Mench M.M. Fuel Cell Engines
Подождите немного. Документ загружается.
app JWPR067-Mench December 13, 2007 17:33 Char Count=
500 Appendix
Table A.10 Saturated Water Vapor Temperature Table
a
Temperature (
◦
C) Saturation Pressure (kPa)
−40 0.0128
−35 0.0223
−30 0.0379
−25 0.0632
−20 0.1031
−15 0.1650
−10 0.2595
−5 0.4011
0 0.6102
5 0.87
10 1.23
15 1.71
20 2.34
25 3.17
30 4.25
35 5.63
40 7.39
45 9.60
50 12.36
55 15.77
60 19.96
65 25.05
70 31.21
75 38.61
80 47.43
85 57.89
90 70.21
95 84.64
100 101.45
105 120.94
110 143.43
115 169.24
120 198.74
125 232.31
130 270.36
135 313.32
140 361.64
145 415.80
150 476.29
a
Data below 0
◦
C are based on the Goff–Gratch equation to correlate for
saturation vapor pressure over ice [1, 2]:
log
10
(10 · P
sat
) =−9.09718(273.16/T − 1) − 3.56654 log
10
(273.16/T )
+0.876793(1 − T /273.16) + log
10
(6.1071)
where T is in Kelvin and P
sat
is in kPa, and the equation is valid from −100
to 0
◦
C.
Source: Data at 0–150
◦
C from E.W. L emmon, M.O. McLinden and D.G.
Friend, “Thermophysical Properties of Fluid Systems” in NIST Chemistry
WebBook, NIST Standard Reference Database Number 69, Eds. P.J. Lin-
strom and W.G. Mallard, June 2005, National Institute of Standards and
Technology, Gaithersburg MD, 20899 (http://webbook.nist. gov).
app JWPR067-Mench December 13, 2007 17:33 Char Count=
References 501
Table A.11 Surface Tension of Water in Contact with Air
Temperature (
◦
C) Surface Tension (N/m)
0 7.56 × 10
−2
5 7.49 × 10
−2
10 7.42 × 10
−2
20 7.28 × 10
−2
30 7.12 × 10
−2
40 6.96 × 10
−2
50 6.79 × 10
−2
60 6.62 × 10
−2
70 6.44 × 10
−2
Source: International Association for the Properties of Water Steam, Viscos-
ity of Thermal Conductivity of Heavy Water Substance in Physical Chem-
istry of Aqueous Systems: Proceedings of the 12th International Conference
on the Properties of Water and Steam, Orlando, FL, 1994, al07–al38.
Other Useful Relations:
Saturation pressure of vapor over liquid water [3]:
ln P
sat
=−34.625 + 0.258T − 4.8419 × 10
−4
T
2
+ 3.3282 × 10
−7
T
3
where T is in Kelvin, and P
sat
is in Pa.
REFERENCES
1. J. A. Goff and S. Gratch, “ Low-Pressure Properties of Water from −160 to 212
◦
F,” in Transac-
tions of the American Society of Heating and Ventilating Engineers, presented at the 52nd annual
meeting of the American Society of Heating and Ventilating Engineers, New York, pp. 95–122,
1946.
2. J. A. Goff, “Saturation Pressure of Water on the New Kelvin Temperature Scale, Transactions of
the American Society of Heating and Ventilating Engineers, presented at the semi-annual meeting
of the American Society of Heating and Ventilating Engineers, Murray Bay, Que. Canada, pp.
347–354, 1957.
3. J. M. Prausnitz, R. C. Reid, and T. K. Sherwood, The Properties of Gases and Liquids, – 3,
McGraw-Hill, New York, 1997.
