How Fuel Cells Capture Carbon Dioxide While Making Electricity
This patent describes a system that uses special fuel cells to generate electricity and capture carbon dioxide from power plant exhaust, by recycling unused fuel back into the system.
Original patent title: “Integrated power generation and carbon capture using fuel cells”
This patent describes a system that uses special fuel cells to generate electricity and capture carbon dioxide from power plant exhaust, by recycling unused fuel back into the system. Granted to ExxonMobil Research and Engineering in 2017 with 22 claims and 3 forward citations, and it is expected to expire in 2034.
Coverage
What does this patent actually cover?
The patent details a method for simultaneously generating electricity and capturing carbon dioxide (CO2) from a combustion source, like a power plant. It uses molten carbonate fuel cells (MCFCs). First, exhaust gas containing oxygen and CO2 enters the fuel cell's cathode (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1). Inside the fuel cell, carbonate from the cathode reacts with hydrogen (H2) at the anode to produce electricity and an anode exhaust stream containing CO2 and H2 (Claim 1). A key step involves processing this anode exhaust: it's passed through a water gas shift reaction stage, then CO2 is separated out, and finally, the remaining hydrogen-rich stream is recycled back to the fuel cell anodes (Claim 1). This recycling ensures that hydrogen that wasn't used the first time gets another chance, making the process more efficient. The system is designed so that the fuel cells use at most 55% of the incoming fuel (Claim 1), leaving plenty of hydrogen to be recycled.
The gap
What does this patent NOT cover?
- Methods where the fuel cells use more than 55% of the incoming fuel (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Systems that do not recycle a portion of the CO2-depleted anode exhaust back to the fuel cell anodes (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Processes that recycle anode exhaust directly or indirectly to the cathodes (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 9).
- Carbon capture methods that do not integrate electricity generation using molten carbonate fuel cells.
- Fuel cell systems that do not include a separation stage for CO2 from the anode exhaust (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The innovation lies in the specific recycling loop of the anode exhaust, combined with a low fuel utilization rate (at most 55%). By not fully consuming the hydrogen in the first pass and then processing the anode exhaust through a water gas shift reaction and CO2 separation before recycling, the system can efficiently reuse hydrogen and reduce the overall size and cost of the CO2 capture equipment.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Integrated gasification combined cycle (IGCC) power plants with carbon capture
Natural gas power plants with post-combustion CO2 capture
Industrial facilities (e.g., cement, steel) seeking to reduce CO2 emissions
Future hydrogen-based energy systems
Why it matters
The bigger picture
This technology addresses two major industrial challenges: efficient electricity generation and reducing greenhouse gas emissions. By integrating carbon capture directly into the power generation process, it offers a way to make energy production cleaner. For industries like power generation, cement, or steel, which produce large amounts of CO2, this approach could reduce their environmental footprint while still meeting energy demands.
Filed
March 13, 2014
Granted
January 24, 2017
Market context
Who's building on this
Companies in this space
ExxonMobil Research and Engineering, the original assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, continues to be active in carbon capture and advanced energy technologies. Other major energy companies and startups focused on industrial decarbonization, such as Carbon Capture Inc., Svante, and Carbon Engineering, are also developing and deploying various carbon capture solutions, some of which may explore or utilize fuel cell-based approaches.
Market impact
This patent contributes to the growing field of carbon capture, utilization, and storage (CCUS) technologies. By proposing an integrated system for power generation and CO2 capture, it offers a pathway for industries to reduce emissions without sacrificing energy output. While not yet a widespread commercial standard, the underlying concepts are crucial for developing future low-carbon energy infrastructure and could influence the design of next-generation power plants and industrial processes.
Claim 1 — Plain English
What this patent covers
The patent details a method for simultaneously generating electricity and capturing carbon dioxide (CO2) from a combustion source, like a power plant. It uses molten carbonate fuel cells (MCFCs). First, exhaust gas containing oxygen and CO2 enters the fuel cell's cathode (Claim 1). Inside the fuel cell, carbonate from the cathode reacts with hydrogen (H2) at the anode to produce electricity and an anode exhaust stream containing CO2 and H2 (Claim 1). A key step involves processing this anode exhaust: it's passed through a water gas shift reaction stage, then CO2 is separated out, and finally, the remaining hydrogen-rich stream is recycled back to the fuel cell anodes (Claim 1). This recycling ensures that hydrogen that wasn't used the first time gets another chance, making the process more efficient. The system is designed so that the fuel cells use at most 55% of the incoming fuel (Claim 1), leaving plenty of hydrogen to be recycled.
The clever bit
The innovation lies in the specific recycling loop of the anode exhaust, combined with a low fuel utilization rate (at most 55%). By not fully consuming the hydrogen in the first pass and then processing the anode exhaust through a water gas shift reaction and CO2 separation before recycling, the system can efficiently reuse hydrogen and reduce the overall size and cost of the CO2 capture equipment.
What it does not cover
- Methods where the fuel cells use more than 55% of the incoming fuel (Claim 1).
- Systems that do not recycle a portion of the CO2-depleted anode exhaust back to the fuel cell anodes (Claim 1).
- Processes that recycle anode exhaust directly or indirectly to the cathodes (Claim 9).
- Carbon capture methods that do not integrate electricity generation using molten carbonate fuel cells.
- Fuel cell systems that do not include a separation stage for CO2 from the anode exhaust (Claim 1).
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
PatentBrief Score
Impact Score
Early stage
Citation count
12/40
Early citations
Claim breadth
15/20
Broad claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
10/20
Granted 5–10 years ago
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$117K – $374K
Midpoint $234K · 7.5 yr remaining · industry ×2.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
22 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Barckholtz, T. A., Hershkowitz, F., & Berlowitz, P. J. (2017). How Fuel Cells Capture Carbon Dioxide While Making Electricity (U.S. Patent No. 9,553,321). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/9553321/integrated-power-generation-and-carbon-capture-using-fuel-cells
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How Fuel Cells Capture Carbon Dioxide While Making Electricity cover?
This patent describes a system that uses special fuel cells to generate electricity and capture carbon dioxide from power plant exhaust, by recycling unused fuel back into the system.
Who owns patent US 9553321?
ExxonMobil Research and Engineering owns this patent, granted in 2017.
When does this patent expire?
This patent is expected to expire on March 13, 2034, when the invention enters the public domain.
What is patent US 9553321 cited by?
This patent has been cited by 3 later patents that build on its ideas.
What problem does this patent solve?
This technology addresses two major industrial challenges: efficient electricity generation and reducing greenhouse gas emissions. By integrating carbon capture directly into the power generation process, it offers a way to make energy production cleaner. For industries like power generation, cement, or steel, which produce large amounts of CO2, this approach could reduce their environmental footprint while still meeting energy demands.
What does this patent NOT cover?
Methods where the fuel cells use more than 55% of the incoming fuel (Claim 1).
Patent monitoring