hydrogen fuel cell technology n.
Skip this Video
Loading SlideShow in 5 Seconds..
Hydrogen Fuel Cell Technology PowerPoint Presentation
Download Presentation
Hydrogen Fuel Cell Technology

Hydrogen Fuel Cell Technology

404 Views Download Presentation
Download Presentation

Hydrogen Fuel Cell Technology

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Hydrogen Fuel Cell Technology Will it contribute to energy independence? Stephen Cohen and Nathan Bonnett, May 18, 2007

  2. FUEL CELL TECHNOLOGY • Technology overview • Hydrogen fuel development • Law, legislation, and administrative agency treatment

  3. What is a Fuel Cell? • A Fuel Cell is an electrochemical device that combines hydrogen and oxygen to produce electricity, with water and heat as its by-product.

  4. Why is Fuel Cell Technology Important? • Since conversion of the fuel to energy takes place via an electrochemical process, not combustion • It is a clean, quiet and highly efficient process- two to three times more efficient than fuel burning.

  5. How does a Fuel Cell work? • It operates similarly to a battery, but it does not run down nor does it require recharging • As long as fuel is supplied, a Fuel Cell will produce both energy and heat

  6. How does a Fuel Cell work? • A Fuel Cell consists of two catalyst coated electrodes surrounding an electrolyte • One electrode is an anode and the other is a cathode

  7. How does a Fuel Cell work? • The process begins when Hydrogen molecules enter the anode • The catalyst coating separates hydrogen’s negatively charged electrons from the positively charged protons

  8. How does a Fuel Cell work? • The electrolyte allows the protons to pass through to the cathode, but not the electrons • Instead the electrons are directed through an external circuit which creates electrical current

  9. How does a Fuel Cell work? • While the electrons pass through the external circuit, oxygen molecules pass through the cathode • There the oxygen and the protons combine with the electrons after they have passed through the external circuit • When the oxygen and the protons combine with the electrons it produces water and heat

  10. How does a Fuel Cell work?

  11. How does a Fuel Cell work? • Individual fuel cells can then be placed in a series to form a fuel cell stack • The stack can be used in a system to power a vehicle or to provide stationary power to a building

  12. Major Types of Fuel Cells • In general all fuel cells have the same basic configuration - an electrolyte and two electrodes • Different types of fuel cells are classified by the kind of electrolyte used • The type of electrolyte used determines the kind of chemical reactions that take place and the temperature range of operation

  13. Major Types of Fuel Cells • Proton Exchange Membrane (PEM) • This is the leading cell type for passenger car application • Uses a polymer membrane as the electrolyte • Operates at a relatively low temperature, about 175 degrees • Has a high power density, can vary its output quickly and is suited for applications where quick startup is required making it popular for automobiles • Sensitive to fuel impurities

  14. Major Types of Fuel Cells • Direct Methanol (a subset of PEM) • Expected efficiencies of 40% plus low operating temperatures between 120-190 degrees • Also uses a polymer membrane as the electrolyte • Different from PEM because the anode catalyst is able to draw hydrogen from methanol without a reformer • Used more for small portable power applications, possibly cell phones and laptops

  15. Major Types of Fuel Cells • Phosphoric Acid • This is the most commercially developed fuel cell • It generates electricity at more than 40% efficiency • Nearly 85% of the steam produced can be used for cogeneration • Uses liquid phosphoric acid as the electrolyte and operates at about 450 degrees F • One main advantage is that it can use impure hydrogen as fuel

  16. Major Types of Fuel Cells • Molten Carbonate • Promises high fuel-to-electricity efficiency and the ability to utilize coal based fuels • Uses an electrolyte composed of a molten carbonate salt mixture • Require carbon dioxide and oxygen to be delivered to the cathode • Operates at extremely high temperatures 1200 degrees • Primarily targeted for use as electric utility applications • Have been operated on hydrogen, carbon monoxide, natural gas, propane, landfill gas, marine diesel and simulated coal gasification products

  17. Major Types of Fuel Cells • Molten Carbonate Fuel Cell • Because of the extreme high temperatures, non-precious metals can be used as catalysts at the anode and cathode which helps reduces cost • Disadvantage is durability • The high temperature required and the corrosive electrolyte accelerate breakdown and corrosion inside the fuel cell

