university of south carolina fcr laboratory dept. of chemical engineering experiment studies
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University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
EXPERIMENT STUDIES
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Gas (H 2
) out
Gas (H
2) i
n
Gas
(Air)
out
Gas (A
ir) in
End plate
Current collector
Gasket MEA Gasket
Gas diffusion layer
Graphite flow-channel block
Single PEM Fuel Cell Assembly
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Catalyst (Pt)
e-
e-
e-
Hydrogen Air (Oxygen)
- +
-
Anode
2H+ + 2e-H2
Cathode
O2+ 4H+ + 4e- 2H2O
e-
e-
e-
e-
e-
H+
H+
H+
Membrane+
Schematic of fuel cell operation
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Schematic of water transport in PEM fuel cell
Membrane
Catalyst (Pt)
H+ (H2O)n drag
H2O diffusion
Humidifier
Diffusion Layer
AirH2
H2O, H2 H2O, Air
e2H2H Pt2 OHe2O2/1H2 2
Pt2
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
50 100 150 200
Flow rate (cm3/min)
60
70
80
90
100R
ela
tive
hu
mid
ity (
%)
Humidification 70 oC
Humidification 80 oC
Humidification 90 oC
Anode
200 300 400 500
Flow rate (cm3/min)
80
82
84
86
88
90
92
94
96
98
100
Re
lativ
e h
um
idity
(%
)
Cathode
Humidification 90 oC
Humidification 80 oC
Humidification 70 oC
Anode & Cathode inlet humidity data
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Dry gas
Humid gas
DI water
Schematic of the humidity chamber
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
PEM Fuel Cells Test station and data acquisition
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Actual Serpentine Flow Field
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
3 way valve Hydrogen
Reformate
Mass Flow Controller
Heater
3 way valve
Bypass
Anode Gas In
Humidity Bottle
Mass Flow Controller
Heater
Bypass
Cathode Gas In
Humidity Bottle
Oxygen
Air
Thermocouple Controller
Heater
Cathode Gas Out
Anode Gas Out
PressureGauge
Back PressureRegulator
Thermocouple Controller
Thermocouple Controller
Fuel Cell
Cathode Vent
Anode Vent
Fuel Cell Test Station
Flow Diagram
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Schematic of water collection set up
Ice bath
Balance
ThermocoupleThermocouple
Humidifier Fuel Cell Tester
BeakerBeaker
Vent
Balance
Fuel Cell
Vent
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0 1 2 3 4 5 6 7 8 9 10
Current (A)
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Cel
l vol
tage
(V
)
T(A/C)=85/75 oC
T(A/C)=95/85 oC
Polarization curves for PEM fuel cell.( Tcell = 70 oC, pressure(A/C) = 2/2 atm, Low stoic.)
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0 10 20 30 40 50 60
Time (hour)
0
2
4
6
8
10
12
Cur
rent
(A
)
TA/C = 85/75 oC
TA/C = 75/65 oC
TA/C = 65/55 oC
TA/C = 95/85 oC
Humidity effects on PEM fuel cell performance (70 oC cell temperature, P(A/C): 2/2 atm, flow rate (A/C): 76/319 cm3/min
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0 10 20 30 40
Time (hr)
0
2
4
6
8
10
12
Cu
rre
nt
(A)
Tcell = 55 oC
Tcell = 75 oC
Tcell = 65 oC
Cell temperature effects on the performance at 0.6 V( T(A/C) = 75 oC/Bypass, pressure(A/C) = 1/1 atm, flow rate(A/C) = 66/277 cm3/min)
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Cell Temp.(oC)
Current density (A/cm2)
Anode Water Balance (g/hr)
Cathode Water Balance (g/hr) Overall
Water inat
75oC
Water out
Max. water out
at Cell Temp.
Cross to
Cathode
Water inw/o Hum.
Generation Water out
Max. water out
at Cell
Temp.