Index
a, see Roughness factor
Activation polarization losses, 126–132
and Butler–Volmer (BV) kinetic model,
132–154
and electrical double layer, 126–127
factors influencing, 128–129
Active humidification, 296–297
AFCs, see Alkaline fuel cells
Age of fuel cell, and activation polarization
losses, 129
Alkaline fuel cells (AFCs), 9, 10, 16, 17, 23,
410–418
advantages of, 417
conductivity of, 159
disadvantages of, 417–418
electrode materials in, 417
electrolyte system in, 413–416
gas-phase flow in, 219–220
operating conditions for, 411–413
stack configuration in, 416–417
α, see Charge transfer coefficient
α
d
, see Net drag coefficient
Aluminum, commercial production of, 30
Ammonia, hydrogen generation from,
443
Amp
`
ere, Andr
´
e-Marie, 36
Ampere (unit), 36
Ampere-hour (Ah), 37
Anions, 31
Annular mist flow regime, 240–244
Anode, 31, 32, 35
Anode kinetics, in direct methanol fuel cells,
349–350
Anode side, microporous layer on, 323
Anodic stoichiometry, 49
Apollo space program, 412
Area specific resistance (ASR), 209
Asahi Glass Co., Ltd., 196
ASR (area specific resistance), 209
Assembly, cell, 164–166
Asymmetric channel properties, 330–331
Atomic-level energy storage, 70
ATR (autothermal reformation), 441
Automotive fuel cells, 346, 453
Autothermal reformation (ATR), 441
Bacon, Sir Francis, 23, 411, 412, 417
Ballard Power Systems, Inc., 11, 20
Batteries, 30
fuel cells vs., 5–6
metal air, 418
nickel metal hydride, 434
Beginning of life (BOL) performance, 356
β, see Symmetry factor
Biofuel cells, 418
Biological hydrogen production, 442–443
Bipolar plate, 51, 294
BMW, 381
Boiling, evaporation vs., 95
BOL (beginning of life) performance, 356
Boltzmann’s constant, 85, 226
Broers, G. H. J., 392
Bruggeman correlation, 218–220
Bubble flow regime, 240, 243, 244
Bubbling pressure, 262
Bulk diffusion, 211
Burns, Larry, 191
Butler–Volmer (BV) kinetic model, 132–154
charge transfer coefficient in, 137–140
exchange current density in, 140–141
fundamental assumption of, 133
roughness factor in, 141–143
simplified equations, 141–154
symmetry factor in, 134–137
Calcium hydride, 434
Canada, fuel-cell-related patents in, 1, 2
Capillary condensation, 262–263
Capillary pressure, 251–254
Capillary transport in fuel cell diffusion media,
251–263
and capillary pressure, 251–254
Leverett approach, 254–257
microporous layer, effect of, 257–258
modified Leverett approach, 255–256
PEFC, local saturation in diffusion media of,
259–260
503
Matthew M Mench
2008
by
Iohn
Wiley
&
Sons,
Inc
Copyright
504 Index
Carbide-derived carbons (CDCs), 438
Carbon dioxide, 17, 350, 396, 413, 439
Carbon monoxide, 359, 361–362, 383–384,
406, 439
Carbon storage (of hydrogen), 437–438
Carman–Kozeny equation, 249
Carnot cycle, 29
Carroll, Eugene, 29
Catalyst layer (H
2
PEFC), 288–290
Caterpillar, 392
Cathode, 31, 32, 35
Cathode side, microporous layer on, 321–323
Cathodic stoichiometry, 49
Cations, 31
CDCs (carbide-derived carbons), 438
Cell interconnect, 51
Ceramic electrolytes, ion transport in,
202–205
Ceramic Fuel Cells Unlimited, 381
Ceria, doped, 382
Channels:
multiphase flow in, 239–244
single-phase flow in, 233–239
and consumption of reactant, 238–239
and frictional losses, 234–238
and pressure drop, 233–234
Charge, 36–37
conservation of, 33–35
and current, 37
Charge transfer coefficient (α), 137–140
Chemical hydrides, 433–434
Chemical hydrogen production, 439–441
Chemical reactions, electrochemical vs., 29–31
Chilingarian, G. V., 219
CHP systems, see Combined heat and power
systems
Cogeneration, for fuel cells, 278–279
Cold combustion, 393n.2
Colebrook, C. F., 237–238
Combined heat and power (CHP) systems, 274,
381
Compressed hydrogen, 428–431
Concentration polarization, 168–175
cause of, 168
