610 likes | 1.07k Views
Fuel Cells. Technology Management Association of Chicago Arlington Heights, IL February 5, 2007. Thomas G. Benjamin J. David Carter Argonne National Laboratory. Outline. The US Energy Picture Fuel Cells- Definition and History Types of Fuel Cells PEM Fuel Cells Learning Demonstration
E N D
Fuel Cells Technology Management Association of Chicago Arlington Heights, IL February 5, 2007 Thomas G. Benjamin J. David Carter Argonne National Laboratory
Outline • The US Energy Picture • Fuel Cells- Definition and History • Types of Fuel Cells • PEM Fuel Cells • Learning Demonstration • Parting Shots • Hydrogen Storage • Resources
2004 U.S. Energy Flow in Quadrillion BTUs http://www.eia/doe/gov/emeu/aer/pdf/sec1_3.pdf
U.S. Domestic Energy Deficit (2004) Total Energy Use = 99.7 Quadrillion BTU* Total Energy Production = 70.4 Quadrillion BTU Shortfall = 29.5 QBTU Petroleum shortfall = 27.7 QBTU 2/3 of oil consumption is related to transportation *101.9 Quads used in 2005
U.S. Demand and Dependence on Foreign Oil Driven by Transportation Sector Million barrels per day Note: Domestic production includes crude oil, NG plant liquids, refinery gain, and other inputs, consistent with AER Table 5.1. Source: Transportation Energy Data Book: Edition 24, ORNL-6973, and EIA Annual Energy Outlook 2006, Feb. 2006.
Current GV Gasoline HEV Diesel HEV NG Distributed H2 FCV Distributed Wind Electro to H2 FCV Central Biomass to H2 FCV Central Wind Electro to H2 FCV Well to Pump H2 from Central Coal with Seq. to H2 FCV Pump to Wheel H2 from Central Nuclear to H2 FCV 0 1,000 2,000 3,000 4,000 5,000 6,000 Well-to-Wheel Petroleum Energy Use (Btu/mi.) Comparative Vehicle Technologies: Well-to-Wheels Petroleum Energy Use
Current GV Gasoline HEV Diesel HEV NG Distributed H2 FCV Distributed Wind Electro to H2 FCV Central Biomass to H2 FCV Central Wind Electro to H2 FCV Well to Pump H2 from Central Coal with Seq. to H2 FCV Pump to Wheel H2 from Central Nuclear to H2 FCV 0 100 200 300 400 500 Well-to-Wheel Greenhouse Gas Emissions (g/mi.) Comparative Vehicle Technologies: Well-to-Wheels Greenhouse Gas Emissions
How much power do we need? • Domestic use Computer = 150 W Refrigerator = 800 W House = 2-10 kW Small Building = 250 kW • Transportation Honda Insight = 60 kW Corvette = 300 kW Hummer = 420 kW Heavy Truck = 400-750 kW • 1 horsepower (hp) = 2500 BTU/h 3/4 kilowatt (kW)
Coal-fired Power Plant 1 GW Nuclear Plant 1 GW Hoover Dam 120 MW Largest windmills 3 MW Fuel Cell Modules 1W to 2 MW Photovoltaic Plant 4 MW Power Generation Options
Outline • The US Energy Picture • Fuel Cells- History and Definition • Types of Fuel Cells • PEM Fuel Cells • Learning Demonstration • Parting Shots • Hydrogen Storage • Resources
1839 Sir William Grove invents first fuel cell (H2SO4 + Pt Electrodes, H2 and O2) 1896 Jacques develops FC for household use 1900 Nernst first uses Zirconia as a solid electrolyte 1902 Reid describes first Alkaline FC(using KOH electrolyte) 1921 Baur constructs first Molten Carbonate FC 1959 Allis-Chalmers Manufacturing Company demonstrates a 20-horsepower FC powered tractor 1962 General Electric develops first Polymer Electrolyte FC (PEFC) Nafion first introduced – more stable PEM FC constructed 1965 Space applications: AFC used in Apollo missions, PEM used in Gemini missions 1973 Oil crisis creates new impetus for FC funding, PAFC and MCFC developed initially 1992 First commercial power plant begins operation(200kW PC25 PAFC) FC systems entering several test markets 2002
US Army MCFC, 1966 William Jacques' carbon battery, 1896 Allis-Chambers PAFC engine, 1965 Photographs from FC History William Grove's drawing of an experimental “gas battery“, 1843
Storage Cell _ Fuel Cell + _ + H2 Air H2SO4 Pb Pb H2O Storage cell: reactants self contained and electrodes consumed Lead-Acid Battery Reaction Pb + PbO2 + H2SO4 2 PbSO4 + 2 H2O Fuel cell: reactants supplied continuously and electrodes invariant Overall Fuel Cell Reactions: H2 + O2 H2O + heat + electrons A Fuel Cell is similar to a rechargeable battery Fuel Cell – Electrochemical energy conversion device in which fuel and oxidant react to generate electricity without any consumption, physically or chemically, of its electrodes or electrolyte.