Cross from Anode
% errorcross-over
water
55 0.47 1.18 0.67 0.38 0.51 0.00 1.56 2.01 2.69 0.45 13
65 0.59 1.18 0.42 0.54 0.76 0.00 1.97 2.68 4.73 0.71 7.7
75 0.31* 1.18 0.31 1.58 0.87 0.00 1.04* 1.90 9.15 0.86 2.2
Water balance in PEM fuel Cell
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
T(A/C) (oC)
TCell
(oC)
Current density (A/cm2)
Flux of water
(g/s-cm2)
Mole H2O
/Moles H+
75/Bypass 55 0.47 1.44*10-5 0.16
75/Bypass 65 0.59 2.14*10-5 0.19
75/Bypass 75 0.31* 2.44*10-5 0.43*
Flux of water
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
End plate
Current collector
Gasket
MEA
Gasket
Gas diffusion layer (E-Lat)
Graphite flow-channel block
Pressure sensitive film
Bolt holes
Bolts
Schematic of PEM fuel cell with the pressure sensitive film
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Gasket Type Diffusion Layer Film Type Torque (in-lbf/bolt)
100 125 150
Incompressible (7 mils)
TORAY (8 mils) Super Low 234 psi 261 psi 302 psi
CARBEL-TORAY
(11 mils)
Low 1065 psi 1247 psi 1270 psi
E-LAT
(20 mils)
Low 1214 psi 1349 psi > 1400 psi
Pressure inside fuel cell as measured by pressure sensitive film.(1 psi = 1 lbf/in
2, 1 mil = 2.54 x10-5 m)
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
Current density (A/cm2)
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0C
ell
volta
ge
(V
)
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
Po
we
r d
en
sity
(W
/cm
2)
100 in-lb/bolt
100 in-lb/bolt
125 in-lb/bolt
125 in-lb/bolt
150 in-lb/bolt
150 in-lb/bolt
Effect of torque on the cell polarization & power density with an E-LAT (Tcell = 70 oC, T(A/C) = 85/75 oC, P(A/C) = 15/15 psig)
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1
Current density (A/cm2)
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0C
ell
volta
ge
(V
)
-0.1
-0.0
0.1
0.2
0.3
0.4
0.5
Po
we
r d
en
sity
(W
/cm
2)
100 in-lb/bolt
100 in-lb/bolt
125 in-lb/bolt
125 in-lb/bolt
150 in-lb/bolt
150 in-lb/bolt
Effect of torque on the cell polarization & power density with TORAYTM & CARBEL
(Tcell = 70 oC, T(A/C) = 85/75 oC, P(A/C) = 15/15 psig)
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2
Current density (A/cm2)
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0C
ell
volta
ge
(V)
0.0
0.1
0.2
0.3
0.4
0.5
Po
we
r de
nsi
ty (
W/c
m2)
100 in-lb/bolt
100 in-lb/bolt
125 in-lb/bolt
125 in-lb/bolt150 in-lb/bolt
150 in-lb/bolt
Effect of torque on the cell polarization & power density with a TORAYTM
(Tcell = 70 oC, T(A/C) = 85/75 oC, P(A/C) = 15/15 psig)
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
Current density (A/cm2)
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
Po
we
r d
en
sity
(W
/cm
2)
E-lat
Carbel100-TorayToray
Comparison of power densities for three diffusion layers at torque 125 in-lbf/bolt
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
Current density (A/cm2)
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Ce
ll vo
ltag
e (
V)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
Po
we
r d
en
sity
(W
/cm
2)
308 psi
T(A/C) = 75/65 oC
802 psi
T(A/C)=65/55 oC
572 psi
T(A/C) = 75/65 oC
572 psi
T(A/C) = 75/65 oC
308 psi
T(A/C) = 75/65 oC
802 psi
T(A/C)=95/85 oC
802 psi
T(A/C)=95/85 oC
802 psi
T(A/C)=65/55 oC
Effect of humidity & compression pressure on the cell polarization & power density at Tcell = 50 oC
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2
Current density (A/cm2)
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0C
ell v
olta
ge (
V)
T(A/C)=75/65 oC
T(A/C)=65/55 oC
T(A/C)=85/75 oC
T(A/C)=95/85 oC
Effect of humidity on the cell polarization forTcell = 50 oC and compression pressure 308 psi.
