Fuel Cell Design Chemical Engineering Senior Design Spring 2005 UTC.

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?