Fuel cells and their micro applications

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This was for my college seminar. This will tell you all about different kinds of fuel cells, their advantages, limitations and applications. Hope this was informative.

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Fuel cells and their micro applications

  1. 1. FUEL CELL AND IT’S MICRO- APPLICATIONS A Presentation By:- Mihir Kulkarni 10CH027 Manas Orpe 10CH030 Guided By:- Prof. P.N. Dange Schematics of reactant flow in a MCFC
  2. 2. WHAT IS A FUEL CELL?  It is a galvanic cell or electrochemical power source  it generates electrical energy with water and heat as its by-product  both the reactants and the products are liquids or gases
  3. 3. CONSTRUCTION & WORKING OF A FUEL CELL  Has two electrodes, anode and cathode  An electrolyte, which carries electrically charged particles from one electrode to the other  A catalyst, which speeds the reactions at the electrodes.  Overall reaction is split into two partial reactions : oxidation and reduction
  4. 4.  Process begins when Hydrogen molecules enter anode  Catalyst coating separates hydrogen’s negatively charged electrons from the positively charged protons  Electrolyte allows protons to pass through to cathode, but not electrons  Instead electrons are directed through an external circuit which creates electrical current  Oxygen molecules pass through cathode  Oxygen and protons combine with electrons after they have passed through the external circuit  Oxygen and protons combine with electrons to produce water and heat CONSTRUCTION & WORKING OF A FUEL CELL
  5. 5. TYPES OF FUEL CELL 1] Phosphoric acid fuel cell (PAFC)  Electrolyte is phosphoric acid  Efficiency is 40 to 80 percent  Operating temperature – 150 to 200oC (300 to 400o F)  Output - up to 200 kW  PAFCs tolerate a carbon monoxide concentration of about 1.5 percent
  6. 6. 2] Alkaline fuel cell (AFC)  Operate on compressed hydrogen and oxygen.  Generally use solution of potassium hydroxide (chemically KOH) in water as their electrolyte.  Efficiency is about 70 percent  Operating temperature is 150 to 200o C, (about 300 to 400o F)  Cell output ranges from 300 W to 5 kW.
  7. 7. 3] Proton-exchange-membrane fuel cell (PEMFC)  Work with a polymer electrolyte in the form of a thin, permeable sheet  Efficiency is about 40 to 50 percent  Operating temperature is about 80o C (about 175o F)  Cell outputs generally range from 50 to 250 kW.  Reactions : Anode (oxidation): H2  2H+ + 2e- Cathode (reduction): ½ O2 2H+ +2e-  H2O Overall : H2 + ½ O2  H2O
  8. 8. 4] Direct-methanol fuel cell (DMFC)  Specific content of chemical energy of about 6 kWh/kg  Operating temperatures are in the range 50-120 C,  Power outputs between 25 watts and 5 kilowatts  Reactions : Anode (oxidation) : CH3OH + 60H-  5H2O + 6e- + CO2 Cathode (reduction) : 3/2 O2 + 3H2O + 6e-  6OH- Overall : CH3OH + 3/2 O2  CO2 + 2H2O
  9. 9. 5] Molten-carbonate fuel cell (MCFC)  Use high-temperature compounds of salt (like sodium or magnesium) carbonates (chemically CO3) as the electrolyte  Efficiency ranges from 60 to 80 percent  Operating temperature is about 650o C (1,200 o F)  Output upto 2 megawatts (MW)  Reactions : Overall reaction : CO + ½O2  CO2 Oxidation reaction : CO + CO3 2-  2CO2 + 2e- Reduction reaction : ½O2 + CO2 + 2e-  CO3 2-
  10. 10. 6] Solid-oxide fuel cell (SOFC)  Use a hard, ceramic compound of metal (like calcium or zirconium) oxides (chemically, O2) as electrolyte  Efficiency is about 60 percent  Operating temperatures are about 1,000o C (about 1,800 o F)  Cells output is up to 100 kW  Reactions : Reduction reaction : ½O2 + 2H+ + 2e-  H2O Oxidation reaction : H2  2H+ + 2e- Overall reaction : H2 + ½O2  H2O
  11. 11. APPLICATIONS  Transportation  Stationary Power Stations  Telecommunications  Micro Power
  12. 12.  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.  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.  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 APPLICATIONS
  13. 13. APPLICATIONS  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.
  14. 14. ADVANTAGES  Physical Security  Reliability  Efficiency  Environmental Benefits  Battery Replacement/Alternative  Military Applications
  15. 15. ADVANTAGES  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.  Reliability : Properly configured fuel cells would result in less than one minute of down time in a six year period. U.S. businesses lose $29 Billion a year from computer failures due to power outages.  Efficiency : Because no fuel is burned to make energy, fuel cells are fundamentally more efficient than combustion systems.
  16. 16. ADVANTAGES  Environmental Benefits : Fuels cells can reduce air pollution today and offer the possibility of eliminating pollution in the future.  Battery Replacement/Alternative : Fuel Cell replacements for batteries would offer much longer operating life in a packaged of lighter or equal weight.  Military Applications : Fuel Cell technology in the military can help save lives because it reduces telltale heat and noise in combat.
  17. 17. LIMITATIONS Economic Problems :  Manufacturing cost of fuel-cell power plants is very high.  The most important components of all p.e.m.f.c. and d.m.f.c.’s is very expensive, about 700 $/m2.  Total cost of a 5-kW p.e.m.f.c power plant is be about 1200 $/kW.  In comparison cost of an analogous I.C. engine is 500-1500 $/kW.
  18. 18. LIMITATIONS The Problem Of Lifetime :  Satisfactory lifetime for smooth operation.  3 years lifetime for small plants in portable devices.  5 years for electric vehicles.  10 years for large stationary multi-megawatt power plants.  Samples of single p.e.m.f.c and stacks have been successfully operated for several thousands of hours.  But not enough data available for general use of these type of fuel cells.
  19. 19. RENEWABLE ENERGYACT : FOR INDIA'S FUTURE NEEDS  Solar water heating to be made mandatory throughout the urban areas of the country by 2012, in a phased manner.  Widespread application of co-generation concepts (heat and power) for lighting, heating and cooling
  20. 20. REFERENCES  Fuel Cells: From Fundamentals to Applications, S. Srinivasan, Springer, New York, 2006  Fuel Cell History Part 1, G. Wand, “Fuel Cell Today” June 16, 2006  Handbook of Fuel Cells: Fundamentals, Technology, Applications (four volumes), W. Vielstich, A. Lamm, and H. Gasteiger (editors), Wiley, Chichester, UK, 2003  "Confusion and Controversy: Nineteenth-Century Theories of the Voltaic Pile," pp. 133-157 in F. Bevilacqua and L. Fregonese,  Nuova Voltiana: Studies on Volta and his Times, vol. 1 (2000)

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