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Exploration of Complex Electrochemical and Chemo‐mechanical Behavior of Solid Oxide Fuel Cell Fueled with Pyrolysis Bio‐oil
Author(s) -
Elleuch A.,
Halouani K.,
Li Y.
Publication year - 2018
Publication title -
fuel cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.485
H-Index - 69
eISSN - 1615-6854
pISSN - 1615-6846
DOI - 10.1002/fuce.201700074
Subject(s) - anode , biochar , pyrolysis , chemical engineering , microbial fuel cell , oxide , solid oxide fuel cell , electrochemistry , materials science , pyrolysis oil , polarization (electrochemistry) , chemistry , electrode , metallurgy , engineering
Direct utilization of olive mill wastewater sludge (OMWS) bio‐oil prepared via fast pyrolysis in a Direct‐Biofuel Solid Oxide Fuel Cell (DB‐SOFC) was investigated. A viable power densities (>1,000 W m −2 at 650 °C) and 6 h operation under open circuit conditions were obtained despite crude bio‐oil complex chemistry. When heated, bio‐oil decomposes yielding gases, volatiles and solid residues (biochar). At 650 °C, polarization curve and impedance spectra of SOFC fed by bio‐oil showed peculiar shapes related to complex kinetics and charge transfer mechanism within the anode. The carbon accumulation at 650 °C is managed through oxidations with oxide ions and chemical reaction with CO 2 and H 2 O gases. Above 700 °C, performance degradation was noted related to biochar accumulation at the anode though the promotion of Boudouard reaction, the increase in O 2− transfer and possible carbon electrochemical oxidations. The anode chemo‐mechanical instability was observed explaining the rise in cell ohmic resistance and performance degradation after 6 operating hours. Globally, this work demonstrates that direct fed SOFCs with OMWS bio‐oil is achievable using Ni‐SDC anode but enhancement in fuel quality and in anode catalytic activity and stability are required to improve significantly the cell performance.