determination of, 173–174, 466–467
and effects of change in oxygen
concentration, 170–171
and flow stoichiometry, 174–175
and mass-limiting current density, 171–173
and restriction of rate of transport to
electrode, 168–169
Condensation:
capillary, 262–263
and evaporation, 95–96
Conductance (G), 40–41, 158
Conduction, heat transfer by, 264–267
Conductivity (σ), 158
defined, 41
dependence of, on operational parameters,
41–42
and ion transport, 195
Constant-pressure specific heat (c
p
), 71
Constant-volume specific heat (c
v
), 71
Contact angle, as multiphase flow parameter,
246, 247
Contact resistance, 161–163
Control volume, thermodynamic, 6
Convection:
heat transfer by, 267–272
as mechanism of ion transport, 192–193
Coolants, 274–275, 359
Cooling:
evaporative, 95–96
liquid, 295–296
Copper sheets, production of, 31
Corrosion, separator plate, 397
Coulomb, Charles Augustin, 36
Coulomb (unit), 36–37
c
p
(constant-pressure specific heat), 71
Crossover losses, 176–181
Cryogenic liquid hydrogen, 431–433, 444–445
Current, 31, 32, 34
defined, 36
distribution of, in PEFC, 364–368, 469–470
flow of, 35–36
Current collector, 51
Current flow, and ion transport, 191
Current-interrupt method, 466
CV, see Cyclic voltammetry
c
v
(constant-volume specific heat), 71
Cyclic voltammetry (CV), 458–461
DAFCs, see Direct alcohol fuel cells
Darcy’s law, 249, 259, 333
Decal method (catalyst layer manufacturing
technique), 290
Degradation, PEFC, 356–362
chemical modes of, 359–362
and carbon monoxide poisoning, 361–362
irreversible, 360–361
reversible, 359
measurements of, 478
Index 505
physical modes of, 356–359
irreversible, 357–359
reversible, 356–357
Delphi (company), 381
DHE (dynamic hydrogen electrode), 458
Diagnostic tools, 453–479
degradation measurements, 478
distributed diagnostics, 469–474
current distribution measurement, 469–470
impedance distribution measurement,
473–474
species distribution measurement, 470–472
temperature distribution measurement, 473
electrochemical methods, 454–469
concentration polarization, determination
of, 466–467
fuel crossover, determination of,
467–469
kinetic parameters and polarization,
determination of, 454–465
ohmic parameters and polarization,
determination of, 465–466
in situ measurement and visualization,
474–478
alternative techniques, 476, 478
direct visualization techniques, 474–477
Diffusion:
bulk, 211
of hydrogen and oxygen in water vapor,
216–218
multicomponent approaches to, 215–216
surface, 233
Diffusion coefficient, 211–214
Diffusion medium (DM) layer, 7, 55, 286, 288,
290–293
Dimethoxymethane (DMM), 341–342, 355
Dimethyl ether (DME), 341–342, 352–354
Dimethyl oxalate (DMO), 341–342, 355–356
DIR (direct internal reformation), 396
Direct alcohol fuel cells (DAFCs), 17, 339–356,
438. See also Direct methanol fuel cells
(DMFCs)
dimethoxymethane/trimethoxymethane in,
355
dimethyl ether in, 352–354
dimethyl oxalate in, 355–356
drawbacks of, 340
ethanol in, 355
ethylene glycol in, 356
formaldehyde in, 352
formic acid in, 352
non-hydrogen fuels for (table), 341–342
trends in, 351
trioxane in, 355
Direct FuelCell, 392
Direct internal reformation (DIR), 396
Direct methanol fuel cells (DMFCs), 11, 13, 19,
343–351
advantages of, 344
anode kinetics in, 349–350
carbon dioxide blockage/removal in, 350
global electrochemical reactions for, 343
methanol crossover in, 348–349
safety issues, 351
technical issues with, 344
water management in, 345–348
Direct visualization tools, 474–477
Distributed diagnostics, 469–474
current distribution measurement, 469–470
impedance distribution measurement,
473–474
species distribution measurement, 470–472
temperature distribution measurement, 473
Dittus–Boelter equation, 272
DME, see Dimethyl ether
DMFCs, see Direct methanol fuel cells