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Example water collection data for the anode side(Tcell = 50 oC, T(A/C) = 75/65 oC & compression pressure = 802 psi )
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Hum.temp.
(oC)
Current density (A/cm2)
Anode water balance (g/min)
Cathode water balance (g/min) Overall
accum. (g/min)
Water in
Water out
Accum. at
anode
Maximum water out at cell temp.
Water in
Gen. Water out
Accum. at
cathode
Maximum water out at cell temp.
65/55 0.89 0.0124
0.0208
-0.0084 0.0017 0.0379 0.0499 0.0773 0.0106 0.0324 0.0022
75/65 0.86 0.0227
0.0324
-0.0097 0.0017 0.0682 0.0483 0.0986 0.0179 0.0314 0.0081
85/75 0.78 0.0472
0.0573
-0.0101 0.0017 0.1152 0.0439 0.1402 0.0189 0.0294 0.0088
95/85 0.75* 0.1198
0.1674
-0.0475 0.0015 0.2474 0.0419 0.2412 0.0481 0.0275 0.0005
Water balance in PEM fuel cell(Cell voltage 0.5 V, cell temp. 50 oC, compression pressure 802 psi)
(*Performance degrading at 95/85 oC requires data to be estimated using an average current).
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Hum.temp.
(oC)
Current density (A/cm2)
Anode water balance (g/min)
Cathode water balance (g/min) Overall
accum. (g/min)
Water in
Water out
Accum. at
anode
Maximum water out at cell temp.
Water in
Gen. Water out
Accum. at
cathode
Maximum water out at cell temp.
65/55 0.87 0.0119
0.0283
-0.0164 0.0015 0.0361 0.0486 0.0568 0.0279 0.0310 0.0115
75/65 0.89 0.0223
0.0394
-0.0171 0.0014 0.0674 0.0497 0.0750 0.0422 0.0309 0.0251
85/75 0.85 0.0504
0.0602
-0.0098 0.0016 0.1242 0.0477 0.1133 0.0586 0.0310 0.0488
95/85 0.82* 0.1329
0.1765
-0.0436 0.0016 0.2743 0.0461 0.2116 0.1088 0.0303 0.0651
Water balance in PEM fuel cell(Cell voltage 0.5 V, cell temp. 50 oC, compression pressure 308 psi)
(*Performance degrading at 95/85 oC requires data to be estimated using an average current).
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
-
-+
+
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Schematic of Air Bleed System
H2 /CO/H2O (in)
H2 /CO2 /H2O (out) O2 /H2O (out)
O/H2O (in)
Check valve
Filter
Flow meter
Air
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0 200 400 600 800 1000 1200 1400 1600 1800
Current density (mA/cm2)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0C
ell
volta
ge
(V
)
CARBEL CL
w/o air bleed CARBEL CL
air bleed (5 %)
CARBEL CL
Neat H2
Single Side ELAT
Neat H2
Single Side ELAT
w/o air bleedSingle Side ELAT
air bleed (5 %)
Performance comparison between CARBEL CLTM and Single Side ELATTM GDM for 500 ppm CO.
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
Performance comparison between CARBEL CLTM and Single Side ELATTM GDM for 3000 ppm CO.
0 200 400 600 800 1000 1200 1400 1600 1800
Current density (mA/cm2)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0C
ell
volta
ge
(V
)
CARBEL CL
w/o air bleed CARBEL CL
air bleed (15 %)
CARBEL CL
Neat H2
SSE
Neat H2
SSE
w/o air bleed
SSE
air bleed (15 %)
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
101 102 103 1042 3 4 5 6 7 8 2 3 4 5 6 7 8 2 3 4 5 6 7 8
Current density (mA/cm2)
0.0
0.1
0.2
0.3
0.4
0.5
An
od
e O
verv
olta
ge
(E
H2 -
EH
2/C
O)
(dashed lines) 3000 ppm CO/H2; (solid lines) 500 ppm CO/H2;
(■) SSE w/ air bleed; (□) SSE w/o air bleed; (●) CARBEL CL w/ air bleed; (○) CARBEL CL w/o air bleed.
