Fuel cell technology- modern green energy

This material gives a complete outlook about fuel cell types, apllication and impact on modern world.

1. FUEL CELL TECHNOLOGY PRESENTED BY : AMAL ABRAHAM R.DEENADHAYALAN

2. CONTENT Introduction Over view of fuel cell Five types of Fuel cells PEMFC – instrumentation, working Types of PEMFC Applications Advantages Disadvantages

3. Pioneer of Fuel Cell The first fuel cells were invented by “Sir William Grove”  in 1838.   The first commercial Fuel Cell was the Hydrogen – Oxygen Fuel Cell by Francis Thomas Bacon  in 1932. Sir William Grove

4. What is Fuel Cell ? Fuel cells are electrochemical cells consisting of two electrodes and an electrolyte which convert the chemical energy of chemical reaction between fuel and oxidant directly into electrical energy . FUEL OXYGEN OXYDATION ELECTRICITY

5. Components of fuel cell Electrodes Anode & Cathode - Materials which have high electron conductivity & zero proton conductivity in the form of porous catalyst (porous catalyst or carbon). Electrolyte - High proton conductivity & zero electron conductivity. Catalyst – To enhance the speed of reaction Eg : Platinum

6. Simple Working 1. The fuel (direct H2 or reformed H2) undergoes oxidation at anode and releases electrons. 2. These electrons flow through the external circuit to the cathode. 3. At cathode, oxidant (O2 from air) gets reduced. 4. The electrons produce electricity while passing through the external circuit. Electricity is generated continuously as long as fuel and the oxidant are continuously and separately supplied to the electrodes of the cell from reservoirs outside the electrochemical cell.

7. Reactions

8. Types of Fuel Cells PAFC - Phosphoric Acid Fuel Cell MCFC - Molten Carbonate Fuel Cell AFC - Alkaline Fuel Cell SOFC - Solid Oxide Fuel Cell PEMFC - Proton Exchange Membrane Fuel Cell

9. PEMFC Polymer Electrolyte Membrane Fuel Cell consists of an electrolyte membrane sandwiched between an anode (negative electrode) and a cathode (positive electrode). PEM fuel cells work with a polymer electrolyte in the form of a thin, permeable sheet and allow hydrogen protons to pass through but prohibit the passage of electrons and heavier gases.

10. INSTRUMENTATION Electrolyte Electrode Glass Diffusion Layer Current Collector

11. WORKING OF PEMFC Hydrogen fuel is processed at the anode where electrons and protons are separated. The protons pass through the membrane to the cathode while electrons travel in an external circuit, generating current. On cathode side protons and electrons combine with oxygen to produce water .

12. REACTIONS

13. TYPES OF PEMFC 1. High Temperature PEMFC 2. Direct Methanol PEMFC

14. 1. HIGH TEMPERATURE PEMFC The working temperature is increased upto 200 degree Celsius when compared to PEMFC . The electrolyte membrane differs due to decrease in proton conductivity. The membranes used are 1.Modified perfluoro sulphonated membranes, 2.Alternative sulphonated polymers and their composite 3.Acid-base polymer membranes and their composites ., Recently used membrane is Polybenzimidazole (PBI) .

15. BENEFITS OF HT-PEMFC Due to increase in temperarure the advantages are kinetics of both the electrode reactions are enhanced, tolerance of the Pt electrodes to carbon monoxide is increased, non-noble metal catalysts may be used , the cooling system for facilitating heat dissipation is simplified.

16. 2. DIRECT METHANOL PEMFC DMFC uses methanol instead of hydrogen gas. At anode : At the cathode : METHANOL ELECTRON PROTON CO2 ELECTRON HYDROGEN IONS OXYGEN WATER

17. Applications Due to light weight and high power density ,it is used in transportation. It is implemented in TATA bus STARLINE which runs in Fuel Cell Technology. Small scale power packs for remote , unattended and military application . Portable generation systems for domestic , industrial, military and maritime application .

18. Tata starbus – fuel cell technology

19. Advantages Easy construction Solid electrolyte Low working temperature Fast start-Up

20. Disadvantages Water flood management Noble metal catalyst High sensitive

21. CONCLUSION Today energy crises and environmental pollution has turned into a great problem for human . For solving these problems vast efforts to replace fossil fuels with other energy sources such as its connotation clean fuel have been taken. Fuel cells due to their particular properties are on the verge of creating a vast revolutionary change in the field of electricity. In the PEM fuel cells, from solid polymer electrolytes which have the ability to transfer of proton, has used as membrane.

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