OXYGEN (O2) HYDROGEN (H2) e - e - e - e - e - e - O- H+ H+ O- H+ Bipolar Plate O- H+ Cathode + Anode - Electrolyte Bipolar Plate WATER (H2O) + HEAT PEMFC: Protons formed at the anode diffuse through the electrolyte and react with electrons and oxygen at the cathode to form water and heat. ½O2 + 2H+ + 2e- H2O H2 2H+ + 2e-
Single cells are arranged into “stacks” to increase total voltage and power output Ballard PEFC Stack Cathode: O2 + 4H+ + 4e- 2H2O 1.2 V Anode: 2H2 4H+ + 4e- - 0 V Total Cell: 2H2 + O2 2H2O 1.2 V per cell Power = Volts X Amps
Electric Power Conditioner Air Fuel Exhaust Spent-Gas Burner Fuel Processor Fuel Cell Stack H2 Air Thermal & Water Management Fuel Cell System
OXYGEN OXYGEN HYDROGEN HYDROGEN e e e - - - e e e - - - e e e - - - O O O 2 2 2 H+ H+ H+ O O O 2 2 2 H+ H+ H+ O O O 2 2 2 H+ H+ H+ - - Bipolar Plate Bipolar Plate Bipolar Plate Bipolar Plate Bipolar Plate Bipolar Plate Cathode + Cathode + Electrolyte Electrolyte Anode Anode Fuel Processor BARRIERS • Fuel processor start-up/ transient operation • Durability • Cost • Emissions and environmental issues • H2 purification/CO cleanup • Fuel processor system integration and efficiency On-Board Fuel Processing Fuel Processor Power
OXYGEN OXYGEN HYDROGEN HYDROGEN e e e - - - e e e - - - e e e - - - O O O 2 2 2 H+ H+ H+ O O O 2 2 2 H+ H+ H+ O O O 2 2 2 H+ H+ H+ - - Bipolar Plate Bipolar Plate Bipolar Plate Bipolar Plate Bipolar Plate Bipolar Plate Cathode + Cathode + Electrolyte Electrolyte Anode Anode Power Fuel Cell Challenges • Durability • Cost • Electrode Performance • Water Transport Within the Stack • Thermal, Air and Water Management • Start-up Time and Energy Cost and durability present two of the more significant technical barriers to the achievement of clean, reliable, cost-effective systems.
