Hydrogen Fuel Cell Technology.ppt

1、Hydrogen Fuel Cell Technology,Will it contribute to energy independence? Stephen Cohen and Nathan Bonnett , May 18, 2007,FUEL CELL TECHNOLOGY,Technology overview Hydrogen fuel development Law, legislation, and administrative agency treatment,What is a Fuel Cell?,A Fuel Cell is an electrochemical dev

2、ice that combines hydrogen and oxygen to produce electricity, with water and heat as its by-product.,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 thre

3、e times more efficient than fuel burning.,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,How does a Fuel Cell work?,A Fuel Cell consists of two catalyst

4、coated electrodes surrounding an electrolyte One electrode is an anode and the other is a cathode,How does a Fuel Cell work?,The process begins when Hydrogen molecules enter the anode The catalyst coating separates hydrogens negatively charged electrons from the positively charged protons,How does a

5、 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,How does a Fuel Cell work?,While the electrons pass through the external circuit, oxygen molecules

6、 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,How does a Fuel Cell work?,How does a Fuel Cell work?,Individual fuel cells

7、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,Major Types of Fuel Cells,In general all fuel cells have the same basic configuration - an electrolyte and two electrodes Different types of fuel

8、 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,Major Types of Fuel Cells,Proton Exchange Membrane (PEM) This is the leading cell type for passenger car application Use

9、s 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,Major Types of Fuel

10、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 por

11、table power applications, possibly cell phones and laptops,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

12、 electrolyte and operates at about 450 degrees F One main advantage is that it can use impure hydrogen as fuel,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 m

13、ixture 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 co

14、al gasification products,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 electrolyt

15、e accelerate breakdown and corrosion inside the fuel cell,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

16、such as industrial generating stations, mainly because it requires such high temperatures,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

17、 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,Major Types of Fuel Cells,Alkaline Fuel Cell Requires pure hydrogen and oxygen beca

18、use it is very susceptible to carbon contamination Purification process of the hydrogen and oxygen is costly Susceptibility to poisoning affects cells lifetime which also affects the cost,Major Types of Fuel Cells,Regenerative Fuel Cells Currently researched by NASA This type of fuel cell involves a

19、 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,Importa

20、nce 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,Importance of Hydrogen,Hydrogen is a secondary energy resource, meaning it must

21、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,Hydrogen Production,The biggest challenge regarding hydrogen production is the co

22、st 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 Cells success in the commercial marketplace,Hydrogen Production,There are three general categories of Hydrogen production Thermal Proc

23、esses Electrolyte Processes Photolytic Processes,Hydrogen Production,Thermal Processes Natural Gas Reforming Gasification Renewable Liquid Reforming,Hydrogen Production,Natural Gas Reforming Steam Methane Reforming Hydrogen is produced from methane in natural gas using high-temperature steam Methane

24、 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,Hydrogen Production,Gasification Process in which coal or biomass is converted into gaseous co

25、mponents 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,Hydrogen Production,Renewable Liquid Reforming Biomass is processed to make renewable liquid

26、 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,Hydrogen Production,Electrolytic Processes Electrolytic processes use an electric current to split water into hydrogen and oxygen The electr

27、icity required can be generated by using renewable energy technologies such as wind, solar, geothermal and hydroelectric power,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 pos

28、sibility of hydrogen production which is cost effective and has a low environmental impact,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 o

29、nboard the automobile Funding for this technology has been pulled due to unsatisfactory efficiency,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

30、characteristics that make it difficult to store large quantities without taking up a great deal of space,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 cont

31、ent by weight (3x more than gasoline) and a very low energy content by volume (4x less than gasoline),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-we

32、ight, safe, composite materials that can help reduce the weight and volume of compressed gas storage systems,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

33、 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,How will the hydrogen be stored?,If the hydrogen is compressed and cryogenically frozen it will take up a very small amount of

34、space requiring a smaller tank, but it must be kept supercold- around -120 to -196 degrees Celsius,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 quantitie

35、s 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,How will the hydrogen be stored?,Because h

36、ydrogen 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,How will the hydrogen be stored?,Using curre

37、nt 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,How can Fuel Cell techn

38、ology be used?,Transportation Stationary Power Stations Telecommunications Micro Power,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 fu

