This paper presents the electricity and hydrogen co-production concept, a methodology for the study of SOFC hydrogen co-production, and simulation results that address the impact of reformer placement in the cycle on system performance. The methodology is based on detailed thermodynamic and electrochemical analyses of the systems. A comparison is made between six specific cycle configurations, which use fuel cell heat to drive hydrogen production in a reformer using both external and internal reforming options. SOFC plant performance has been evaluated on the basis of methane fuel utilization efficiency and each component of the plant has been evaluated on the basis of second law efficiency. The analyses show that in all cases the exergy losses (irreversibilities) in the combustion chamber are the most significant losses in the cycle. Furthermore, for the same power output, the internal reformation option has the higher electrical efficiency and produces more hydrogen per unit of natural gas supplied. Electrical efficiency of the proposed cycles ranges from 41 to 44%, while overall efficiency (based on combined electricity and hydrogen products) ranges from 45 to 80%. The internal reforming case (steam-to-carbon ratio of 3.0) had the highest overall and electrical efficiency (80 and 45% respectively), but lower second law efficiency (61%), indicating potential for cycle improvements.

1.
Ahmed
,
S.
, and
Krumpelt
,
M.
, 2001, “
Hydrogen from Hydrocarbon Fuels for Fuel Cells
,”
Int. J. Hydrogen Energy
0360-3199,
26
, pp.
291
301
.
2.
Ogden
,
J. M.
, 2002, “
Review of Small Stationary Reformers for Hydrogen Production
,” Technical Report No. IEA/H2/TR-02/002, International Energy Agency.
3.
Hammerli
,
M.
, 1984, “
When Will Electrolytic Hydrogen Become Competitive?
,”
Int. J. Hydrogen Energy
0360-3199,
9
(
1/2
), pp.
25
51
.
4.
Morse
,
S.
, 2004, “
Hydrogen—The Fuel of Today
,” Technical report, available at www.eng.usf.edu/rnr/ret_2004/HYDROGEN_FUEL_OF_THE_FUTURE.docwww.eng.usf.edu/rnr/ret_2004/HYDROGEN_FUEL_OF_THE_FUTURE.doc
5.
Lipman
,
T.
, 2004, “
What Will Power the Hydrogen Economy?
,” Technical Report No. UCD-ITS-RR-04-10, The Natural Resources Defense Council.
6.
Lutz
,
A. E.
,
Bradshawa
,
R. W.
,
Kellera
,
J. O.
, and
Witmerb
,
D. E.
, 2003, “
ThermodynamiC Analysis of Hydrogen Production by Steam Reforming
,”
Int. J. Hydrogen Energy
0360-3199,
28
, pp.
159
167
.
7.
Gordon
,
S.
, and
McBride
,
B. J.
, 1994, “
Computer Program for the Calculation of Complex Chemical Equilibrium Compositions with Applications: I. Analysis
,” NASA Reference Publication 1311.
8.
Hirschenhofer
,
J. H.
,
Stauffer
,
D. B.
, and
Engleman
,
R. R.
, 1994,
Fuel Cells: A Handbook
,
3rd revision
,
Gilbert and Commonwealth
,
Inc. Philadelphia
, U.S. Department of Energy, Contract No. DE-AC01–88FE61684.
9.
EG&G Technical Services, Inc.
, 2002,
Fuel Cell Handbook
,
6th ed.
, DOE/NETL-2002/1179, Under Contract No. DE-AM26–99FT40575 U.S. Department of Energy, Office of Fossil Energy, National Energy Technology Laboratory.
10.
Chan
,
S. H.
, and
Xia
,
Z. T.
, 2002, “
Polarization Effects in Electrolyte/Electrode-Supported Solid Oxide Fuel Cells
,”
J. Appl. Electrochem.
0021-891X,
32
, pp.
339
347
.
11.
Chan
,
S. H.
,
Khor
,
K. A.
, and
Xia
,
Z. T.
, 2001, “
A Complete Polarization Model of a Solid Oxide Fuel Cell and its Sensitivity to the Change of Cell Component Thickness
,”
J. Power Sources
0378-7753,
93
, pp.
