Supercritical CO2 cycle coupled to chemical looping arrangement

Patent metadata

Field	Value
Publication number	US-11041410-B2
Application number	US-201916715863-A
Country	US
Kind code	B2
Filing date	Dec 16, 2019
Priority date	Jun 26, 2018
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

Systems and methods for coupling a chemical looping arrangement and a supercritical CO2 cycle are provided. The system includes a fuel reactor, an air reactor, a compressor, first and second heat exchangers, and a turbine. The fuel reactor is configured to heat fuel and oxygen carriers resulting in reformed or combusted fuel and reduced oxygen carriers. The air reactor is configured to re-oxidize the reduced oxygen carriers via an air stream. The air stream, fuel, and oxygen carriers are heated via a series of preheaters prior to their entry into the air and fuel reactors. The compressor is configured to increase the pressure of a CO2 stream to create a supercritical CO2 stream. The first and second heat exchangers are configured to heat the supercritical CO2 stream, and the turbine is configured to expand the heated supercritical CO2 stream to generate power.

First claim

What is claimed is:

1. A system for employing a supercritical CO 2 cycle, wherein the supercritical CO 2 cycle is coupled to a fuel reactor and an air reactor fluidly connected to the fuel reactor, wherein fuel reacts with oxygen carriers in the fuel reactor to form reformed or combusted fuel and reduced oxygen carriers, and wherein the reduced oxygen carriers are oxidized via an air stream in the air reactor to form re-oxidized oxygen carriers and oxygen-depleted air, the system comprising:
a compressor configured to receive a CO 2 stream from a CO 2 source, wherein the compressor is configured to increase the pressure of the CO 2 stream thereby creating a high pressure supercritical CO 2 stream;
a first heat exchanger in fluid communication with the compressor and the fuel reactor, the first heat exchanger being configured to receive and heat the supercritical CO 2 stream, and being configured to receive at least a portion of the reformed or combusted fuel from the fuel reactor, wherein the energy from the reformed or combusted fuel is used to heat the supercritical CO 2 stream;
a second heat exchanger in fluid communication with the first heat exchanger and the air reactor, the second heat exchanger being configured to receive and further heat the supercritical CO 2 stream received from the first heat exchanger, and being configured to receive the oxygen-depleted air and a portion of the re-oxidized oxygen carriers from the air reactor, wherein the energy from the oxygen-depleted air and the portion of the re-oxidized oxygen carriers is used to heat the supercritical CO 2 stream; and
a turbine in fluid communication with the second heat exchanger, the turbine being configured to receive the supercritical CO 2 stream from the second heat exchanger and expand the supercritical CO 2 , whereby the expansion of the supercritical CO 2 generates power, and wherein the turbine comprises an outlet for the expanded supercritical CO 2 .

2. The system of claim 1 , wherein the expanded supercritical CO 2 is used to heat the fuel and the air stream prior to their respective deliveries to the fuel reactor and the air reactor.

3. The system of claim 2 , further comprising:
a first conduit in fluid communication with the turbine and configured to receive a first portion of the expanded supercritical CO 2 from the turbine;
a second conduit in fluid communication with the turbine and configured to receive a second portion of the expanded supercritical CO 2 from the turbine;
an air preheater in fluid communication with the first conduit, an air source for the air stream, and the air reactor, the air preheater being configured to heat the air stream using the energy of the first portion of the expanded supercritical CO 2 prior to delivery of the air stream to the air reactor; and
a first fuel preheater in fluid communication with the second conduit, a fuel source for the fuel, and the fuel reactor, the first fuel preheater being configured to heat the fuel using the energy of the second portion of the expanded supercritical CO 2 prior to delivery of the fuel to the fuel reactor,
wherein the heating of the air stream in the air preheater and the fuel in the first fuel preheater by the respective portions of expanded supercritical CO 2 results in respective low-pressure streams of CO 2 .

4. The system of claim 3 , further comprising:
a cooler in fluid communication with the air preheater and the first fuel preheater, the cooler being configured to receive the respective low-pressure streams of CO 2 from the air preheater and the first fuel preheater and cool the received low pressure CO 2 , and
a third conduit in fluid communication with the cooler and the compressor, the third conduit being configured to receive the cooled low-pressure CO 2 and transfer the cooled low-pressure CO 2 to the compressor.

