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Hydrogen Fuel Cells

Hydrogen Fuel Cells. Hydrogen (H 2 ) is a fuel not an energy source. It is the most abundant element but must be removed from larger molecules like water or petroleum. Production. Hydrogen can be produced from Fossil Fuels (currently 90% of 42 mtons/yr) Water. Production Fossil Fuels.

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Hydrogen Fuel Cells

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  1. Hydrogen Fuel Cells

  2. Hydrogen (H2) is a fuelnot an energy source.It is the most abundant element but must be removed from larger molecules like water or petroleum.

  3. Production Hydrogen can be produced from Fossil Fuels (currently 90% of 42 mtons/yr) Water

  4. ProductionFossil Fuels • Coal • converted to mixture of hydrogen (50%), methane (35%), and carbon monoxide (8%) • Steam Reforming Methane (SRM) • Most efficient, widely used, and cheapest • Partial Oxidation • Range of feed stocks, 75% SRM • Directly cracking Methane or other hydrocarbons

  5. ProductionFossil Fuels The downside: All of these methods release CO2

  6. ProductionWater: Electrolysis • Electricity + H2O → H2 + O + H2O (steam) • Large-scale units using alkaline electrolyte can run at 70–75% efficiency (EE - H2 ) • Smaller systems with polymer electrolytes reach 80–85% efficiency (EE - H2 ) • Steam electrolyzers in development may be able to reach 90% efficiency (EE - H2 )

  7. ProductionWater: Electrolysis When using electricity generated from thermal power stations the overall efficiency of converting fossil fuel to hydrogen via electrolysis would, typically, be only about 30%. (Rand, Dell, 2005) CO2 is released at the power plant

  8. ProductionWater: Direct Methods • Thermochemical • Could utilize waste heat from a nuclear plant • Could be achieved with solar mirrors • Photoelectrolysis – sunlight to H2 • presently only 1–2% efficiency • new technique reporting 4.5% efficiency • Biophotolysis – algae to H2

  9. ProductionReview Congressional Research Service

  10. Hydrogen Storage The Challenge: store large amounts of hydrogen at ambient temperature and pressure. -compressed gas tanks -cryogenic liquid hydrogen tanks -metal hydrides -chemical reactions (e.g. hydrolysis) -nanomaterials One solution: a three-dimensional lattice of tiny hollow cubes, each capable of storing eight hydrogen molecules inside Jeff Long, UC-Berkeley

  11. Hydrogen Storage J.T.S. Irvine / Journal of Power Sources 136 (2004) 203–207

  12. UsesWays to release the energy • Catalytic Combustion • High control, low temperatures possible • Heating, cooking • Direct Steam Generation • Burn it with pure oxygen to form pure steam • Peak load generation • Internal Combustion Engine • More efficient (20%) less powerful (15%) than gasoline ICE • Can be used in gas turbines and jets • Fuel Cells

  13. UsesFuel Cell Inputs:HydrogenOxygen Outputs:ElectricityWaterHeat

  14. UsesTypes of Fuel Cells • Alkaline fuel cells (AFC) • Polymer Electrolyte Membrane (PEMFC) • Phosphoric Acid fuel cells (PAFC) • Direct Methanol fuel cells (DMFC) • Molten Carbonate fuel cells (MCFC) • Solid Oxide fuel cells (SOFC)

  15. UsesTypes of Fuel Cells Overall reaction is the same H2 + ½ O2 → H2O Low temperature fuel cells AFC, PEMFC, PAFC, DMFC High temperature fuel cells MCFC, SOFC Polymer Electrolyte Membrane Vehicles Small-scale distributed power generation

  16. UsesApplications of Fuel Cells

  17. UsesApplications of Fuel Cells • Portable Devices (Direct Methanol) • Cell Phone • Laptops • Field Equipment for military • Distributed Generation • Commercial and Residential stationary • Light Duty Vehicles

  18. UsesApplications of Fuel Cells V. Ananthachar, J.J. Duffy / Solar Energy 78 (2005) 687–694

  19. Energy/National Security Total U.S. primary energy production and consumption, historical and projected, 1970 to 2025. SOURCE: EIA (2003)

  20. Energy Diversity U.S. primary energy consumption, by fuel type, historical and projected, 1970 to 2025. SOURCE: EIA (2003).