Outline • The US Energy Picture • Fuel Cells- Definition and History • Types of Fuel Cells • PEM Fuel Cells • Learning Demonstration • Parting Shots • Hydrogen Storage • Resources
AFCs from Apollo & Spaceshuttle Spacecrafts-- NASA Alkaline Fuel Cell (AFC) Applications • Space • Transportation Features • High performance • Very sensitive to CO2 • Expensive Pt electrodes Status • “Commercially” available Equations Cathode:½O2 + H2O + 2e¯ →2OH¯ Anode: H2 + 2OH¯ → 2H2O + 2e¯
Applications Distributed power plants Combined heat and power Some buses UTC Fuel Cells 200-kW Phosphoric Acid Fuel Cell Features • Some fuel flexibility • High efficiency in cogeneration (85%) • Established service record • Platinum catalyst Status • Commercially available but expensive • Excellent reliability and availability • Millions of hours logged Equations Cathode:½O2 + 2H+ + 2e¯ → H2O Anode: H2→2H+ + 2e¯
Applications Distributed power plants Combined heat and power Fuel Cell Energy MCFC stack Molten Carbonate Fuel Cells Features • Fuel flexibility (internal reforming) • High efficiency • High temperature good for cogeneration • Base materials (nickel electrodes) • Corrosive electrolyte Status • Pre-Commercially available but expensive Equations Cathode:½O2 + CO2 + 2e¯ →CO3= Anode: H2 + CO3= → 2H2O + CO2 + 2e¯
Applications Truck APUs Distributed power plants Combined heat and power Features Slow start – subject to thermal shock High temperature High power density (watts/liter) Can use CO and light hydrocarbons directly “Cheap” components, solid electrolyte Low-yield manufacture Status Vehicle APUs Solid Oxide Fuel Cells Equations Cathode:O2 + 2e¯ →2O= Anode: H2 + O=→ H2O + 2e¯
Applications Transportation, Forklifts, etc. Power backup systems Consumer electronics with methanol fuel Features Quick start Low temperature Expensive Pt electrodes Easy manufacture Operating window limits 53-67% thermal efficiency Status Vehicle demonstrations underway Stationary/backup power “commercially” available Toyota Fuel Cell Forklift Polymer Electrolyte Fuel Cells Equations Cathode:½O2 + 2H+ + 2e¯ → H2O Anode: H2→2H+ + 2e¯
O2 out O2 in CH3OH in CH3OH out Cathode Anode Endplate Bipolar plate Direct Methanol Polymer Electrolyte FC (DMFC) Applications • Miniature applications • Consumer electronics • Battlefield Features • A subset of Polymer Electrolyte • Modified polymer electrolyte fuel cell components • Methanol crossover lowers efficiency Status • Pre-Alpha to Beta testing Equations Cathode:1.5 O2 + 6H+ + 6e¯ → 3H2O Anode: CH3OH + H2O → CO2 + 6H+ + 6e¯
Outline • The US Energy Picture • Fuel Cells- Definition and History • Types of Fuel Cells • PEM Fuel Cells • Learning Demonstration • Parting Shots • Hydrogen Storage • Resources
Membrane GDL Bipolar Plate Catalyst Half Cell Anatomy of a Proton Exchange Membrane Fuel Cell and Challenges Platinum catalyst • Electrocatalyst: High cost of platinum-based electrocatalyst • Catalyst support: Loss of surface and electrode contact of amorphous carbon under oxidative environment • Component: Gas Diffusion Layer (GDL) and bipolar plates account for 10% of stack cost Carbon support e- H+ O2 e- H2 H2 e- H2 H2O e- Electrolyte GDL GDL Cathode Anode
Significant Barriers to PEM Fuel Cell Commercialization • Durability • Membranes, catalysts, gas diffusion media, fuel cell stacks, and systems over automotive drive cycles • Cost • Materials and manufacturing costs: catalysts, membranes, bipolar plates, and gas diffusion layers • Performance • Tolerance to impurities such as carbon monoxide, sulfur compounds, and ammonia • Operation under higher temperature, low relative humidity conditions as well as sub-freezing conditions
PEM Fuel Cell System (80kWe) Development Targets for Transportation Applications
Cycling range: 0.4 to 0.9 V Particle diameters: 2 to 4 nm Some particles have a diameter of 6 nm Cycling range:0.4 to 1.2 V Particle diameters: 2 to 6 nm Some particles have a diameter of 10 nm Effect of potential cycling on Pt dissolution/agglomeration Increase in Pt particle size with cycling Particle size increases with increasing potential Increased particle size leads to decreased surface area and decreased activity Improved durability with no performance loss