DM layer, see Diffusion medium layer
DMM, see Dimethoxymethane
DMO, see Dimethyl oxalate
DOE, see U.S. Department of Energy
Doped ceria, 382
Dow, H. H., 30
Dow Chemical, 196
Drag, electro-osmotic, 312–314
Drainage, 261–262
Dryout, 357
Durability:
of molten carbonate fuel cells, 396–397
of phosphoric acid fuel cells, 408–409
of polymer electrolyte fuel cells, see
Degradation, PEFC
of solid oxide fuel cells, 390–391
Dynamic hydrogen electrode (DHE), 458
E
◦
, see Maximum expected voltage
E
◦◦
, see Thermal voltage
E. I. DuPont de Nemours and Company, 196
The Economist, 380
ECS (Electrochemical Society), 30
ECSA, see Electrochemically active surface area
Edison, Thomas, 30
Efficiency, Faradic, 48–49
506 Index
Efficiency, thermodynamic, 96–106
calculation example, 102–106
of CHP systems, 274
and heating value, 102
and LeChatelier’s principle, 101–102
and maximum electrical work for reversible
process, 96–97
and maximum expected voltage, 97
and temperature change, 100–101
and thermal voltage, 97–99
EG, see Ethylene glycol
EIS, see Electrochemical impedance
spectroscopy
Electrical double layer, 126–127
Electrical power, 42–43
Electrical shorts, polarization losses due to,
175–176
Electrochemical diagnostic methods, 454–469
concentration polarization, determination of,
466–467
fuel crossover, determination of, 467–469
gas-phase fuel crossover, 468
liquid fuel crossover, 469
kinetic parameters and polarization,
determination of, 454–465
cyclic voltammetry, 458–461
electrochemical active surface area,
462–463
electrochemical impedance spectroscopy,
454–458
Tafel plots, 463–465
ohmic parameters and polarization,
determination of, 465–466
current interrupt, 466
high-frequency resistance, 466
Electrochemical engines, fuel cells as, 3–6
Electrochemical hydrogen production, 441–442
Electrochemical impedance spectroscopy (EIS),
454–458
Electrochemically active surface area (ECSA),
288–289, 462–463
Electrochemical reactions, 29–35
chemical vs., 29–31
components of, 31–32
conservation of charge in, 33–35
Electrochemical Society (ECS), 30
Electrodes:
in alkaline fuel cells (AFCs), 417
behavior of individual, 39–40
Electrolysis (for production of hydrogen),
440–442
Electrolyte(s), 32
conductivity/resistivity values for, 159
and limitation of reactant crossover, 177–179
loss of, 360, 397, 407
transport in, see Transport in fuel cell systems
Electrolyte fracture, 357–358
Electrolyte system, in alkaline fuel cells,
413–416
Electrolytic reactions, 34, 35
Electron-based economy, 426
Electron transport, 209–210, 325
Electro-osmotic drag, 312–314
Electroplating, 30, 34
Elementary charge transfer step, 137
Energy, internal (U), 69–70
Engines, 3–4
Enthalpy (H ), 70–71. See also Enthalpy,
determination of change in
defined, 70
determination of, of a single species, 77–78
sensible, 75
total, 77
Enthalpy, determination of change in:
for nonreacting species/mixtures, 78–82
entropy, change in, 88
example, 79
ideal gas mixture, 79–82
for reacting species/mixtures, 83–91
entropy, change in, 84–88
example, 83–84
and Gibbs function, 88–91
Enthalpy of formation, 74–75
defined, 74
table, 98
Entropy:
change in:
for nonreacting species/mixtures, 88
for reacting species/mixtures, 84–88
as concept, 84–86
and Gibbs function, 88–91
for ideal gas, 86–87
for nonreacting gas mixture, 88
for nonreacting liquids/solids, 87–88
for reacting gas mixture, 88
eq (equivalent electrons), 44
Equilibrium, mechanical vs. thermodynamic, 62
Equivalent electrons (eq), 44
Equivalent weight (EW), 198
Ethanol, 341–342, 355
Ethylene glycol (EG), 341–342, 356
Evaporation, 95–96
Index 507
Evaporative cooling, 95–96
EW (equivalent weight), 198
Exchange current density (i
0
), 132, 140–141
Expected voltage, maximum, 97
