High temperature electrolyte supported Ni-GDC/YSZ/LSM SOFC operation on two-stage Viking gasifier product gas

• Published in: Journal of power sources Vol. 173; no. 1; pp. 357 - 366
• Main Authors: Hofmann, Ph, Schweiger, A., Fryda, L., Panopoulos, K.D., Hohenwarter, U., Bentzen, J.D., Ouweltjes, J.P., Ahrenfeldt, J., Henriksen, U., Kakaras, E.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 08-11-2007; Elsevier Sequoia
• Subjects: Applied sciences; Biomass; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Nickel gadolinium-doped ceria oxide; Solid oxide fuel cell; Two-stage gasification; Wood gas; Wood gas; Biomass; Nickel gadolinium-doped ceria oxide; Two-stage gasification; Solid oxide fuel cell; Power density; Scanning electron microscopy; Anode; Wood; Voltage current curve; Stabilized zirconia; High temperature; Cerium oxide; Gadolinium oxides; Gasification; Nickel; Humidification; Microstructure; Current density; Nickel oxide
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2007.04.073

This paper presents the results from a 150
h test of a commercial high temperature single planar solid oxide fuel cell (SOFC) operating on wood gas from the Viking two-stage fixed-bed downdraft gasifier, which produces an almost tar-free gas, that was further cleaned for particulates, sulphur and tar traces. The chosen SOFC was electrolyte supported with a nickel/gadolinium-doped cerium oxide (Ni-GDC) anode, known for its carbon deposition resistance. Through humidification the steam to carbon ratio (S/C) was adjusted to 0.5, which results in a thermodynamically carbon free condition at the SOFC operating temperature
T
=
850
°C. The cell operated with a fuel utilisation factor (
U
f) around 30% and a current density of 260
mA
cm
−2 resulting in an average power density of 207
mW
cm
−2. Throughout the duration of the test, only a minor cell overpotential increase of 10
mV was observed. Nevertheless, the
V–
j (voltage–current density) curves on H
2/N
2 before and after the wood gas test proved identical. Extensive SEM/EDS examination of the cell's anode showed that there was neither carbon deposition nor significant shifts in the anode microstructure or contamination when compared to an identical cell tested on H
2/N
2 only.