Anode overpotentials (calculated by difference) due to CO poisoning for CARBEL CLTM and Single Side ELATTM GDM at different conditions
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0 1 2 3 4 5 6 7 8
Time (hr)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8C
ell v
olta
ge (
V)
Neat H2 Neat H2
500 ppm CO/H2 for 5 min.
BaseBase
-0.323
(V/min)
Base Base
0.056
-0.332 -0.417 -0.400 -0.417 -0.400
0.051 0.053 0.053 0.0560.059
Base Base50 ppm CO/H2 (Base)
Transient performance with 50 and 500 ppm CO at 600 mA/cm2 with CARBEL CL GDM.
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0 1 2 3 4 5 6 7 8
Time (hr)
0.4
0.5
0.6
0.7
0.8
0.9C
ell v
olta
ge (
V)
Neat H2 Neat H2
500 ppm CO/H2 for 5 min.
BaseBase Base BaseBase Base50 ppm CO/H2 (Base) Base
500 ppm CO/H2 for 5 min.
Air bleeding (5%)
Transient performance with 50 and 500 ppm CO at 600 mA/cm2 during air-bleed with CARBEL CL GDM.
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0 1 2 3 4 5
Time (hr)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8C
ell
volta
ge
(V
)
Neat H2 (Base) Neat H2 (Base)
3000 ppm CO/H2 for 5 min.3000 ppm CO/H2 for 5 min.
0.088
(V/min)
- 0.971
(V/min)
0.092 0.099 0.096 0.094 0.098
-1.410 -1.437-1.437-1.413 -1.437
Base Base Base Base Base
Transient performance with neat hydrogen and 3000 ppm CO at 600 mA/cm2 with CARBEL CL GDM.
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0 1 2 3 4 5
Time (hr)
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Ce
ll vo
ltag
e (
V)
Neat H2 Neat H2
3000 ppm CO/H2 for 5 min.
-0.115
(V/min)
0.341
-0.134 -0.128 -0.125 -0.134 -0.127
0.323 0.357 0.323 0.3340.358
3000 ppm CO/H2 for 5 min.
Neat H2 Neat H2 Neat H2 Neat H2 Neat H2
Air bleeding (15 %)
Transient performance with neat hydrogen and 3000 ppm CO at 600 mA/cm2 during air-bleed withCARBEL CL GDM.
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0 1 2 3 4 5 6
Time (hr)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8C
ell v
olta
ge (
V)
Neat H2 Neat H2
3000 ppm CO/H2 for 5 min.3000 ppm CO/H2 for 5 min.
-0.729
(V/min)
0.075
-0.738 -0.746 -0.742 -0.752 -0.796
0.069 0.0670.0760.073 0.070
Base50 ppm CO/H2 (Base) Base Base Base Base Base
Transient performance with 50 and 3000 ppm CO at 600 mA/cm2 with Single-Sided ELAT GDM.
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
0 1 2 3 4 5 6 7 8
Time (hr)
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Ce
ll vo
ltag
e (
V)
Neat H2 Neat H2
3000 ppm CO/H2
for 5 min.
-0.109
(V/min)
Base
0.186
-0.173 -0.174-0.171 -0.168 -0.179
0.196 0.1920.180 0.1810.188
50 ppm CO/H2 (Base) Base Base BaseBase 50 ppm CO/H2 (Base)
Air bleeding (15 %)
3000 ppm CO/H2
for 5 min.
Transient performance with 50 and 3000 ppm CO at 600 mA/cm2 during air-bleed with Single-Sided ELAT GDM.
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
-Humidification Effect: The results show how the current changed with inlet humidity & cell temperature
-Clamp Torque Effect: Optimal compression pressure obtained. This optimum was explained in terms of changes in the porosity & conductivity.
-Interaction between compression pressure & humidity: The performance at the higher compression pressure is sensitive with changing humidity condition. Water balance data show the water transports during the fuel cell operation.
-CO poisoning on the catalyst: The results show the CO effect on the performance of PEM Fuel cell.
-The experiment data provided in useful to verify mathematical model and their prediction for PEM Fuel cell performance.
University of South Carolina
FCR Laboratory Dept. of Chemical Engineering
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