130
140
.
12.
Kanamura
,
K.
,
Yoshioka
,
S.
, and
Takehara
,
Z.
, 1991, “
Dependence of Entropy Change of Single Electrode on Partial Pressure in Solid Oxide Fuel Cell
,”
J. Electrochem. Soc.
0013-4651,
138
(
7
), pp.
2165
2168
.
13.
Takehara
,
Z.
,
Kanamura
,
K.
, and
Yoshioka
,
S.
, 1989, “
Thermal Energy Generated by Entropy Change in Solid Oxide Fue Cell
,”
J. Electrochem. Soc.
0013-4651,
136
(
9
), pp.
2506
2512
.
14.
Herle
,
J. V.
,
Membrez
,
Y.
, and
Bucheli
,
O.
, 2004, “
Biogas as a Fuel Source for SOFC co-Generators
,”
J. Power Sources
0378-7753,
127
(
1–2
), pp.
300
312
.
15.
Matsuzaki
,
Y.
, and
Yasuda
,
I.
, 1999, “
RelAtionship Between the Steady-State Polarization of the Sofc Air Electrode, La0.6Sr0.4MnO3+δ∕YSZ, and its Complex Impedance Measured at the Equilibrium Potential
,”
Solid State Ionics
0167-2738,
126
(
3–4
), pp.
307
313
.
16.
Costamagna
,
P.
,
Costa
,
P.
, and
Antonucci
,
V.
, 1998, “
Micro-Modelling of Solid Oxide Fuel Cell Electrodes
,”
Electrochim. Acta
0013-4686,
43
(
3–4
), pp.
375
394
.
17.
Sunde
,
S.
, 1997, “
Calculations of Impedance of Composite Anodes for Solid Oxide Fuel Cells
,”
Electrochim. Acta
0013-4686,
42
(
17
), pp.
2637
2648
.
18.
Tanner
,
C. W.
,
Fung
,
K. Z.
, and
Virkar
,
A. V.
, 1997, “
The Effect of Porous Composite Electrode Structure on Solid Oxide Fuel Cell Performance: I—Theoretical Analysis
,”
J. Electrochem. Soc.
0013-4651,
144
(
1
), pp.
21
30
.
19.
Chan
,
S. H.
,
Low
,
C. F.
, and
Ding
,
O. L.
, 2002, “
Energy and Exergy Analysis of Simple Solid-Oxide Fuel-cell Systems
,”
J. Power Sources
0378-7753,
103
, pp.
188
200
.
20.
Utgikar
,
P. S.
,
Dubey
,
S. P.
, and
Prasada Rao
,
P. J.
, 1995, “
Thermoeconomic Analysis of Gas Turbine Cogeneration Plant—A Case Study
,”
Proc. Inst. Mech. Eng., Part A
0957-6509,
209
(
3
), pp.
45
54
.
21.
Bedringås
,
K. W.
,
Ertesvåg
,
I. S.
,
Byggstøyl
,
S.
, and
Magnussen
,
B. F.
, 1997, “
Exergy Analysis of Solid-Oxide Fuel-Cell (SOFC) Systems
,”
Energy
0360-5442,
22
, pp.
403
412
.
22.
Iwahashi
,
T.
,
Yoshida
,
N.
, and
Kosaka
,
H.
, 1998, “
High Efficiency Power Generation From Coal and Wastes Utilizing High Temperature Air Combustion Technology: Thermal Performance of Compact High Temperature Air Preheater and Meet Boiler
,”
Proceedings of the International Symposium on Advanced Energy Technology
, Sapporo, Japan, Hokkaido University, pp.
455
462
.
23.
Larminie
,
J.
, and
Dicks
,
A.
, 2003,
Fuel Cell Systems Explained
,
Wiley
,
London
.
24.
Dunbar
,
W. R.
,
Lior
,
N.
, and
Gaggioli
,
R. A.
, 1991, “
Combining Fuel Cells with Fuel-Fired Power Plants for Improved Exergy Efficiency
,”
Energy
0360-5442,
16
(
10
), pp.
1259
1274
.
You do not currently have access to this content.