Investigation of Direct-Fed Solid Oxide Fuel Cell Fueled by Upgraded Bio-Oil Extracted from Olive Waste Pyrolysis: Part 1: Bio-Oil Characterization and Preliminary Cell Testing

Abstract

This study is one component of a two-part paper aiming to investigate the feasibility of directly feeding renewable liquid biofuels in Solid Oxide Fuel Cells (SOFCs). In part 1, we examined changes that occur in the physicochemical properties upon upgrading process via catalytic esterification of fast pyrolysis crude bio-oil and we preliminary analyzed and compared the influence on the power outputs of SOFCs. Upgraded bio-oil was characterized revealing that all acid groups present in the crude bio-oil were totally converted to esters. The H/C ratio increased while the O/C ratio decreased upon upgrading. Upgraded bio-oil composition is comprised mostly of aliphatic groups (60 %) followed by saturated methyl esters (30 %). Upgraded bio-oil viscosity (2.78 cP), neutrality (pH≈7) and energy density (40.94 MJ kg−1) were considerably enhanced. SOFC electrochemical performance results are promising showing that current density increases by 1.7 and ≈2 times while peak power density increases by 1.6 and 3 times upon upgrading at 700 °C and 750 °C, respectively.