F (Faraday’s constant), 44
Faraday, Michael, 45
Faraday’s constant (F), 44
Faraday’s laws, 45–48, 177, 180
Faradic efficiency, 48–49
FCE, see Fuel Cell Energy
Fick’s law, 177, 211, 231
Fick’s second law, 212
Flooding, 243, 299–301, 307, 308, 317–321,
357
Flow, calculation of maximum water uptake in
a, 94–95
Flow field design (PEFCs), 325–339
asymmetric channel properties, 330–331
considerations in, 325–326
and direction of flow, 331–332
manifold, 336–339
mesh designs, 330
patterns, 328–329
for portable and automotive applications,
334–336
and reactant bypass, 332–334
trade-offs in, 326–327
Flow work, 70
Ford, William C., Jr., 62
Formaldehyde, 341–342, 352
Formic acid, 341–342, 352
Fourier’s law of heat conduction, 264, 273
Fracture, electrolyte, 357–358
Freeze damage, 406
Frictional losses, for single-phase flow in
channels, 234–238
Froth flow regime, 240, 243
Fuel cell(s):
advantages of, 2–3
basic operating principles of, 6–7
batteries, 5–6
classification of, 9–17
cogeneration for, 278–279
development of, 23–24
as electrochemical engines, 3–6
generic, 50–56
heat engines vs., 3–5
potential applications/markets for, 17–23
socioeconomic impact of, 24–25
technical limitations of, 3
Fuel Cell Energy (FCE), 14, 20, 392
Fuel cell stack(s), 7–9
in alkaline fuel cells (AFCs), 416–417
calculations for, 47–48
heat dissipation from, 274
manifold design for, 336–339
orientation of, and flow direction, 331–332
for portable and automotive applications,
334–336
Fuel-cell vehicles, 121
Fuel crossover, experimental determination of,
467–469
gas-phase fuel crossover, 468
liquid fuel crossover, 469
Fueling, hydrogen, 445–446
Fuji Electric Company, 398
Fuller, T. F., 313
G, see Conductance; Gibbs function
Galvanic reactions, 34, 35
Gas channels, multiphase flow in, 239–244
Gas diffusion layer (GDL), 7
Gaskets, degradation of, 360–361
Gas-phase fuel crossover, experimental
determination of, 468
Gas-phase mass transport, 210–233
in alkaline fuel cells, 219–220
binary gas-phase diffusion coefficients,
calculation of, 214–215
and characteristic times for gas-, liquid-, and
solid-state diffusion, 213
and diffusion in general, 210–218
hydrogen and oxygen in water vapor,
estimation of diffusivity of, 216–217
interfacial flow between phases, 228–232
mass flux across phase boundary, 229–230
PEFC, mass transfer limiting current
density for, 231–232
solid electrolyte, crossover through,
230–231
Knudsen diffusion, 223–226
liquids, diffusion through, 226–227, 321
multicomponent diffusion approaches for,
215–216
polymer electrolyte, diffusion through,
227–228
porous media, 218–223
calculation of gas-phase transport limited
current density for, 220–222
factors affecting, 218
surface diffusion, 233
508 Index
Gas-phase specific heat, 71–73
GDL (gas diffusion layer), 7
Gemini space program, 23, 412
General Electric, 23
General Motors, 191, 413
Georgetown University, 11, 399
Gibbs function (G) (Gibbs free energy), 88–91,
96–97
Global hydrogen–oxygen redox reaction, 32–33
Grotthuss mechanism, 198
Grove, Sir William, 23
Grubb, William, 23
H, see Enthalpy
H
2
PEFCs, see Hydrogen PEFCs
Hagen–Pouiseville flow, 237
Hall, C. M., 30
Hall–Heroult process, 30
Handheld entertainment system, 12
Heat, 4–5. See also Specific heat
generation of, 263–264
latent, 75–77
Heat engines, fuel cells vs., 3–5
Heat flux, 269, 314
Heating value, 102
Heat of formation, 74–75
Heat transport:
as PEFC design consideration, 325
single-phase, 264–275
and conduction, 264–267
and convection, 267–272
and radiation, 273–274
Henry’s law, 229–231
Heroult, P. L., 30
HFR, see High-frequency resistance
HHV, see High heating value
High-frequency resistance (HFR), 457, 465,
466
High heating value (HHV), 102–104
High-power-density (HPD) design, 387
