated gasification combined cycle [IGCC], e.g. combined with carbon capture and storage [CCS]
• CPC Class Codes: Y02E 20/34 Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery

Abstract

A method and system for generating electrical power in which a high pressure synthesis gas stream generated in a gasifier is partially oxidized in an oxygen transport membrane based reactor, expanded and thereafter, is combusted in an oxygen transport membrane based boiler. A low pressure synthesis gas slip stream is split off downstream of the expanders and used as the source of fuel in the oxygen transport membrane based partial oxidation reactors to allow the oxygen transport membrane to operate at low fuel pressures with high fuel utilization. The combustion within the boiler generates heat to raise steam to in turn generate electricity by a generator coupled to a steam turbine. The resultant flue gas can be purified to produce a carbon dioxide product.

Claims

1. A method of generating electrical power comprising the steps of:

generating a synthesis gas stream in a gasifier;

heating the synthesis gas stream via indirect heat exchange with radiant heat generated from at least one oxygen transport membrane based partial oxidation reactor;

expanding the heated synthesis gas stream in at least one expansion stage;

diverting a portion of the expanded synthesis gas stream to the at least one oxygen transport membrane based partial oxidation reactor where such diverted portion of the synthesis gas stream is partially oxidized with permeated oxygen from the oxygen transport membrane based partial oxidation reactor to produce a reaction product stream and the radiant heat;

feeding another portion of the expanded synthesis gas stream and the reaction product stream to an oxygen transport membrane based boiler where the synthesis gas stream and reaction product stream react with permeated oxygen and a source of supplemental oxygen to produce steam from a source of boiler feed water and to produce a carbon dioxide containing flue gas stream;

extracting energy from the steam by a steam turbine subsystem operatively associated with the oxygen transport membrane based boiler and converting the extracted energy to electrical power; and

purifying the carbon dioxide containing flue gas stream to produce a carbon dioxide-rich stream.

2. The method of claim 1 further comprising coupling a generator to the at least one expansion stage and generating electrical power from the generator.

3. The method of claim 2 wherein the at least one expansion stage further comprises a first expansion stage having a first expander and a second expansion stage having a second expander wherein electrical power is generated from one or more generators coupled to the first and second expanders.

4. The method of claim 1 wherein the steps of heating the synthesis gas stream and expanding the heated synthesis gas stream further comprise:

heating the synthesis gas stream via indirect heat exchange with radiant heat generated from a first oxygen transport membrane based partial oxidation reactor;

expanding the heated synthesis gas stream in a first expander;

further heating the expanded synthesis gas stream via indirect heat exchange with radiant heat generated from a second oxygen transport membrane based partial oxidation reactor; and

further expanding the further heated synthesis gas stream in a second expander.

5. The method of claim 4 wherein the steps of diverting a portion of the expanded synthesis gas stream and feeding streams to the boiler further comprise:

diverting a portion of the expanded synthesis gas stream or further expanded synthesis gas stream to the oxygen transport membrane based partial oxidation reactors where such diverted portions of the synthesis gas stream are partially oxidized with permeated oxygen from the oxygen transport membrane based partial oxidation reactors to produce reaction product streams and the radiant heat; and

feeding the further expanded synthesis gas stream and the reaction product streams to the boiler to produce the steam.

6. The method of claim 1 wherein the source of supplemental oxygen is cryogenically produced oxygen from an air separation unit.

7. The method of claim 1 wherein the boiler is an oxygen transport membrane based boiler that reacts a portion of the synthesis gas stream with oxygen permeated through at least one oxygen transport membrane element to produce the difference in oxygen partial pressure across the at least one oxygen transport membrane element and generate the source of heat within the boiler required to produce the steam and the carbon dioxide containing flue gas stream.