H2S on H2S off Air off N2 purge H2 on Air on Increased Activity: > 10x Improved performance of Pt-alloy catalyst Mitigation of sulfur poisoning of PEMFC LANL • Anode poisoned with 1 ppm H2S • Anode is at OCV before air exposure • Air bled overnight • Cell recovered almost fully
1.00 2.5 SPTES-50 (80C) Low EW PFSA (80C) Nafion 112 (80C) for 25 micron membrane Desired Ideal 25 0.10 Conductivity (S/cm) 2 at 1 A/cm loss mV 250 0.01 0 20 40 60 80 100 Relative Humidity (%) Current Membranes Have Poor Conductivity at Low Relative Humidity • Membranes with good conductivity • (~0.1 S/cm) at • low (25-50%) RH would reduce or eliminate external • humidification requirements • Simpler system lowers cost and improves durability
Outline • The US Energy Picture • Fuel Cells- Definition and History • Types of Fuel Cells • PEM Fuel Cells • Learning Demonstration • Parting Shots • Hydrogen Storage • Resources
Integrated Transportation Fuel Cell Power System (80 kWe) Operating on Direct Hydrogen • $45/kW by 2010 • $30/kW by 2015 • 5,000 hours durability by 2010 (80OC) – 150,000 miles at 30 mph Key Transportation Fuel Cell Targets
Hydrogen refueling station, Chino, CA Photo: NREL Technology Validation Learning Demonstrations • Objectives • Validate H2 FC Vehicles and Infrastructure in Parallel • Identify Current Status of Technology and its Evolution • Assess Progress Toward Technology Readiness • Provide Feedback to H2 Research and Development
Technology Validation learning demonstrations Courtesy K. Wipke, National Renewable Energy Laboratory
LAX refueling station DTE/BP Power Park, Southfield, MI Hydrogen and gasoline station, WA DC Chino, CA Representative Hydrogen Refueling Infrastructure Courtesy K. Wipke, National Renewable Energy Laboratory
Refueling Stations Test Vehicle/Infrastructure Northern California SE Michigan Mid-Atlantic Additional Planned Stations (4) Additional Planned Stations (2) Additional Planned Stations (2) Florida Southern California Additional Planned Stations (3) Courtesy K. Wipke, National Renewable Energy Laboratory 09-22-06
First 5 quarters of project completed: • 69 vehicles now in fleet operation. An additional 62 planned for 2007-08 with 50,000-mile fuel cell systems. • 10 stations installed deployment of new H2 refueling stations for this project is about 50% complete. • No major safety problems encountered. Fuel cell durability: Maximum: 950 hours (ongoing) Average: 715 hours Range: 100 to 190 miles
Outline • The US Energy Picture • Fuel Cells- Definition and History • Types of Fuel Cells • PEM Fuel Cells • Learning Demonstration • Parting Shots (of fuel cells) • Hydrogen Storage • Resources
Stationary Fuel Cell Power Systems Fuel Cell Energy 2 MW MCFC Plug Power 7kW Residential PEFC Siemens-Westinghouse 100kW SOFC Ballard 250kW PEFC Plug Power 10 kW Residential unit UTC Fuel Cells 200kW PAFC Courtesy of Breakthrough Technologies Institute: www.fuelcells.org
Portable Fuel Cell Power Systems Fraunhofer ISE Micro-Fuel Cell Plug Power FC powered highway road sign Ballard FC powered laptop MTI Micro Fuel Cells RFID scanner Plug Power FC powered video camera Courtesy of Breakthrough Technologies Institute: www.fuelcells.org
Outline • The US Energy Picture • Fuel Cells- Definition and History • Types of Fuel Cells • PEM Fuel Cells • Learning Demonstration • Parting Shots (of fuel cells) • Hydrogen Storage • Resources
Status vs. Targets Current Status of Hydrogen Storage SystemsNo storage technology meets 2010 or 2015 targets
Outline • The US Energy Picture • Fuel Cells- Definition and History • Types of Fuel Cells • PEM Fuel Cells • Learning Demonstration • Hydrogen storage • Resources
For More Information Fact sheets available in the web site library www.hydrogen.energy.gov • Find.... • The latest news, reports & announcements • Status information about program solicitations • Fuel cell and hydrogen "basics" information
Thank You for your attention Fuel Cells Coming to an application near you