Renewable acetic acid in combination with solid oxide fuel cells for sustainable clean electric power generation

The feasibility of renewable acetic acid as a direct fuel of SOFCs for sustainable electric power generation was investigated. To solve the problem of carbon deposition over conventional nickel cermet anodes, an advanced catalyst for acetic acid catalytic decomposition/internal reforming reaction was exploited. A comparative study of coke formation over Ni/Al₂O ₃, Ni/MgO-Al₂O₃ and Ni-YSZ catalysts was conducted by oxygen-temperature programmed oxidation analysis. We found that the Ni/MgO-Al₂O₃ catalyst is much superior to the other two catalysts in suppressing carbon deposition, especially under the condition of the presence of steam in the acetic acid fuel. Various cells were fabricated and tested under different conditions. The differences in OCVs and power outputs of the cells caused by the usage of hydrogen and acetic acid as fuels were studied and explained based on the thermodynamic calculation and EIS measurement. After optimization, a peak power density of 1325 mW cm^-2 at a furnace temperature of 800°C was achieved for the cell with a catalyst layer operating on acetic acid fuel. The cell was successfully operated continuously on acetic acid-steam fuel for a period of at least 200 h without any noticeable performance degradation, delamination of the catalyst layer and carbon deposition. The promising results of this work show the possibility of better utilization of the abundant bio-mass or bio-oil for future energy generation.