1. Fuel Cell Design Chemical Engineering Senior Design Spring 2005 UTC

2. Technical and Economic Aspects of a 25 kW Fuel Cell Chris Boudreaux Wayne Johnson Nick Reinhardt

3. Technical and Economic Aspects of a 25 kW Fuel Cell Investigate the design of --a 25 kW Fuel Cell --Coproduce Hydrogen --Grid parallel --Solid Oxide Electrolyte Chemical and Thermodynamic Aspects Our Competence Not Our Competence

4. Outline Introduction to the project Process Description Process & Equip. Design Economic Analysis

5. Introduction Overall Reaction Methane + Air --> Electricity + Hydrogen + Heat + CO 2

6. Introduction Pressure Swing Adsorption Fuel Cell Reformer Gas Hydrogen Electricity Air Heat SynGas POR Water Exhaust

7. Fuel Cell-Chemistry SynGas Air O-O- O-O- H2H2 H2OH2O CO CO 2 POR O 2 N 2 “Air” Solid Oxide Electrolyte is porous to O - H2H2 + CO

8. Fuel Cell-Electricity SynGas Air O-O- O-O- H2H2 H2OH2O CO CO 2 POR O 2 N 2 “Air” Electrons Load

9. Fuel Cell-Challenges SynGas Air O-O- O-O- H2H2 H2OH2O CO CO 2 POR O 2 N 2 “Air” H2H2 + CO Hot SynGas Hot Air Recover H 2 Recover Heat

10. Process Description Turn it over to Nick Reinhardt

11. SOFC PFD

12. Fuel Preparation - 100

13. Desulfurizer (DS-101) Removes trace amounts of Sulfur

14. Fuel Humidifier (FH-102) 1.25 Kmol H 2 0 per Kmol CH 4 Heat provided from combustor exhaust

15. Fuel Preheater (HX-103) Heat provided from fuel cell POR exhaust

16. CH 4 + H 2 O → CO + 3H 2 (85%) CH 4 + 2H 2 O → CO 2 + 4H 2 (15%) Heat provided from reaction in combustor Reformer (R-104)

17. Combustor (COMB-105) CH 4 + 2O 2 → CO 2 + 2H 2 O(100%) Necessary O 2 provided from fuel cell air exhaust

18. SOFC PFD

19. Air Handling and WGS - 200

20. Air Compressor (COMP-224) Air intake for the system

21. Air Preheater (HX-223) Heat provided by WGS exhaust

22. Water Gas Shift (WGS-222) Consumes CO CO + H 2 O → CO 2 + H 2 (72%)

23. Air Side Heat Recovery (HX-221) Heat provided by combustor exhaust

24. SOFC PFD

25. Fuel Cell - 300

26. Fuel Cell (FC-331) CO + ½ O 2 → CO 2 (95%) H 2 + ½ O 2 → H 2 O (60%)  H to electricity = 50%

27. SOFC PFD

28. Post Processing - 400

29. Fuel Exhaust Condenser (HX-443) Condenses process water from exhaust gases

30. Chiller (Ref-446) Provides cold water utility for HX-443

31. PSA Compressor (COMP-445) Provides dried, compressed exhaust gas to the PSA system

32. Pressure Swing Adsorber (PSA-442) Purifies hydrogen

33. Compressed hydrogen for sale Hydrogen Compressor (COMP-447)

34. Water Purifier (WP-441) Purifies process water

35. Water Pump (P-444) Supplies water to fuel humidifier

36. Process and Equipment Design Turn it over to Chris Boudreaux

37. SOFC PFD

38. Heat Exchangers A=q/UFΔT lm F = 0.9 U = 30 W/m 2 °C ΔT lm = (ΔT 2 – ΔT 1 ) / [ ln(ΔT 2 / ΔT 1 ) ]

39. Pure Natural Gas 25°C 0.33 kmol/hr CH 4 = 100% Sulfur Purge 25°C 0.0002 kmol/hr H 2 S = 100% Natural Gas Inlet 25°C 0.33 kmol/hr CH 4 = 99.9% H 2 S = 0.001% Desulfurizer