  21. Environment/Climate Change U.S. emissions of carbon dioxide, by sector and fuels, 2000. SOURCE: EIA (2002)

  22. Environment/Climate Change Estimated volume of carbon releases from passenger cars and light-duty trucks: current hydrogen production technologies (fossil fuels), 2000–2050. Source: NAS

  23. Public Health • Particulateair pollution • Smog • Other airpollutants htttp://airnow.gov

  24. Feasibility of a U.S. Hydrogen EconomySteven SmrigaScripps Institution of Oceanography

  25. Policy and Political Milestones • 2002: U.S. President Bush launches FreedomCAR, a partnership with automakers to advance research needed to increase practicality and affordability of hydrogen fuel cell vehicles • 2003: Bush State of the Union Address announces $1.2 billion hydrogen fuel initiative to develop technologies for hydrogen production and distribution infrastructure needed to power fuel cell vehicles and stationary fuel cell power sources • 2004: Governor Schwarzenegger launches California’s Hydrogen Highway Network initiative • 2005: CA Senate Bill 76: $6.5 million in funding for state-sponsored hydrogen demonstration projects through 2006

  26. Hydrogen Production using Domestic Resources Major driver: Reduction in dependence on foreign oil “The U.S. Department of Energy estimates that the hydrogen fuel initiative and FreedomCAR initiatives may reduce our demand for petroleum by over 11 million barrels per day by 2040 – approximately the amount of oil America imports today.” “America imports 55 percent of the oil it consumes; that is expected to grow to 68 percent by 2025.” -www.whitehouse.gov, January 2003

  27. Hydrogen Production using Domestic Resources *Factor by which U.S. would need to increase current consumption of this resource to produce required hydrogen equivalent Source: U.S. Dept. of Energy, H2 Posture Plan, 2004

  28. Source: National Fuel Cell Research Center, UC-Irvine

  29. Hydrogen: Toward Zero Emissions • Combined heat and power systems • Carbon capture and storage • Future energy sources: wave, geothermal, nuclear fusion • Energy storage of renewables • Modules that couple wind and solar • with hydrogen production • Capture intermittent output • Batteries may be superior for short term • applications • Contributes to distributed generation

  30. Making Fuel Cells Affordable Barriers include: durability fuel supply (some FCs require extremely pure fuel), and raw materials (e.g. platinum and other precious metals used as a catalyst)

  31. Making Fuel Cells Affordable Factors toward weakening these barriers: • Widespread fuel cell vehicle demonstration projects • California Hydrogen Highway (e.g. Chula Vista) • Canada, Japan, EU, others • Fuel cells already used in stationary power backup systems • Public-private partnerships and alliances setting goals • Solid State Energy Conversion Alliance (SECA)

  32. The overall U.S. hydrogen market is estimated at $798.1 million in 2005 and is expected to rise to $1,605.3 million in 2010. The overall European hydrogen market is estimated to be about $368 million in 2005 and is expected to grow to $740 million in 2010. Source: Fuji-Keizai USA, Inc.: 2005 Hydrogen Market, Hydrogen R&D and Commercial Implication in The U.S. and E.U.

  33. Reduction in Carbon Emissions • hydrogen fuel cell efficiency: 40-60% combustion engine efficiency: ~35% • potential for cleaner energy production Source: U.S. Dept. of Energy

  34. Transition to Hydrogen Vehicles Possible optimistic market scenario showing assumed fraction of hydrogen fuel cell and hybrid vehicles in the United States, 2000 to 2050. Sales of fuel cell light-duty vehicles and their replacement of other vehicles are shown. Source: The Hydrogen Economy: Opportunities, Costs, Barriers, and R&D Needs (2004); National Academies Press.

