1. Fuel Cell Heat REVISION LIST -- To be removed before final presentation.JMH -- 20/april/05 3:30 pm I’ve rearranged some of the nick slides -- it is more in line with the “flow” of the process. I’ve taken some things out. I’ve made the background with header & footer on all but Title slide I added the PFD repeatedly in nick’s section to “bring the viewer back home” I’ve partially covered the non-circled parts of the PFD when showing a new section I’ve enlarged all the PFD images to max I put some of your pictures here & there I’ve added the “Turn it over” introductions I’ve revised and corrected the fuel cell details

2. Fuel Cell Design ENCH 340 Spring, 2005 UTC

3. Technical and Economic Aspects of a 25 kW Fuel Cell Chris Boudreaux Jim Henry, P.E. Wayne Johnson Nick Reinhardt

4. 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

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

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

7. Introduction Pressure Swing Absorption Fuel Cell Reformer Gas Hydrogen Electricity Air Heat SynGas POC Water Exhaust

8. Fuel Cell-Chemistry SynGas Air O-O- O-O- H2H2 H2OH2O CO CO 2 POC O 2 N 2 “Air” Solid Oxide Electrolyte Is porous to O - H2H2 + CO

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

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

11. Process Description Turn it over to Nick Reinhardt

12. SOFC PFD

13. Fuel Preparation - 100

14. Desulfurizer (DS 101) 2 ppm H 2 S in natural gas feed H 2 S removed in DS- 101 with disposable carbon filters 10% of CH 4 fed to combustor 90% of CH 4 fed fuel humidifier

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

16. Fuel Preheater (HX 103) Heat provided from fuel cell exhaust

17. Reformer (R 104) Equilibrium determined to be: –85% CH 4 → CO –15% CH 4 → CO 2 CH 4 + H 2 O → CO + 3H 2 CH 4 + 2H 2 O → CO 2 + 4H 2 Heat provided from reaction in combustor

18. Combustor (COMB 105) Extent of reaction for combustion assumed to be 100% CH 4 + 2O 2 → CO 2 + 2H 2 O Necessary O 2 provided from fuel cell air exhaust

19. SOFC PFD

20. Air Handling and WGS - 200

21. Air Compressor (COMP 224) Air intake for the system 6.65 standard cubic meters per minute flow

22. Air Preheater (HX 223) Heat provided by water gas shift exhaust

23. Water Gas Shift (WGS 222) CO + H 2 O → CO 2 + H 2 Equilibrium determined to be 94%

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

25. SOFC PFD

26. Fuel Cell - 300

27. Fuel Cell (FC 331)

28. SOFC PFD

29. Post Processing

30. Fuel Exhaust Condenser (HX 443) Uses external cooling source Condenses process water from exhaust gases Condensed water flows to WP-441 Non-condensible exhaust flows to comp-445 and PSA system 99.5% of water is condensed

31. Chiller (Ref 446) Provides cold water utility for HX-443 Supply temp = 0C Return temp = 50C Rate = 1.8 gpm Cooling = 35,500 kJ/hr (9.9kW) Power = 2.4 kW to run

32. PSA Compressor (COMP 445) Provides dried, compressed exhaust gas to the PSA system. 2 stage compressor

33. Pressure Swing Adsorber (PS 442) Uses custom adsorbant to purify hydrogen 80-90% recovery possible 99.9+ purity on the product gas achievable with slight recovery cost Delivery pressure 20 bar Recovered Hydrogen =.177 kmol/hr @ 90%

34. Produced compressed hydrogen for sale Multi-stage compressor Pressure input = 2-20 bar Pressure output = 200 bar Hydrogen Compressor (COMP 447)

35. Water Purifier (WP 441) Basic cartridge filtration of incoming water (either city supply or process supply) Excess process water discharged to city sewer

36. Water Pump (P 444) Supplies water to section 100 fuel humidifier

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

38. SOFC PFD

41. Equipment Assumptions All equipment was assumed to be stainless steel

42. Heat Exchangers 10° approach temperature was used q = UAFΔT lm F = 0.9 U = 30 W/m 2 °C ΔT lm = (ΔT 2 – ΔT 1 ) / [ ln(ΔT 2 / ΔT 1 ) ]

43. Pumps and Compressors Power = mz 1 RT 1 [({P 2 /P 1 } a – 1)]/a –T 1 = inlet temp –R = Gas Constant –Z 1 = compressibility –m = molar flow rate –a = (k-1)/k –k = C p / C v

44. Other PSA, WGS, and desulfurizer have purchased internals

45. Economic Analysis Turn it over to Wayne Johnson

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

47. Capital Cost Assumptions Cap Cost Program Stainless Steel Minimum Size Basis for all components

48. Capcost Output

49. Capital Costs

50. Sizing Adjustments Equation from Text C a /C b = (A a /A b ) n C a = Cost of Desired Equipment C b = Cost of Base Equipment A a = Desired Cost Attribute A b = Base Cost Attribute n = Cost Exponent (0.6)

51. Sizing Adjustments A b = 450 kilowatts C b = $150,000 A a = 1.2 kilowattsn = 0.6 Total adjusted cost = $4,282

52. Adjusted Costs

53. Total Installation Total Equipment cost = $51,474 Lang factor = 4.74 for fluid processing plant Total Installation = $243,985

54. Operating Costs Fuel = 158,000 BTU/hr = 0.158 therms/hr Fuji Hunt price = $7.7/therm Labor = 24 hr coverage with 4 shifts Average salary = $30K Benefits = 2x salary Total = $240,000 annually Use contract labor

55. Income Electricity = 25kW Price = $0.05/kWhr Hydrogen = 0.18 kmol/hr =.35 kg/hr Fuji Hunt price = $11.64/kg

56. Total Income vs. Expense

57. Investment Results Non-discounted Payback = 7.4 Years Return on Investment = 13.5%

58. Conclusions Materials are expensive Operation is expensive Electricity costs are low Fuel cell not recommended at this time

59. Questions?

60. Alternative CH 4 + 2H 2 OCO 2 + 4H 2 Currently 0.2kmol CH 4 0.18kmol of H 2 Revenue = $35,000 in H 2 sales Potential revenue at 50% H 2 recovery = $70,000

61. Alternative Remove fuel cell Optimize reformer and WGS for H 2 generation H 2 is only product

63. Fuel Cell Heat. Objective Develop and demonstrate a 25 kW, grid parallel, solid oxide fuel cell system that coproduces hydrogen., the installation be configured to simultaneously and efficiently produce hydrogen from a commercial natural gas feedstream in addition to electricity. This ability to produce both hydrogen and electricity at the point of use provides an early and economical pathway to hydrogen production.. Ceramic processing and challenges in the design and manufacturing process of SOFCs will be addressed. The amount of hydrogen that the unit produces may be controlled by the adjusting the natural gas flow at steady power production (i.e., adjusting the fuel utilization). A nominal production rate of 25 kg of hydrogen per day falls within the expected upper and lower utilization limits for 25 kW electricity production. The system produces a hydrogen-rich exhaust stream that will be purified using a Pressure Swing Absorption (PSA) unit. The hydrogen flow and purity are interdependent. It is expected that purity >98% is achievable for flows of 2-3 kg/day. Critical impurities, such as CO and CO2 will be measured. It is not clear that this size system makes sense for commercial production. We are looking at a 25 kW module as a building block for commercial production to begin in 2006. The size of the 25 kW module is estimated to be smaller than a 5 ft cube. The cost of early commercial systems is expected to be <$10K/kW