  18. Major Types of Fuel Cells • Solid Oxide • Uses a hard, non-porous ceramic compound as the electrolyte • Can reach 60% power-generating efficiency • Operates at extremely high temperatures 1800 degrees • Used mainly for large, high powered applications such as industrial generating stations, mainly because it requires such high temperatures

  19. Major Types of Fuel Cells • Alkaline • Used mainly by military and space programs • Can reach 70% power generating efficiency, but considered to costly for transportation applications • Used on the Apollo spacecraft to provide electricity and drinking water • Uses a solution of potassium hydroxide in water as the electrolyte and operates at 75 -160 degrees • Can use a variety of non-precious metals as catalyst at the anode and cathode

  20. Major Types of Fuel Cells • Alkaline Fuel Cell • Requires pure hydrogen and oxygen because it is very susceptible to carbon contamination • Purification process of the hydrogen and oxygen is costly • Susceptibility to poisoning affects cell’s lifetime which also affects the cost

  21. Major Types of Fuel Cells • Regenerative Fuel Cells • Currently researched by NASA • This type of fuel cell involves a closed loop form of power generation • Uses solar energy to separate water into hydrogen and oxygen • Hydrogen and oxygen are fed into the fuel cell generating electricity, heat and water • The water byproduct is then recirculated back to the solar-powered electrolyser beginning the process again

  22. Importance of Hydrogen • Fuel Cells require highly purified hydrogen as a fuel • Researchers are developing a wide range of technologies to produce hydrogen economically from a variety of resources in environmentally friendly ways

  23. Importance of Hydrogen • Hydrogen is a secondary energy resource, meaning it must be made from another fuel • Hydrogen can be produced from a wide variety of energy resources including: • Fossil fuels, such as natural gas and coal • Nuclear energy • Renewable resources, such as solar,water, wind and biomass

  24. Hydrogen Production • The biggest challenge regarding hydrogen production is the cost • Reducing the cost of hydrogen production so as to compete in the transportation sector with conventional fuels on a per-mile basis is a significant hurdle to Fuel Cell’s success in the commercial marketplace

  25. Hydrogen Production • There are three general categories of Hydrogen production • Thermal Processes • Electrolyte Processes • Photolytic Processes

  26. Hydrogen Production • Thermal Processes • Natural Gas Reforming • Gasification • Renewable Liquid Reforming

  27. Hydrogen Production • Natural Gas Reforming • Steam Methane Reforming • Hydrogen is produced from methane in natural gas using high-temperature steam • Methane reacts with the steam in presence of a catalyst to produce hydrogen • This process accounts for about 95% of the hydrogen used today in the U.S. • Partial oxidation • Produces hydrogen by burning methane in air

  28. Hydrogen Production • Gasification • Process in which coal or biomass is converted into gaseous components by applying heat under pressure and in the presence of steam • A subsequent series of chemical reactions produces a synthesis gas which reacts with steam to produce more hydrogen that can be separated

  29. Hydrogen Production • Renewable Liquid Reforming • Biomass is processed to make renewable liquid fuels, such as ethanol or bio-oil, that are then reacted with high-temperature steam to produce hydrogen • This process is very similar to reforming natural gas

  30. Hydrogen Production • Electrolytic Processes • Electrolytic processes use an electric current to split water into hydrogen and oxygen • The electricity required can be generated by using renewable energy technologies such as wind, solar, geothermal and hydroelectric power

  31. Hydrogen Production • Photolytic Processes • Uses light energy to split water into hydrogen and oxygen • These processes are in the very early stages of research but offer the possibility of hydrogen production which is cost effective and has a low environmental impact

  32. Hydrogen Production • Auto manufacturers have worked on developing technology that would allow fuel cell cars to continue using gasoline • A “reformer” on the fuel cell car would convert the gasoline to hydrogen onboard the automobile • Funding for this technology has been pulled due to unsatisfactory efficiency

  33. How will the hydrogen be stored? • Developing safe, reliable, compact and cost-effective hydrogen storage is one of the biggest challenges to widespread use of fuel cell technology • Hydrogen has physical characteristics that make it difficult to store large quantities without taking up a great deal of space

  34. How will the hydrogen be stored? • Hydrogen will need to be stored onboard vehicles, at hydrogen production sites, refueling stations and stationary power sites • Hydrogen has a very high energy content by weight (3x more than gasoline) and a very low energy content by volume (4x less than gasoline)

