1. Fuel Cells and Fuel Cell Systems ME 1065 L. Schaefer

2. Proton Exchange Membrane Cathode: ½O 2 + 2 e - + 2 H + => H 2 O Anode: H 2 => 2 H + + 2 e - Overall: H 2 + 1/2 O 2 => H 2 O

3. Problems with PEMs/PEFCs Hydrogen Tank Rupture

4. Direct Methanol Cathode: 3/2 O 2 + 6e - + 6H + => 3 H 2 O Anode: CH 3 OH + H 2 O => 6H + + CO 2 + 6e - Overall: CH 3 OH + 3/2 O 2 => 2 H 2 O

5. DMFCs, cont.

6. Alkaline Cathode: 1/2 O 2 + H 2 O + 2e - => 2 OH - Anode: H 2 + 2(OH) - => 2H 2 O + 2 e - Overall: H 2 + 1/2 O 2 => H 2 O

7. AFCs, cont.

8. Phosphoric Acid Cathode: ½ O 2 + 2 H + + 2 e - => H 2 O Anode: H 2 => 2H + + 2e - Overall: H 2 + 1/2 O 2 => H 2 O

9. Molten Carbonate Cathode: 1/2 O 2 + CO 2 + 2 e - => (CO 3 ) = Anode: H 2 + (CO 3 ) = => H 2 O + CO 2 + 2 e - Overall: H 2 + 1/2 O 2 + CO 2 => H 2 O + CO 2

10. MCFCs, cont.

11. Solid Oxide Cathode: 1/2 O 2 + 2 e - => O = Anode: H 2 + O = => H 2 O + 2 e - Overall: H 2 + 1/2 O 2 => H 2 O

12. SOFCs, cont.

13. Basic Summary of Four Types

14. Fuel Cell Summary

15. Fuel Cell Governing Equations Heat/Mass Transfer Electrochemical Electrical Network

16. Governing Equations Heat and Mass Transfer Model Continuity, Momentum, Energy, Concentration

17. Governing Equations Heat and Mass Transfer Model, cont. Continuity, Momentum, Energy, Concentration

18. Hydrogen Fuel Cell Values Form of Water Product Temp (°C)Gibbs Free Energy of Formation (kJ/mol) Max EMF (V) Efficiency Limit (%) Liquid25-237.21.230.83 Liquid80-228.21.180.80 Gas100-225.31.170.79 Gas200-220.41.140.77 Gas400-210.31.090.74 Gas600-199.61.040.70 Gas800-188.60.980.66 Gas1000-177.40.920.62

19. Performance Curves

20. Fuel Cell Buses

21. Hybrid Power

22. Cogeneration and Cascading Energy Systems PV SOFC Turbine Chiller Boiler Electricity Chilled Water Hot Water

23. Unexpected Places!

24. Figure for Example Problem