Presentation is loading. Please wait.

Presentation is loading. Please wait.

Hydrogen Fuel Cells.

Similar presentations


Presentation on theme: "Hydrogen Fuel Cells."— Presentation transcript:

1 Hydrogen Fuel Cells

2 Hydrogen (H2) is a fuel not an energy source
Hydrogen (H2) is a fuel not 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 Production Fossil 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 Production Fossil Fuels
The downside: All of these methods release CO2

6 Production Water: 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 Production Water: 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 Production Water: 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 Production Review 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 Uses Ways 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 Uses Fuel Cell Inputs: Hydrogen Oxygen Outputs: Electricity Water Heat

14 Uses Types 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 Uses Types 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 Uses Applications of Fuel Cells

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

18 Uses Applications 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, 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 Particulate air pollution Smog Other air pollutants
htttp://airnow.gov

24 Feasibility of a U.S. Hydrogen Economy Steven Smriga Scripps 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
Consumption factor* Coal 1.3 Natural gas 1.2 Biomass 2.4 Domestic oil ?? Wind 140 Solar >740 Nuclear 3.2 *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
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 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 Energy Density General Motors Minimum Goals Compressed/Liquid Hydrogen (Currently) DOE Goal Megajoules per kilogram 6 4/10 10.8 Megajoules per liter 3/4 9.72 NOTES: Energy densities are based on total storage system volume or mass. Energy densities for compressed hydrogen are at pressures of 10,000 psi. SOURCES: DOE (2002b, 2003b)

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, SOURCE: EIA (2002)

51 Should it happen? Environment/Climate Change
Successful carbon sequestration is necessary, otherwise CO2 from petroleum will come from fossil fuel reformation to produce hydrogen Energy shifted from oil could result in massive coal mining to make up the difference Energy/National security would be addressed but not greenhouse gases Conservation, advancement of renewables, and nuclear power would be the only emission free hydrogen if CO2 sequestration is not realized

52 Should it happen? Public Health
Although fuel cells only emit water, internal combustion use produces NOx, leading to smog Unintended consequences of H2 leakage may include reduction in global oxidative capacity, increase in tropospheric ozone, and increase in stratospheric water that would exacerbate halogen induced ozone losses (Dubey, Los Alamos National Laboratory, 2003)

53 Should it happen? Energy Diversity
Quite the opposite, it could reduce us to predominately rely on coal The hydrogen economy needs support from some combination of increased renewable power, reinvigoration of nuclear power, and conservation to promote diversity

54 Should it happen? Energy Diversity
Picking winners? The track record 50s Nuclear power “too cheap to meter” Late 70s, early 80s oil price assumptions to justify large amounts of spending 90s battery powered cars Other technologies, should funding favor H2? Battery technology Biomass based fuels

55 alternatives to gasoline engines:
clean diesels gasoline-electric hybrids hydrogen internal combustion engines (H2ICE) hydrogen fuel cell vehicles (FCV)

56 Physical and regulatory infrastructure
Safety codes and standards Public awareness about fueling systems Training for fuel distribution personnel

57 Types of Fuel Cells Alkaline Fuel Cell (AFC)
Molten Carbonate Fuel Cell (MCFC) Phosphoric Acid Fuel Cell (PAFC) Proton Exchange Membrane Fuel Cell (PEMFC) Solid Oxide Fuel Cell (SOFC) Direct Methanol Fuel Cell Fuel cell types are generally characterized by electrolyte material. The electrolyte is the substance between the positive and negative terminals, serving as the bridge for the ion exchange that generates electrical current.


Download ppt "Hydrogen Fuel Cells."

Similar presentations


Ads by Google