5. The system of claim 3 , further comprising a second fuel preheater in fluid communication with the fuel reactor, the first fuel preheater and the first heat exchanger, the second fuel preheater being configured to:
receive the fuel delivered from the first fuel preheater and at least a portion of the reformed or combusted fuel from the fuel reactor; and
further heat the fuel via energy from the reformed or combusted fuel prior to the delivery of the fuel to the fuel reactor.

6. The system of claim 1 , further comprising a solids preheater in fluid communication with the fuel reactor, the solids preheater being configured to receive a portion of the reformed or combusted fuel from the fuel reactor and to heat the oxygen carriers using the energy of the reformed or combusted fuel prior to delivery of the oxygen carriers to the fuel reactor.

7. The system of claim 6 , wherein the resulting fuel following reaction in the fuel reactor is a reformed fuel, and wherein the system further comprises:
a fuel cooler in fluid communication with the solids preheater and the first heat exchanger, the fuel cooler being configured to receive the reformed fuel from the solids preheater and the first heat exchanger, and to cool the received reformed fuel to about ambient temperature;
a second compressor in fluid communication with the fuel cooler, the second compressor being configured to compress the ambient temperature reformed fuel received from the fuel cooler;
a combustion chamber in fluid communication with the second compressor and the turbine, the combustion chamber being configured to combust the compressed reformed fuel received from the second compressor to generate a stream of CO 2 and water vapor, and to feed the stream of generated CO 2 and water vapor to the turbine; and
a gas processing unit in fluid communication with the turbine and downstream of the fuel cooler, the gas processing unit being configured to separate the stream of generated CO 2 and the water vapor received from the turbine from a low pressure CO 2 stream received from the turbine.

8. The system of claim 1 , further comprising at least one controller configured to operate the fuel reactor in a temperature range of about 800° C. to about 1100° C. and configured to operate the air reactor in a temperature range of about 900° C. to about 1200° C.

9. The system of claim 1 , wherein the compressor is a multistage compressor having intercooling stages, wherein the intercooling stages enable compression of CO 2 from a low-pressure side of the supercritical CO 2 cycle and transfer of the compressed CO 2 to a high-pressure side of the supercritical CO 2 cycle.

10. A method for generating power via a supercritical CO 2 cycle, wherein the supercritical CO 2 cycle is coupled to a fuel reactor and an air reactor fluidly connected to the fuel reactor, wherein fuel reacts with oxygen carriers in the fuel reactor to form reformed or combusted fuel and reduced oxygen carriers, and wherein the reduced oxygen carriers are oxidized via an air stream in the air reactor to form re-oxidized oxygen carriers and oxygen-depleted air, the method comprising:
introducing a CO 2 stream into a compressor, wherein the compressor is configured to increase the pressure of the CO 2 stream to create a supercritical CO 2 stream;
transferring both the supercritical CO 2 stream from the compressor and the reformed or combusted fuel from the fuel reactor to a first heat exchanger, which operates to transfer heat from the reformed or combusted fuel to the supercritical CO 2 stream;
transferring a) the supercritical CO 2 stream from the first heat exchanger, b) the oxygen-depleted air from the air reactor, and c) a portion of the re-oxidized oxygen carriers from the air reactor to a second heat exchanger, which operates to transfer heat from the oxygen-depleted air an

Assignees

• Saudi Arabian Oil Co

Inventors

• Younes Mourad
• Harale Aadesh
• Jamal Aqil

Classifications

• F23C10/01

  in a fluidised bed of catalytic particles · CPC title

• F02C1/10

  Closed cycles · CPC title

• F23C2900/99008

  Unmixed combustion, i.e. without direct mixing of oxygen gas and fuel, but using the oxygen from a metal oxide, e.g. FeO · CPC title

• F23C2206/103

  Cooling recirculating particles · CPC title

• F02C1/02

  the working fluid being an unheated pressurised gas · CPC title