fuel cell design chemical engineering senior design spring 2005 utc
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Fuel Cell Design
Chemical Engineering Senior DesignSpring 2005
UTC
Technical and EconomicAspects of a 25 kW Fuel Cell
Chris Boudreaux
Wayne Johnson
Nick Reinhardt
Technical and EconomicAspects 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
Outline
• Introduction to the project
• Process Description
• Process & Equip. Design
• Economic Analysis
Introduction
Overall Reaction
Methane + Air --> Electricity
+ Hydrogen
+ Heat + CO2
Introduction
Pressure SwingAdsorption
Fuel Cell
Reformer
Gas
Hydrogen
ElectricityAirHeat
SynGas
POR
Water
Exhaust
Fuel Cell-ChemistrySynGas
Air
O- O-
H2 H2O CO CO2
POR
O2 N2
“Air”Solid Oxide Electrolyte
is porous to O-
H2 + CO
Fuel Cell-ElectricitySynGas
Air
O- O-
H2 H2O CO CO2
POR
O2 N2
“Air”
Electrons
Load
Fuel Cell-ChallengesSynGas
Air
O- O-
H2 H2O CO CO2
POR
O2 N2
“Air”
H2 + COHot SynGas
Hot Air
Recover H2
Recover Heat
Process Description
Turn it over to Nick Reinhardt
SOFC PFD
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Fuel Preparation - 100
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Desulfurizer (DS-101)
• Removes trace amounts of Sulfur
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Fuel Humidifier (FH-102)
• 1.25 Kmol H20 per Kmol CH4
• Heat provided from combustor exhaust
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Fuel Preheater (HX-103)
• Heat provided from fuel cell POR exhaust
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
• CH4 + H2O → CO + 3H2 (85%)
• CH4 + 2H2O → CO2 + 4H2 (15%)
• Heat provided from reaction in combustor
Reformer (R-104)
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Combustor (COMB-105)
• CH4 + 2O2 → CO2 + 2H2O (100%)
• Necessary O2 provided from fuel cell air exhaust
SOFC PFD
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Air Handling and WGS - 200
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Air Compressor (COMP-224)
• Air intake for the system
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Air Preheater (HX-223)
• Heat provided by WGS exhaust
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Water Gas Shift (WGS-222)
• Consumes CO
• CO + H2O → CO2 + H2 (72%)
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Air Side Heat Recovery (HX-221)
• Heat provided by combustor exhaust
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
SOFC PFD
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Fuel Cell - 300
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Fuel Cell (FC-331)
• CO + ½ O2 → CO2 (95%)
• H2 + ½ O2 → H2O (60%)
• H to electricity = 50%
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
SOFC PFD
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Post Processing - 400
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Fuel Exhaust Condenser (HX-443)
• Condenses process water from exhaust gases
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Chiller (Ref-446)
• Provides cold water utility for HX-443
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
PSA Compressor (COMP-445)
• Provides dried, compressed exhaust gas to the PSA system
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Pressure Swing Adsorber (PSA-442)
• Purifies hydrogen
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
• Compressed hydrogen for sale
Hydrogen Compressor (COMP-447)
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Water Purifier (WP-441)
• Purifies process water
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Water Pump (P-444)