39、el 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,How can Fuel Cell technology be used?,Stationary Power Stations Over 2,500 fuel cell systems have been ins

40、talled 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

41、by power lines,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,How can Fuel Cell technology be used?,Micro Power

42、 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,What are the benefits of Fuel Cell technology?,Physical Security Reliability Efficiency Environ

43、mental Benefits Battery Replacement/Alternative Military Applications,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 Ce

44、lls allow the country to discontinue reliance on these potential targets,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. Businesse

45、s Properly configured fuel cells would result in less than one minute of down time in a six year period,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 c

46、omes off of the fuel cell system it can be captured for beneficial purposes This is called Cogeneration,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 mo

47、tors are much more efficient and use 40-60% of the hydrogens 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,What are the benefits of Fuel Cell technology?,Efficiency Fuel Cell power gener

48、ation systems in operation today achieve 40% to 50% fuel-to-electricity efficiency In combination with a turbine, electrical efficiencies can exceed 60% When Cogeneration is used, fuel utilization can exceed 85%,What are the benefits of Fuel Cell technology?,Environmental Benefits Fuels cells can re

49、duce air pollution today and offer the possibility of eliminating pollution in the future,What are the benefits of Fuel Cell technology?,Environmental Benefits of Fuel Cell Power Generation A fuel cell power plant may create less than one ounce of pollution per 1,000 kilowatt-hours of electricity pr

50、oduced Conventional combustion generating systems produce 25 pounds of pollutants for the same electricity,What are the benefits of Fuel Cell technology?,Environmental Benefits of Fuel Cell Vehicles Fuel Cell Vehicles with hydrogen stored on-board produce ZERO POLLUTION in the conventional sense The

51、 only byproducts of these Fuel Cell vehicles are water and heat,What are the benefits of Fuel Cell technology?,Environmental Benefits of Fuel Cell Vehicles Fuel Cell Vehicles with a reformer on board to convert a liquid fuel to hydrogen would produce a small amount of pollutants, but it would be 90%

52、 less than the pollutants produced from combustion engines,What are the benefits of Fuel Cell technology?,Battery replacement/alternative Fuel Cell replacements for batteries would offer much longer operating life in a packaged of lighter or equal weight Additionally, Fuel Cell replacements would ha

53、ve an environmental advantage over batteries, since certain kinds of batteries require special disposal treatment,What are the benefits of Fuel Cell technology?,Military Applications Fuel Cell technology in the military can help save lives because it reduces telltale heat and noise in combat Handhel

54、d battlefield computers can be powered for 10 times longer with Fuel Cell power meaning soldiers could rely on their computers in the field for longer periods of time,Challenges to Fuel Cell Technology,Cost The cost of fuel cells must be reduced to compete with conventional technologies Conventional

55、 internal combustion engines cost $25-$35/kW; a fuel cell system would need to cost $30/kW to be competitive,Challenges to Fuel Cell Technology,Durability and Reliability Durability of fuel cell systems have not yet been adequately established The durability standard for automobiles is approximately

56、 150,000 miles and the ability to function under normal vehicle operating conditions For stationary systems 40,000 hours of reliable operation in a temperature range of -35 degree Celsius to 40 degrees Celsius will be required for market acceptance,Challenges to Fuel Cell Technology,System Size The

57、size and weight of current fuel cell systems must be reduced to attain market acceptance, especially with automobiles,Legal Environment,Legal Environment,Current Law Federal and State Incentives Federal and State Proposed Legislation Federal Codes and Standards Administrative Agency Treatment,Legal

58、Environment,Norms Architecture Technology Law Market,CURRENT LAWFederal,Energy Policy Act of 2005 Things to keep in mind: In many cases, the provisions require further rulemaking by the appropriate agencies (IRS, DOE, EPA, DOT, etc.) In some instances, the funds must still be appropriated through a

59、separate federal budgeting process The authorized funding listed indicates ceiling amounts that federal agencies may request for the defined activity $1.3 billion tax reductions for alternative motor vehicles and fuels (hydrogen, ethanol, methane, liquified natural gas, propane),EPAct 703: Alternative Compliance for State and Alternative Fuel Provider Fleets Requires certain fleets to acquire a percentage of AFVs each year New section provides for waiver of AFV acquisition if a petroleum reduction plan is implemented; fuel cell vehicles could help “Fleet must demonstrate an