1. Turbines, Engines, and Fuel Cells (and also Thermoelectrics!) Technology of Energy Seminar 3 Presented by Alex Dolgonos and Jonathan E. Pfluger 1

2. Thermoelectric Materials Jonathan E. Pfluger 2

3. Why Energy? 3 1.https://www.llnl.gov/news/americans-using-more-energy- according-lawrence-livermore-analysis

4. Energy Lost is a Big Deal  2004 – U.S. DOE 1  Almost 2 Quads of energy could be recovered from industrial heat waste  50-60% of energy is rejected  55 Quads = 58 EJ = 482.6 BILLION gallons of gas  1526 gallons for each American  36.35 barrels/person at $53/barrel = $1926 4 1.Pellegrino J. et al., ACEEE Summer Study on Energy Efficiency in Industry, ACEEE/DOE (2004)

5. What about the environment? 5

6. What are Thermoelectric Generators?  Convert heat directly to electricity  Applications in:  Power generation  Solid-state refrigeration  Solid-state heating  Benefits:  Modular devices  Small form factors  No moving parts 6 Wikimedia Commons  Disadvantages:  Low efficiencies  Toxic elements  Expensive/rare elements

7. Applications 7  Power Generation  Radioisotope Thermal Generators  Waste Heat Recovery  Consumer  Geothermal  Active Cooling/Warming  Localized Cooling  CPUs  Biological Specimens

8. Extraterrestrial Applications 8 1.Google Image Search (left to right): Voyager 1, Mars Curiosity

9. Extraterrestrial Applications 9 1.http://thermoelectrics.matsci.northwestern.edu/ther moelectrics/history.html

10. Radioisotope Thermoelectric Generator (RTG) 10 1.Google Image Search (left to right): Radioisotope thermoelectric generator

11. Terrestrial Applications 11 1.Google Image Search (clockwise from top left): Thermoelectric power, Power pot, Thermoelectric car, Seiko Thermic

12. Seebeck Effect 12 Material B Material A V T T +  T

13. Operating Modes of a Thermoelectric Couple Modules T. M. Tritt, Science 31, 1276 (1996) www.marlow.com TE Couple and Module 13

14.  Figure of Merit :  High Seebeck coefficient α /S: Energy per K ( μ V/K)  High electrical conductivity σ  Low thermal conductivity κ l 14 Improving Thermoelectrics Through Phase Separation

15. 15 Balance of Parameters 1.Snyder, Nature 7, 105 (2008)

16. 16 Typical Materials 1.Snyder, Nature 7, 105 (2008)

17. Areas of Research  Bulk  Easily scalable  Methodic progress  Nano  Novel properties  Maximum manipulation of scientific theory  Organic/Oxide  Advantageous properties  Earth-abundant materials  Form factor 17

18. Recent Advancements  Northwestern – SnSe 1  ZT ~ 2.6 at 923 K  Caltech – PbTe 2  ZT ~ 1.8 for PbTe 1-x Se x 18 1)Zhao, L.D. et al., Nature 508, 373 (2014) 2)Pei, Y.Z. et al., Nature 473, 66 (2011)

19. Cost Prohibits Breadth 19 1.S. LeBlanc et al., Renewable and Sustainable Energy Reviews 32, 313 (2014)

20. Scale-Up Concerns 20

21. Outlook  Thermoelectric modules show potential  Efficiency concerns for widespread use  Materials concerns  Abundancy  Cost 21 1.Vining, C.B., Nature Materials 8, 83 (2009)

22. Questions? 22 1.Google Image Search (left to right): European Telco Orange Power Wellies, Power Felt

23. (2) Improving the ZT of PbTe 23  Na added to dope PbTe p-type  PbS nanostructures are formed in PbTe by phase separation  Nanostructures improve ZT by reducing κ lat Adding Na (1) (3) Adding PbS (4) 1)Pei, et al., Eng. Environ. Sci. (2011). 2)Leute and Volkmer, Z. Phys. Chem. (1985). 3)Girard, et al., Nano Lett. (2010). 4)Girard, et al., JACS (2011).