  35. Source: Dept. of Energy, Hydrogen Posture Plan

  36. Source: Dept. of Energy, Hydrogen Posture Plan

  37. Challenges to the Hydrogen Economy Ted Beglin Two aspects: Feasibility Misalignment with goals

  38. Can it happen?Feasibility • Chicken and the Egg • Cost of infrastructure • Competition • Storage • Public Perception • Land Usage

  39. Can it happen?Chicken and the Egg • The FCV market depends upon the availability of a hydrogen infrastructure • The hydrogen infrastructure must be promoted by hydrogen use • Neither serves any purpose without the other

  40. Can it happen?Cost of Infrastructure • Replacement value of the current energy system and related end-use equipment would be in the multi-trillion-dollar range • Both the supply side (the technologies and resources that produce hydrogen) and the demand side (the technologies and devices that convert hydrogen to services desired in the marketplace) must undergo a fundamental transformation. • In no prior case has the government attempted to promote the replacement of an entire, mature, networked energy infrastructure before market forces did the job • Market pressures from lacking petroleum supplies and/or US participation in a CO2 credit-trade market are needed to push this forward NAS, 2004

  41. Can it happen?Competition • Incumbent technologies do not stand still, but continue to improve. • The cost of the current energy infrastructure is already sunk, favoring technologies that use it. • Gasoline, Diesel, and CNG Hybrid Vehicles • Bio-diesel and Ethanol

  42. Can it happen?Competition NCEP, 2004

  43. Can it happen?Storage Goals for Hydrogen On-Board Storage to Achieve Minimum Practical Vehicle Driving Ranges

  44. Can it happen?Storage • Compressed gas tanks • Lacks energy to volume ratio • For example, for more than a 200-mile driving range, today’s natural gas vehicles usually require two 5,000 psi tanks or one 10,000 psi tank, taking up most of the trunk. (NAS) • Cryogenic liquid hydrogen tanks • About 30% of the energy in the hydrogen is wasted in the liquefaction and filling process • Emptying equipment is both complex and costly • Boil-off rate is such that the liquid can only be stored for a few days at most. (Rand, Dell 2005)

  45. Can it happen?Storage • Advanced methods may have to provide the solution, but are still in development • metal hydrides • chemical reactions (e.g. hydrolysis) • nanomaterials

  46. Can it happen?Public Perception • Public perception of safety is affected by Hindenburg Syndrome • However, it is not clear that H2 is any more dangerous than natural gas or gasoline • Irony: Because of high diffusion, it may be safer • Addison Bain, NASA veteran presented compelling evidence in 1997 that the Hindenburg’s cotton covering was coated by a substance with similarities to rocket fuel. The same ship filled with inert helium still would have burned. • Peter Hoffman, Tomorrow’s Energy, 2001

  47. Can it happen?Land Usage • New transmission lines are increasingly difficult to build, largely because of public opposition. • The transmission system is being used for purposes for which it was not originally designed, and upgrades are not keeping pace with the increasing loads on it. • Unless this situation is corrected, it may hamper the use of electrolyzers in distributed hydrogen generation facilities. • Building pipelines to carry hydrogen may encounter some of the same sitting problems.

  48. Should it happen? • Reliance on Natural Gas rather than Oil • Carbon Sequestration • Picking a winner

  49. Should it happen?Energy/National Security • We could be trading one foreign dependency for another • The initial hydrogen economy would most likely depend upon the reforming of natural gas • If natural gas is used to produce hydrogen, and if, on the margin, natural gas is imported, there would be little if any reduction in total energy imports, because natural gas for hydrogen would displace petroleum for gasoline. NAS, 2004

  50. Should it happen?Environment/Climate Change • Two sources of carbon stand out • Coal burned for electricity • Petroleum burned in transportation fuels • Hydrogen must address both to benefit the environment U.S. emissions of carbon dioxide, by sector and fuels, 2000. SOURCE: EIA (2002)

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