• Supplies water to fuel humidifier
Process and Equipment Design
Turn it over to Chris Boudreaux
SOFC PFD
R 104
CO
MB
105
R 104
CO
MB
105
FC 331HX 103
HX 221
WGS222
DS101
WP 441
HX 223
FH 102
PSA 442
103
101
105
104
106
110
107
108
109
102
221 226225
227
229
228
330
331
224
223
222
445a
440
447
446a
444443
441
442
P 444
COMP 224
111
445b446b
COMP 445 COMP 447HX 443
Ref 446
Heat Exchangers
• A=q/UFΔTlm
• F = 0.9• U = 30 W/m2°C
• ΔTlm = (ΔT2 – ΔT1) / [ ln(ΔT2 / ΔT1) ]
Pure Natural Gas25°C0.33 kmol/hrCH4 = 100%
Sulfur Purge25°C0.0002 kmol/hrH2S = 100%
Natural Gas Inlet25°C0.33 kmol/hrCH4 = 99.9%H2S = 0.001%
Desulfurizer
Recycled Water5°C0.37 kmol/hrH2O = 100% Cooled POC
283°C3.51 kmol/hrN2 = 86%O2 = 9%H2O = 4%CO2 =1%
Humidified NG273°C0.67 kmol/hrH2O = 56% CH4 = 44%
Pure NG25°C0.3 kmol/hrCH4 = 100%
POC Vent26°C
Fuel Humidifier
Area = 2.6 m2
q = 1.8 kW
Heated HNG840°C
Cooled POR479°C
POR850°C1.3 kmol/hrH2O = 47% H2 = 29%CO2 = 23%CO = 1%
Humidified NG273°C
Fuel Preheater
Area = 6.3 m2
q = 5.3 kW
Heated HNG840°C0.67 kmol/hrH2O = 56%CH4 = 44%
SynGas734°C1.26 kmol/hrH2 = 73%CO = 21%H2O = 3%CO2 = 2%
ReformerR-104
q = 17 kW
R-104
COMB-105
Heated HNG SynGas
POCDepleted AirPure NG
CH4 + H2O → CO + 3H2
CH4 + 2H2O → CO2 + 4H2
CombustorCOMB-105
Depleted Air850°C3.48 kmol/hrN2 = 87%O2 = 11%H2O = 2%
POC784°C3.51 kmol/hrN2 = 86%O2 = 9%H2O = 4%CO2 =1%
Pure NG25°C0.03 kmol/hrCH4 = 100%
q = -17 kW
R-104
COMB-105
CH4 + 2O2 → CO2 + 2H2O
SynGas
POC
Heated HNG
Depleted AirPure NG
Cooled POR480°C1.3 kmol/hrH2O = 47%H2 = 29%CO2 = 23%CO = 1%
WGS Exhaust480°C1.26 kmol/hrH2O = 46.5%H2 = 30%CO2 = 23.2%CO = 0.3%
Water Gas Shift Reactor
CO + H2O → CO2 + H2
POR850°C1.3 kmol/hrH2O = 47% H2 = 29%CO2 = 23%CO = 1%
Depleted Air850°C3.48 kmol/hrO2 = 11.5%
Heated Air650°C3.88 kmol/hrO2 = 21%
SynGas750°C1.26 kmol/hrH2 = 73%CO = 21%H2O = 3%CO2 = 2%
Fuel Cell
CO + ½ O2 → CO2
H2 + ½ O2 → H2O
H Exhaust25°C0.38 kmol/hrH2 = 100%
Purge25°C0.43 kmol/hrCO2 = 68%
Uncondensed Gases5°C0.68 kmol/hrH2 = 56%CO2 = 43%
Air Inlet25°C0.13 kmol/hr
Pressure Swing Adsorber
Economic Analysis
Turn it over to Wayne Johnson
Economic Components
• Capital Costs
• Operating Costs
• Income Generated
• Payback Period
• Return on Investment
Capital Cost Assumptions
• Cap Cost Program– Analysis, Synthesis, and Design of Chemical
Processes– Compares to Peters and Timmerhaus
• Stainless Steel
Equipment CostsEquipment Name Capital Cost ($)
Solid Oxide Fuel Cell $10,000PSA $10,000
Reformer/Combustor $6,300Fuel Preheater $3,400
Chiller $3,000Fuel Humidifier $2,800
Desulfurizer $1,200Water Gas Shift Reactor $1,200
Air Compressor $950Air Side Heat Recovery $670
Air Preheater $290Water Condenser $150Water Purification $100
$40,000
Lang Factor
• Fluid Processing = 4.74
• Includes:– Construction material and overhead– Labor– Contract engineering– Contingency– Site development
• $40,000 X 4.74 = $190,000
Operating Costs
Fuel $17,000Utilties $1,000
Maintenance $1,000Labor $1,000Total $20,000
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
Income
• Electricity = 25kW• Price = $0.10/kWhr
• Hydrogen = 0.38 kmol/hr
= .76 kg/hr
• Tennessee Valley industrial rate
= $11.64/kg
Electricity $22,000Hydrogen $76,000
Total $98,000
Income
Total Income vs. Expense
Costs $20,000Income $98,000Total $78,000
Income vs Expense
Investment Results
Non-discounted Payback =
2.4 Years
Return on Investment =
41%
Conclusions
• Rate of return and payback period are interesting
• Emerging technology means cost may decrease
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?