System including fuel cell assembly voltage monitor

Patent metadata

Field	Value
Publication number	US-11545684-B2
Application number	US-202117198771-A
Country	US
Kind code	B2
Filing date	Mar 11, 2021
Priority date	Sep 12, 2018
Publication date	Jan 3, 2023
Grant date	Jan 3, 2023

Abstract

A system for capturing carbon dioxide in flue gas includes a fuel cell assembly including at least one fuel cell including a cathode portion configured to receive, as cathode inlet gas, the flue gas generated by the flue gas generating device or a derivative thereof, and to output cathode exhaust gas and an anode portion configure to receive an anode inlet gas and to output anode exhaust gas, a fuel cell assembly voltage monitor configured to measure a voltage across the fuel cell assembly, and a controller configured to receive the measured voltage across the fuel cell assembly from the fuel cell assembly voltage monitor, determine an estimated carbon dioxide utilization of the fuel cell assembly based on the measured voltage across the fuel cell assembly, and reduce the carbon dioxide utilization of the fuel cell assembly when the determined estimated carbon dioxide utilization is above a predetermined threshold utilization.

First claim

What is claimed is:

1. A system for capturing carbon dioxide in flue gas generated by a flue gas generating device, the system comprising:
a fuel cell assembly comprising at least one fuel cell comprising:
a cathode portion configured to receive, as cathode inlet gas, the flue gas generated by the flue gas generating device or a derivative thereof, and to output cathode exhaust gas, and
an anode portion configured to receive an anode inlet gas and to output anode exhaust gas;

a fuel cell assembly voltage monitor configured to measure a voltage across the fuel cell assembly;
a controller configured to:
receive the measured voltage across the fuel cell assembly from the fuel cell assembly voltage monitor,
determine an estimated carbon dioxide utilization of the fuel cell assembly based on at least the measured voltage across the fuel cell assembly, and
when the determined estimated carbon dioxide utilization is above a predetermined threshold utilization, reduce a carbon dioxide utilization of the fuel cell assembly; and

an anode exhaust processor configured to:
receive the anode exhaust gas,
provide an anode exhaust gas return portion of the anode exhaust gas to an anode exhaust gas return line that is configured to provide the anode exhaust gas return portion to an anode gas oxidizer in a manner that is controllable by the controller,
provide an anode exhaust gas recycle portion of the anode exhaust gas to an anode exhaust gas recycle line that is configured to provide the anode exhaust gas recycle portion to the anode section of the fuel cell assembly in a manner that is controllable by the controller,
provide carbon dioxide separated from the anode exhaust gas to a carbon dioxide product line in a manner that is controllable by the controller, and
provide water separated from the anode exhaust gas to a water product line in a manner that is controllable by the controller.

2. The system of claim 1 , wherein:
the controller is configured to determine the estimated carbon dioxide utilization by performing steps comprising:
determining an expected voltage across the fuel cell assembly based on at least (i) a temperature of the fuel cell assembly, (ii) a current density across the fuel cell assembly, (iii) a fuel utilization of the fuel cell assembly, and (iv) a cathode oxygen utilization of the fuel cell assembly, and
determining the estimated carbon dioxide utilization based on a comparison between the measured voltage across the fuel cell assembly and the determined expected voltage across the fuel cell assembly.

3. The system of claim 2 , further comprising:
at least one temperature sensor configured to measure temperatures within the fuel cell assembly,
wherein the controller is configured to determine an average temperature of the fuel cell assembly based on the temperatures measured by the at least one temperature sensor.

4. The system of claim 2 , further comprising:
a load controller configured to measure a current across the fuel cell assembly,
wherein the controller is configured to determine the current density across the fuel cell based on at least the current across the fuel cell assembly as measured by the load controller.

5. The system of claim 2 , further comprising:
a flow transmitter, wherein:
the anode inlet gas comprises a fuel gas flow,
the flow transmitter is configured to measure a flow rate of the fuel gas flow;
wherein the controller is configured to determine the fuel utilization of the fuel cell assembly based on at least the flow rate of the fuel gas flow as measured by the flow transmitter.

