Energy storage using an REP with an engine

Patent metadata

Field	Value
Publication number	US-10680265-B2
Application number	US-201815980305-A
Country	US
Kind code	B2
Filing date	May 15, 2018
Priority date	Nov 16, 2015
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

An energy storage system includes a power plant configured to generate an exhaust gas comprising carbon dioxide. The energy storage system further includes a first fuel cell configured to operate in reverse as an electrolyzer. The first fuel cell is configured to receive at least a portion of the exhaust gas from the power plant. An anode is configured to receive carbon dioxide via the exhaust gas and methane from a separate feed, and the anode is configured to output a hydrogen-containing gas mixture. The energy storage system further includes a reformer configured to methanate the hydrogen-containing gas mixture to convert substantially all of the carbon monoxide in the hydrogen-containing gas mixture to methane. The energy storage system further includes a second fuel cell operating in reverse as a hydrogen pump, the second fuel cell configured to separate hydrogen from a gas mixture output by the reformer.

First claim

What is claimed is:

1. An energy storage system comprising:
a power plant configured to generate an exhaust gas comprising carbon dioxide;
a first fuel cell comprising:
an anode and a cathode separated by an electrolyte matrix; and
wherein the first fuel cell is configured to receive at least a portion of the exhaust gas from the power plant;
wherein the anode is configured to receive carbon dioxide via the exhaust gas and to also receive methane from a separate feed; and
wherein the anode is configured to output a hydrogen-containing gas mixture comprising hydrogen and carbon monoxide;

a power supply configured to apply a reverse voltage to the first fuel cell to operate the first fuel cell in reverse as an electrolyzer;
a reformer configured to methanate the hydrogen-containing gas mixture output from the anode of the first fuel cell to convert substantially all of the carbon monoxide in the hydrogen-containing gas mixture to methane, wherein the reformer is configured to output a gas mixture; and
a second fuel cell operating in reverse as a hydrogen pump, the second fuel cell configured to separate hydrogen from the gas mixture output by the reformer.

2. The energy storage system according to claim 1 , wherein the cathode of the first fuel cell is configured to receive the exhaust gas from the power plant.

3. The energy storage system according to claim 1 , wherein the power plant is an internal combustion engine.

4. The energy storage system according to claim 1 , wherein the feed comprises methane and carbon dioxide; and
wherein an amount of hydrogen output by the second fuel cell is proportional to an amount of carbon supplied by the feed.

5. The energy storage system according to claim 1 , wherein the cathode of the first fuel cell is configured to receive a gas mixture output from an anode of the second fuel cell.

6. The energy storage system according to claim 1 , wherein the reformer is further configured to convert carbon dioxide that is included in the hydrogen-containing gas output by the first fuel cell to methane.

7. The energy storage system according to claim 1 , wherein the second fuel cell is configured to compress hydrogen-containing gas using an electrochemical hydrogen compressor to output purified hydrogen gas.

8. An energy storage system comprising:
a power plant configured to output an REP cathode feed gas;
a fuel cell comprising:
an anode and a cathode separated by an electrolyte matrix; and
wherein the anode is configured to receive an REP anode feed gas comprising carbon dioxide; and
wherein the fuel cell is configured to output a hydrogen-containing gas mixture comprising hydrogen and carbon dioxide;

a power supply configured to apply a reverse voltage to the fuel cell to operate the fuel cell in reverse as an electrolyzer;
a reformer configured to methanate the hydrogen-containing gas mixture output from the fuel cell, such that carbon dioxide is convened to methane, the reformer configured to output a converted hydrogen-containing gas mixture; and
a compressor configured to compress the convened hydrogen-containing gas mixture from the reformer.

9. The energy storage system according to claim 8 , wherein the REP anode feed gas further comprises a hydrocarbon.

10. The energy storage system according to claim 8 , wherein the power plant is an internal combustion engine.

11. The energy storage system according to claim 8 , wherein the REP cathode feed gas is exhaust gas from the power plant.

12. The energy storage system according to claim 8 , wherein the reformer is configured to convert carbon monoxide and carbon dioxide in the hydrogen-containing gas mixture output by the fuel cell into methane.

13. The energy storage system according to claim 8 , wherein the compressor is configured to compress methane in the converted hydrogen-containing gas mixture from the reformer.

14. The energy storage system according to claim 13 , wherein compressed methane and the converted hydrogen-containing gas mixture from the compressor are cooled, such that water is condensed and separated from the converted hydrogen-containing gas mixture.

15. The energy storage systems according to claim 8 , wherein methane produced in the energy storage system is configured to be inserted into a pipeline.

16. The energy storage system according to claim 15 , further comprising a water knockout pot configured to remove condensed water from the methane output stream.

17. The energy storage system according to claim 15 , wherein compressed methane output from the compressor is configured to be stored.

18. The energy storage system according to claim 8 , wherein the power plant is configured to receive an anaerobic digester gas and a mixture of carbon dioxide and methane.

Assignees

• Fuelcell Energy Inc

Inventors

• Jahnke Fred C
• Lambrech Matthew

Classifications

• H01M2250/407

  Combination of fuel cells with mechanical energy generators · CPC title

• C01B2203/0233

  the reforming step being a steam reforming step · CPC title

• H01M16/003

  of fuel cells with other electrochemical devices, e.g. capacitors, electrolysers · CPC title

• C25B1/00

  Electrolytic production of inorganic compounds or non-metals · CPC title

• H01M8/0612 Primary

  from carbon-containing material · CPC title