Hindenburg disaster, 430, 431
Hitachi, 392
HOR, see Hydrogen oxidation reaction
Hoses, degradation of, 360–361
HPD (high-power-density) design, 387
Humidification (of H
2
PEFC), 295–298
active, 296–297
passive, 297–298
Humidity, relative, 92
Humidity ratio, 91
Hydraulic permeability, 312
Hydride storage, 433–437
chemical hydrides, 433–434
metal hydrides, 434–437
Hydrogen, 426–449
amount needed, calculation of, 427–428
delivery of, 443–446
and fueling, 445–446
by pipeline, 444–445
by truck, 444
diffusivity of oxygen and, in water vapor,
216–218
generation of, 438–443
alternative methods, 443
biological production, 442–443
chemical production, 439–441
electrochemical production, 441–442
and infrastructure development, 446–449
safety/environmental concerns with, 444
storage of, 426–438
calculation of amount needed, 427–428
carbon storage, 437–438
compressed gas, 428–431
cryogenic liquid, 431–433
hydride storage, 433–437
liquid fuel storage, 438
volume, calculation of, 67–69
Hydrogen air fuel cell, Nernst equation for,
107–110
Hydrogen economy, 191, 426
Hydrogen oxidation reaction (HOR), 33, 34, 463
Hydrogen PEFCs (H
2
PEFCs), 9, 11, 13, 17,
285–298
advantages of, 285
bipolar plate/flow field in, 294
catalyst layer in, 288–290
diffusion media compression in, 291–293
diffusion media in, 290–291
electro-osmotic drag in, 314
humidification of, 296–298
active, 296–297
passive, 297–298
microporous layer in, 293–294
solid polymer electrolyte in, 288
subsystems in, 295–298
technical design issues with, 285–287
Hydrogen reformation, 296
Hydrogen sulfide, 409
I
0
, see Exchange current density
Ideal gas equation of state, 64–65
IFC, see International Fuel Cells
Index 509
IHP (inner Helmholtz plane), 126
Imbibition, 261–262
Impedance distribution, measurement of,
473–474
Impurities:
and activation polarization losses, 129
ionic, 360
Independent half-cell global reaction, 39
Indirect internal reformation (IRR), 396
Ingriselli, Frank, 285
Inner Helmholtz plane (IHP), 126
In-plane design (SOFC), 388
In situ measurement and visualization, 474–478
alternative techniques, 476, 478
direct visualization techniques, 474–477
Intermec Technologies, 340
Intermolecular collisions, 211
Internal combustion engine, 4
Internal energy (U ), 69–70
International Fuel Cells (IFC), 398, 399
Ionic conductivity, 158
Ionic impurities, contamination from, 360
Ionic resistance, 158
Ion transport, 191–209
in ceramic electrolytes, 202–205
and conductivity, 195
and current flow, 191
in liquid electrolytes, 205–209
dilute electrolyte solution, 206–207
MCFC electrolyte, 207–209
mechanisms of, 191–193
convection, 192–193
mass diffusion, 191–192
migration, 193
Nernst–Planck equation governing, 193–194
in solid polymer electrolytes, 195–202
and Nafion ionic conductivity, 201–202
and water uptake, 198–201
IRR (indirect internal reformation), 396
Irrigational frost protection, 76
Ise, M., 313
Japan:
fuel-cell-related patents in, 1
phosphoric acid fuel cell development in,
398–399
solid oxide fuel cell development in, 381
Joule, 37
Keith, David, 426
Ketelaar, J. A. A., 392
Kia Motor Company, 21
Kinetic energy, translational, 69
Kn (Knudsen number), 224
Knudsen diffusion, 223–226, 233
Knudsen number (Kn), 224
Kordesch, K., 21, 413
Kreuer, K. D., 313
λ, see Water uptake
Langmuir model of kinetics, 155–157
Latent heat, 75–77
defined, 75
of vaporization, 76–77
LeChatelier’s principle, 101–102
Leverett function, 254–257
LHV, see Low heating value
Lilliputian Systems, 381
Liquids, gas-phase diffusion through, 226–227,
321
Liquid cooling, 295–296
Liquid electrolytes, ion transport in, 205–209
Liquid fuel crossover, experimental
determination of, 469
Liquid fuel storage (of hydrogen), 438
Liquid hydrogen, 431–433