6. The system of claim 2 , further comprising:
a hydrogen gas analyzer configured to measure a hydrogen content of the anode exhaust gas,
wherein the controller is configured to determine the fuel utilization of the fuel cell assembly based on at least the hydrogen concentration in the anode exhaust gas as measured by the hydrogen gas analyzer.

7. The system of claim 2 , further comprising:
a cathode inlet gas flow transmitter configured to measure a flow rate of the cathode inlet gas; and
a cathode inlet gas analyzer configured to measure a composition of the cathode inlet gas,
wherein the controller is configured to determine a cathode oxygen utilization based on at least the flow rate of the cathode inlet gas as measured by the cathode inlet gas flow transmitter, and the composition of the cathode inlet gas as measured by the cathode inlet gas analyzer.

8. The system of claim 1 , further comprising:
a cathode outlet gas flow transmitter configured to measure a flow rate of the cathode outlet gas; and
a cathode outlet gas analyzer configured to measure a composition of the cathode outlet gas,
wherein the controller is configured to determine the cathode oxygen utilization based on at least the flow rate of the cathode outlet gas as measured by the cathode outlet gas flow transmitter, and the composition of the cathode outlet gas as measured by the cathode outlet gas analyzer.

9. The system of claim 1 , further comprising:
a cathode inlet gas flow transmitter configured to measure a flow rate of the cathode inlet gas;
a cathode inlet gas analyzer configured to measure a composition of the cathode inlet gas,
a cathode outlet gas flow transmitter configured to measure a flow rate of the cathode outlet gas; and
a cathode outlet gas analyzer configured to measure a composition of the cathode outlet gas,
wherein the controller is configured to determine the cathode oxygen utilization based on at least the flow rate of the cathode inlet gas as measured by the cathode inlet gas flow transmitter, the composition of the cathode inlet gas as measured by the cathode inlet gas analyzer, the flow rate of the cathode outlet gas as measured by the cathode outlet gas flow transmitter, and the composition of the cathode outlet gas as measured by the cathode outlet gas analyzer.

10. The system of claim 1 , further comprising:
a flue gas blower configured to receive flue gas from the flue gas generating device and output the flue gas,
wherein the controller is configured to, when the determined estimated carbon dioxide utilization is above the predetermined threshold utilization, reduce the carbon dioxide utilization of the fuel cell assembly by at least controlling the flue gas blower to increase a flow rate of the flue gas, or the derivative thereof, provided to the cathode portion of the fuel cell assembly.

11. The system of claim 1 , further comprising:
a load controller configured to control a current across the fuel cell assembly,
wherein the controller is configured to, when the determined estimated carbon dioxide utilization is above the predetermined threshold utilization, reduce the carbon dioxide utilization of the fuel cell assembly by at least controlling the load controller to reduce the current across the fuel cell assembly.

12. The system of claim 1 , wherein the controller is configured to, when the determined estimated carbon dioxide utilization is above the predetermined threshold utilization, reduce the carbon dioxide utilization of the fuel cell assembly by at least controlling the anode exhaust processor to reduce an amount of carbon dioxide product provided to the carbon dioxide product line, and increase an amount of the anode exhaust gas return portion provided to the cathode portion of the fuel cell assembly via the anode exhaust gas return line.

13. The system of claim 1 , further comprising:
at least one valve configured to adjust an amount of anode inlet gas provided to the anode section of the fuel cell assembly.

14. The system of claim 1 , w

Assignees

• Fuelcell Energy Inc

Inventors

• Daly Joseph Michael
• Jolly Stephen
• Venkataraman Ramakrishnan
• Nuhfer Eric

Classifications

• H01M8/04365

  of other components of a fuel cell or fuel cell stacks · CPC title

• H01M8/04589

  of fuel cell stacks · CPC title

• H01M8/04097

  with recycling of the reactants (H01M8/04119, H01M8/04104 take precedence) · CPC title

• H01M8/04402

  of anode exhausts · CPC title

• H01M8/04761

  of fuel cell exhausts · CPC title