8. An oxygen transport membrane based advanced power cycle system comprising:

a source of high pressure synthesis gas;

at least one oxygen transport membrane based partial oxidation reactor having one or more oxygen transport membrane elements and one or more metal tubes containing the synthesis gas and disposed adjacent or juxtaposed to the one or more oxygen transport membrane elements, the at least one oxygen transport membrane based partial oxidation reactor configured to heat the synthesis gas stream in the metal tubes via indirect heat exchange with a first source of radiant heat generated from a partial oxidation of a low pressure synthesis gas slip stream with oxygen permeated through the one or more oxygen transport membrane elements, and wherein the partial oxidation further produces a reaction product stream and the first source of radiant heat;

at least one expander disposed downstream of the at least one oxygen transport membrane based partial oxidation reactor, the expander configured to expand the heated synthesis gas stream to produce energy and reduce the pressure of the synthesis gas stream;

a recycle conduit configured to divert a portion of the expanded synthesis gas stream to the at least one oxygen transport membrane based partial oxidation reactor where such diverted portion of the synthesis gas stream is the low pressure synthesis gas slip stream that is partially oxidized with the permeated oxygen;

an oxygen transport membrane based boiler having one or more oxygen transport membrane elements and one or more steam tubes containing the boiler feed water and disposed adjacent or juxtaposed to the one or more oxygen transport membrane elements in the oxygen transport membrane based boiler, the oxygen transport membrane based boiler configured to heat the boiler feed water in the steam tubes to produce steam via indirect heat exchange with a second source of radiant heat generated from a combustion of the low pressure synthesis gas with oxygen permeated through the one or more oxygen transport membrane elements, and wherein the combustion produces the second source of radiant heat;

wherein the oxygen transport membrane based boiler is further configured to combust any expanded synthesis gas stream with a source of supplemental oxygen to produce a carbon dioxide containing flue gas and to further heat the boiler feed water in the steam tubes to produce steam; and

a steam turbine subsystem operatively associated with the oxygen transport membrane based boiler and configured to convert the steam to electrical power.

9. The system of claim 8 further comprising a carbon dioxide purification subsystem configured to purify the carbon dioxide containing flue gas stream and produce a carbon dioxide-rich stream.

10. The system of claim 8 further comprising:

an air supply and preheat subsystem that includes an oxygen containing feed stream;

a regenerative air preheater configured to heat the oxygen containing feed stream;

a plurality of conduits for supplying the heated oxygen containing feed stream from the regenerative air preheater to the oxygen transport membrane based partial oxidation reactors and the oxygen transport membrane based boiler; and

a plurality of return conduits configured to return a heated, oxygen depleted stream from the oxygen transport membrane based partial oxidation reactors and the oxygen transport membrane based boiler to the regenerative air preheater to heat oxygen containing feed stream.

11. The system of claim 10 further comprising a reactor housing configured to contain the at least one oxygen transport membrane based partial oxidation reactor and the oxygen transport membrane based boiler.

12. The system of claim 11 wherein the oxygen transport membrane elements are oxygen transport membrane tubes and the oxygen containing feed stream is supplied to the interior of the oxygen transport membrane tubes while the low pressure synthesis gas slip stream is supplied to the at least one oxygen transport membrane based partial oxidation reactor and the oxygen transport membrane based boiler via a common duct or passage through the reactor housing and the oxygen containing feed stream is supplied to the interior of the oxygen transport membrane tubes.

13. The system of claim 8 further comprising a generator operatively coupled to the at least one expander and configured to generate electrical power from the expansion of the heated synthesis gas.

14. The system of claim 8 wherein the supplemental oxygen is oxygen produced from an air separation unit.

15. The system of claim 8 wherein the at least one oxygen transport membrane based partial oxidation reactor and the at least one expander and further comprise:

a first oxygen transport membrane based partial oxidation reactor configured to heat the synthesis gas stream in adjacent metal tubes via indirect heat exchange with radiant heat generated from a partial oxidation of a low pressure synthesis gas slip stream with oxygen permeated through the one or more oxygen transport membrane elements in the first oxygen transport membrane based partial oxidation reactor;

a first turbo-expander disposed downstream of the first oxygen transport membrane based partial oxidation reactor, the first turbo-expander configured to expand the heated synthesis gas stream to an intermediate pressure;

a second oxygen transport membrane based partial oxidation reactor configured to further heat the heated synthesis gas stream in adjacent metal tubes via indirect heat exchange with radiant heat generated from a partial oxidation of a low pressure synthesis gas slip stream with oxygen permeated through the one or more oxygen transport membrane elements in the second oxygen transport membrane based partial oxidation reactor; and

a second turbo-expander disposed downstream of the second oxygen transport membrane based partial oxidation reactor, the second turbo-expander configured to expand the heated synthesis gas stream to near atmospheric pressure.