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25. Turbines, Engines, and Fuel Cells Alex Dolgonos 25

26. Alternator 26  Mechanical Energy  Electrical Energy  Faraday’s Law of Induction Generated Voltage # of Coils Rate of Change in Magnetic Flux

27. Carnot Engine 27

28. Carnot Engine Hot Reservoir (T = T Hot ) Magic Box Cold Reservoir (T = T Cold ) Heat In Heat Out Useful Work 28

29. Pressure-Volume Diagram 29

30. Power Cycles  Rankine Cycle (steam turbines)  Brayton Cycle (gas turbines)  Combined Cycle (both!) 30

31. Rankine Cycle (Steam) 1.Pump 2.Boiler 3.Turbine 4.Condenser 31

32. Improvements 32

33. Brayton Cycle (Gas) 33

34. Gas Turbine Schematic 34 1.http://cset.mnsu.edu/engagethermo/components_gas turbine.html

35. Regeneration 35 1.http://www.wiley.com/college/moran/CL_047146570 4_S/user/tutorials/tutorial9/tut9n_parent.html

36. Combined Cycle 36 1.http://www.pandafunds.com/assets/img/combined_cy cle_layout_diagram.jpg

37. Combined Cycle 1. Fresh air intake 2. Combustor 3. Air compressor 4. Expansion gas turbine 5. Generator 6. Turbine exhaust 7. HRSG 8. Exhaust stack 9. Superheated steam 10. Steam turbine 11. Transformer 12. Electrical grid 13. Steam condenser 14. Cooling tower 15. Boiler feed water pump 16. Boiler feed water 17. Natural gas fuel 37

38. 38 Projections  Coal: 37%  32%  Natural gas: 30%  35%

39. Jet Turbine (Turbofan) A. Low pressure spool B. High pressure spool C. Stationary components 1. Nacelle 2. Fan 3. Low pressure compressor 4. High pressure compressor 5. Combustion chamber 6. High pressure turbine 7. Low pressure turbine 8. Core nozzle 9. Fan nozzle 39

40. Rolls Royce Trent 900 40

41. Turbine Blade Technology  2500°F!!!  Nickel-based superalloys  Thermal barrier coatings  Processing improvements  Cooling 41

42. Internal Combustion Engines  Standard 4-stroke engine  Diesel engine  Surprise engine 42

43. Otto Cycle Intake Compression Power Exhaust 43

44. Partial Power Problem 44

45. Partial Power Problem 45

46. Partial Power Problem  Power is controlled by throttle opening  Lower power  Higher vacuum  Lower efficiency  Solutions  Smaller engine  Turbochargers  HEVs  Deactivation of cylinders  More gears or CVT 46

47. Running Lean 47

48. Diesel Engines  No spark required—fuel injection  No partial power problem  High T for self-ignition  More particulates  More NO X  Particulate filters  Catalytic reducers  NO X adsorbers  Low-sulfur fuel (clean diesel) 48 1.http://www.britannica.com/EBchecked/topic/290504/i nternal-combustion-engine

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50. Case Study: Wankel (Rotary) Engine  Fewer moving parts  High reliability  High power:weight  Sealing problems  Lower fuel efficiency  Lubricating oil—higher running costs 50

51. Wave Disk Engine 51  Spinning motion causes shock waves  Shock waves cause combustion  Combustion drives blades 1.http://pesn.com/2011/04/14/9501810_Wave_Disk_E ngine_Sips_Fuel/

52. Wave Disk Engine 52

53. O 2- Fuel Cells 53 O O ee ee O H H O H H H H H H ee e e CathodeElectrolyteAnode

54. Fuel Cells 54 Brett, et al., Chem. Soc. Rev., 37 (1568-1578) 2008  No combustion  Not limited to Carnot efficiency  No moving turbine engines  Maximum efficiency = 83%  Fuel cell vehicles  Tank-to-wheel efficiency = 45%  Where does the H 2 gas come from?  Methane gas  Water splitting  Plant-to-wheel efficiency  22% (compressed H 2 )  17% (liquid H 2 )

55. Solid Oxide Fuel Cells 55  High Efficiency  Solid State  No Moving Parts  High Temp (800-1000 °C)  Fuel flexibility  Expensive materials  Quicker degradation  Need materials with high conductivity at lower temp

56. 56  Solid oxide fuel cells  76 patents  Electrode and electrolyte materials  Interconnects  Device architecture  $400 million in VC funding  50% efficient  8.6 years break even period Case Study:

57. 57 Case Study:

58. Questions? 58

59. 59

60. Alternator 60  Mechanical Energy  Electrical Energy  Faraday’s Law of Induction Generated Voltage # of Coils Rate of Change in Magnetic Flux

61. Rimac Automobili: 877 hp, 115 kg 61

62. Rimac Automobili: Concept_One 62 1088 hp 0-100 km/h (0-62 mph) in 2.8 s