System and method for producing hydrogen using high temperature fuel cells

Patent metadata

Field	Value
Publication number	US-11444303-B2
Application number	US-202017017244-A
Country	US
Kind code	B2
Filing date	Sep 10, 2020
Priority date	Mar 16, 2018
Publication date	Sep 13, 2022
Grant date	Sep 13, 2022

Abstract

A steam methane reformer-integrated fuel cell system includes at least one fuel cell having an anode, a cathode, and an electrolyte matrix separating the anode and the cathode. The system further includes a steam methane reformer configured to react methane with steam to produce a first product stream including hydrogen (H 2 ), carbon dioxide (CO 2 ), and carbon monoxide (CO).

First claim

What is claimed is:

1. A steam methane reformer-integrated fuel cell system, comprising:
at least one fuel cell comprising:
an anode;
a cathode; and
an electrolyte matrix separating the anode and the cathode;

a flash gas apparatus configured to receive rich solvent from an absorber column and configured to produce a first CO 2 -rich flashed gas stream;
an anode gas oxidizer (AGO) configured to receive a mixture of anode exhaust gas from the at least one fuel cell, a preheated air stream, and the first CO 2 -rich flashed gas stream, such that the anode exhaust gas reacts with the preheated air stream to produce a high-temperature exhaust stream, and configured to provide the high-temperature exhaust stream to the cathode of the at least one fuel cell; and
a steam methane reformer configured to utilize heat from the high-temperature exhaust stream output from the AGO and to react methane with steam to produce a first product stream including hydrogen (H 2 ), carbon dioxide (CO 2 ), and carbon monoxide (CO).

2. The system of claim 1 , wherein:
the first product stream comprises a first concentration of hydrogen, and
the system further comprises a water-gas shift reactor configured to react CO in the first product stream with steam to produce an outlet stream having a second concentration of hydrogen which is greater than the first concentration of hydrogen.

3. The system of claim 2 , wherein the absorber column is configured to reduce a concentration of CO 2 in the outlet stream such that a second product stream of the absorber column has a third concentration of hydrogen which is greater than the second concentration of hydrogen.

4. The system of claim 3 , further comprises a pressure swing adsorption (PSA) system configured to purify the second product stream such that a third product stream of the PSA purification system has a fourth concentration of hydrogen which is greater than the third concentration of hydrogen.

5. The system of claim 4 , wherein the fourth concentration of hydrogen is at least 95 mole %.

6. The system of claim 3 , wherein the third concentration of hydrogen is at least 90 mole %.

7. The system of claim 2 , wherein the second concentration of hydrogen is at least 70 mole %.

8. The system of claim 4 , wherein the at least one fuel cell is configured to receive a PSA tail gas from the PSA purification system as an anode feed gas.

9. The system of claim 4 , further comprising a stripper column connected to the absorber column; wherein:
the stripper column is configured to receive a PSA tail gas from the PSA purification system and a solvent from the absorber column; and
the stripper column is configured to strip CO 2 from the solvent using the PSA tail gas and output a CO 2 -stripped solvent.

10. The system of claim 9 , wherein the absorber column is configured to receive the CO 2 -stripped solvent from the stripper column, such that the hydrogen concentration of the second product stream increases from the second concentration to the third concentration.

11. The system of claim 1 , wherein the first CO 2 -rich flashed gas stream comprises at least 60 mole % CO 2 .

12. The system of claim 11 , wherein the first CO 2 -rich flashed gas stream is produced by a low-pressure flash system.

13. The system of claim 11 , further comprising a two-pressure flash system configured to produce the first CO 2 -rich flashed gas stream, the two-pressure flash system comprising:
a medium-pressure flash apparatus; and
a low-pressure flash apparatus;
wherein the medium-pressure flash apparatus is configured to operate at a pressure in a range of 40% to 60% of a pressure in the absorber column.

14. A steam methane reformer-integrated fuel cell system, comprising:
at least one fuel cell comprising:
an anode;
a cathode; and
an electrolyte matrix separating the anode and the cathode;

a steam methane reformer configured to react methane with steam to produce a first product stream including a first concentration of hydrogen (H 2 ), carbon dioxide (CO 2 ), and carbon monoxide (CO);
a water-gas shift reactor configured to react CO in the first product stream with steam to produce an outlet stream having a second concentration of hydrogen which is greater than the first concentration of hydrogen;
an absorber column configured to reduce a concentration of CO 2 in the outlet stream such that a second product stream of the absorber column has a third concentration of hydrogen which is greater than the second concentration of hydrogen;
a pressure swing adsorption (PSA) system configured to purify the second product stream such that a third product stream of the PSA purification system has a fourth concentration of hydrogen which is greater than the third concentration of hydrogen; and
a stripper column connected to the absorber column; wherein:
the stripper column is configured to receive a PSA tail gas from the PSA purification system and a solvent from the absorber column; and
the stripper column is configured to strip CO 2 from the solvent using the PSA tail gas and output a CO 2 -stripped solvent.

15. The system of claim 14 , wherein the absorber column is configured to receive the CO 2 -stripped solvent from the stripper column, such that the hydrogen concentration of the second product stream increases from the second concentration to the third concentration.

Assignees

• Fuelcell Energy Inc

Inventors

• Jahnke Fred C
• Lambrech Matthew

Classifications

• H01M8/0637

  Direct internal reforming at the anode of the fuel cell · CPC title

• C01B2203/043

  Regenerative adsorption process in two or more beds, one for adsorption, the other for regeneration · CPC title

• C01B3/56

  by contacting with solids; Regeneration of used solids · CPC title

• C01B2203/0827

  at least part of the fuel being a recycle stream · CPC title

• C01B2203/067

  the reforming process taking place in the fuel cell · CPC title