40. Recycled Water 5°C 0.37 kmol/hr H 2 O = 100% Cooled POC 283°C 3.51 kmol/hr N 2 = 86% O 2 = 9% H 2 O = 4% CO 2 =1% Humidified NG 273°C 0.67 kmol/hr H 2 O = 56% CH 4 = 44% Pure NG 25°C 0.3 kmol/hr CH 4 = 100% POC Vent 26°C Fuel Humidifier Area = 2.6 m 2 q = 1.8 kW

41. Heated HNG 840°C Cooled POR 479°C POR 850°C 1.3 kmol/hr H 2 O = 47% H 2 = 29% CO 2 = 23% CO = 1% Humidified NG 273°C Fuel Preheater Area = 6.3 m 2 q = 5.3 kW

42. Heated HNG 840°C 0.67 kmol/hr H 2 O = 56% CH 4 = 44% SynGas 734°C 1.26 kmol/hr H 2 = 73% CO = 21% H 2 O = 3% CO 2 = 2% Reformer R-104 q = 17 kW R-104 COMB-105 Heated HNG SynGas POC Depleted Air Pure NG CH 4 + H 2 O → CO + 3H 2 CH 4 + 2H 2 O → CO 2 + 4H 2

43. Combustor COMB-105 Depleted Air 850°C 3.48 kmol/hr N 2 = 87% O 2 = 11% H 2 O = 2% POC 784°C 3.51 kmol/hr N 2 = 86% O 2 = 9% H 2 O = 4% CO 2 =1% Pure NG 25°C 0.03 kmol/hr CH 4 = 100% q = -17 kW R-104 COMB-105 CH 4 + 2O 2 → CO 2 + 2H 2 O SynGas POC Heated HNG Depleted Air Pure NG

44. Cooled POR 480°C 1.3 kmol/hr H 2 O = 47% H 2 = 29% CO 2 = 23% CO = 1% WGS Exhaust 480°C 1.26 kmol/hr H 2 O = 46.5% H 2 = 30% CO 2 = 23.2% CO = 0.3% Water Gas Shift Reactor CO + H 2 O → CO 2 + H 2

45. POR 850°C 1.3 kmol/hr H 2 O = 47% H 2 = 29% CO 2 = 23% CO = 1% Depleted Air 850°C 3.48 kmol/hr O 2 = 11.5% Heated Air 650°C 3.88 kmol/hr O 2 = 21% SynGas 750°C 1.26 kmol/hr H 2 = 73% CO = 21% H 2 O = 3% CO 2 = 2% Fuel Cell CO + ½ O 2 → CO 2 H 2 + ½ O 2 → H 2 O

46. H Exhaust 25°C 0.38 kmol/hr H 2 = 100% Purge 25°C 0.43 kmol/hr CO 2 = 68% Uncondensed Gases 5°C 0.68 kmol/hr H 2 = 56% CO 2 = 43% Air Inlet 25°C 0.13 kmol/hr Pressure Swing Adsorber

47. Economic Analysis Turn it over to Wayne Johnson

48. Economic Components Capital Costs Operating Costs Income Generated Payback Period Return on Investment

49. Capital Cost Assumptions Cap Cost Program –Analysis, Synthesis, and Design of Chemical Processes –Compares to Peters and Timmerhaus Stainless Steel

50. Equipment Costs

51. Lang Factor Fluid Processing = 4.74 Includes: –Construction material and overhead –Labor –Contract engineering –Contingency –Site development $40,000 X 4.74 = $190,000

52. Operating Costs Fuel: 0.33 kmol/hr = 260,000 BTU/hr = 0.26 therms/hr Tennessee Valley industrial rate = $7.70/therm Labor included at site

53. Income Electricity = 25kW Price = $0.10/kWhr Hydrogen = 0.38 kmol/hr =.76 kg/hr Tennessee Valley industrial rate = $11.64/kg

54. Total Income vs. Expense

55. Investment Results Non-discounted Payback = 2.4 Years Return on Investment = 41%

56. Conclusions Rate of return and payback period are interesting Emerging technology means cost may decrease

57. Questions for the Board What areas require more detail? What locations should be investigated? Should we enlist an electro-chemistry team? Should we enlist an electrical engineering team?