Liquid-phase specific heat, 74
Lithium aluminum hydride, 434
Longevity of fuel-cell systems, U.S. Department
of Energy goals for, 286
Los Alamos National Laboratory, 23
Low heating value (LHV), 102–104
Magnesium hydride, 434
Magnetic resonance imaging (MRI), 476
Manifold flow, stack, 336–339
Marubeni, 392
Mass diffusion, as mechanism of ion transport,
191–192
Mass transport, gas-phase, see Gas-phase mass
transport
Maximum expected voltage (reversible voltage)
(E
◦
), 97, 106–114
MCFCs, see Molten carbonate fuel cells
Mechanical equilibrium, 62
Metal air batteries, 418
Metal hydrides, 434–437, 446
Metal organic frameworks (MOFs), 438
Methanol, 341–342, 351
Methanol crossover, 348–349
MFCs (microbial fuel cells), 17
Mho, 40
Microbial fuel cells (MFCs), 17
510 Index
Microporous layer (MPL), 257–258
and capillary transport, 257–258
in hydrogen PEFCs, 290, 293–294
in polymer electrolyte fuel cells (PEFCs),
321–323
Migration, as mechanism of ion transport, 193
Mitsubishi Electric Company, 398–399
Mitsubishi Heavy Industries, 381
Mobion
R
fuel cell technology, 12
Modified Leverett function, 255–256
MOFs (metal organic frameworks), 438
Molten carbonate fuel cells (MCFCs), 8–10, 14,
15, 20, 23, 381, 392–398
advantages of, 397–398
conductivity of, 159
development of, 392
disadvantages of, 398
durability of, 396–397
heat generation from, 263
internal reformation of fuel gas in, 396
ionic conductivity of, 207–209
operating conditions for, 392–396
Monolithic design (SOFC), 389
MPL, see Microporous layer
MRI (magnetic resonance imaging), 476
MTI Micro Fuel Cells, 13, 340
MTU Friedrichshafen, 392
Mud cracking, 324
Nafion, 196, 198–202, 228, 230, 311–312
NASA, 23, 412
Nernst, Walther, 381
Nernst equation, 106–114, 138
and concentration polarization, 168, 169
for hydrogen air fuel cell (example), 107–110
and species crossover losses, 176–177, 179
steps for solving problems using, 107
Nernst–Planck equation, 193–194
Nernst voltage, 106–114, 396
Net drag coefficient (α
d
), 314–315
NetGen, 381
Neutron radiography (NR), 475
Newman, J., 313
New York City, 402
NFCEP Eco Soul, 35
Nickel metal hydride batteries, 434
Nickel shorting, 397
Nonideal behavior, 64–67
NR (neutron radiography), 475
Nusselt number, 270–271, 273
Nyquist plots, 457
Ohm, Georg Simon, 42
Ohmic polarization, 157–167
calculation/estimation examples, 159–161,
163–164, 166–167
and contact resistance, 161–166
and electronic/ionic resistance, 158–161
Ohm’s law, 42–43, 158, 193, 465
OHP (outer Helmholtz plane), 126
ONSI (company), 398, 399
Open-current voltage, calculation of expected,
111–114
ORRs, see Oxidation reduction reactions
Oswald ripening, 358
Outer Helmholtz plane (OHP), 126
Oxalic acid, 341–342
Oxidation, electrochemical, 31
Oxidation reduction reactions (ORRs), 7, 17,
33, 463
Oxygen:
diffusivity of hydrogen and, in water vapor,
216–218
effects of change in concentration of,
170–171
Oxygen enhancement, effect of, 110–111
Ozone hole, 444
P, s e e Pressure; Water vapor pressure
PAFCs, see Phosphoric acid fuel cells
Partial oxidation (for hydrogen production), 441
Particle image velocimetry (PIV), 476
Particulate matter, intrusion of unwanted, 357
Passive humidification, 297–298
Patents, fuel-cell-related, 1, 2
PDA/smart phone, 12
PEFCs, see Polymer electrolyte fuel cells
Peltier heating, 264
PEM fuel cells, 9. See also Polymer electrolyte
fuel cells (PEFCs)
Performance characterization of fuel cell
systems, via polarization curve, see
Polarization curve
Permeability:
hydraulic, 312
as multiphase flow parameter, 248–250
Petroleum, as fuel source, 24–25
Phosphoric acid fuel cells (PAFCs), 9, 10, 15,
16, 23, 380, 398–410
advantages of, 406–407, 409
conductivity of, 159
configurations of, 403–407
development of, 398–402