  35. How will the hydrogen be stored? • If the hydrogen is compressed and stored at room temperature under moderate pressure, too large a fuel tank would be required • Researchers are trying to find light-weight, safe, composite materials that can help reduce the weight and volume of compressed gas storage systems

  36. How will the hydrogen be stored? • Liquid hydrogen could be kept in a smaller tank than gaseous hydrogen, but liquefying hydrogen is complicated and not energy efficient • Liquid hydrogen is also extremely sensitive to heat and expands significantly when warmed by even a few degrees, thus the tank insulation required affects the weight and volume that can be stored

  37. How will the hydrogen be stored? • If the hydrogen is compressed and cryogenically frozen it will take up a very small amount of space requiring a smaller tank, but it must be kept supercold- around -120 to -196 degrees Celsius

  38. How will the hydrogen be stored? • Scientists are researching Materials-based storage • This involves tightly binding hydrogen atoms or molecules with other elements in a compound to store larger quantities of hydrogen in smaller volumes at low pressure near room temperature • This technology is considered very promising but additional research is needed to overcome problems dealing with capacity, cost, life cycle impacts and the uptake and release of hydrogen

  39. How will the hydrogen be stored? • Because hydrogen is thought to be an alternative fuel for automobiles, much of the research for hydrogen storage is focused on onboard vehicles • Scientists are attempting to develop technology that can rival the performance and cost of gasoline fuel storage systems

  40. How will the hydrogen be stored? • Using current storage technology, in order to place a sufficient amount of hydrogen onboard a vehicle to provide 300-mile driving range the tank would be larger that the trunk of a typical automobile • This large of a tank would add to the overall weight of the car and reduce fuel economy

  41. How can Fuel Cell technology be used? • Transportation • Stationary Power Stations • Telecommunications • Micro Power

  42. How can Fuel Cell technology be used? • Transportation • All major automakers are working to commercialize a fuel cell car • Automakers and experts speculate that a fuel cell vehicle will be commercialized by 2010 • 50 fuel cell buses are currently in use in North and South America, Europe, Asia and Australia • Trains, planes, boats, scooters, forklifts and even bicycles are utilizing fuel cell technology as well

  43. How can Fuel Cell technology be used? • Stationary Power Stations • Over 2,500 fuel cell systems have been installed all over the world in hospitals, nursing homes, hotels, office buildings, schools and utility power plants • Most of these systems are either connected to the electric grid to provide supplemental power and backup assurance or as a grid-independent generator for locations that are inaccessible by power lines

  44. How can Fuel Cell technology be used? • Telecommunications • Due to computers, the Internet and sophisticated communication networks there is a need for an incredibly reliable power source • Fuel Cells have been proven to be 99.999% reliable

  45. How can Fuel Cell technology be used? • Micro Power • Consumer electronics could gain drastically longer battery power with Fuel Cell technology • Cell phones can be powered for 30 days without recharging • Laptops can be powered for 20 hours without recharging

  46. What are the benefits of Fuel Cell technology? • Physical Security • Reliability • Efficiency • Environmental Benefits • Battery Replacement/Alternative • Military Applications

  47. What are the benefits of Fuel Cell technology? • Physical Security • Both central station power generation and long distance, high voltage power grids can be terrorist targets in an attempt to cripple our energy infrastructure • Fuel Cells allow the country to discontinue reliance on these potential targets

  48. What are the benefits of Fuel Cell technology? • Reliability • U.S. businesses lose $29 Billion a year from computer failures due to power outages • More reliable power from fuel cells would prevent loss of dollars for U.S. Businesses • Properly configured fuel cells would result in less than one minute of down time in a six year period

  49. What are the benefits of Fuel Cell technology? • Efficiency • Because no fuel is burned to make energy, fuel cells are fundamentally more efficient than combustion systems • Additionally when the heat comes off of the fuel cell system it can be captured for beneficial purposes • This is called Cogeneration

  50. What are the benefits of Fuel Cell technology? • Efficiency • The gasoline engine in a conventional car is less than 20% efficient in converting the chemical energy in gasoline into power • Fuel Cell motors are much more efficient and use 40-60% of the hydrogen’s energy • Fuel Cell cars would lead to a 50% reduction in fuel consumption • Fuel Cell vehicles can be up to 3 times more efficient than internal combustion engines