Liquid Antimony Anode for Converting Sulfur-Containing Coal in Direct Carbon Fuel Cells

Abstract

Liquid antimony anodes (LAAs) are carbon-converting anodes for direct carbon fuel cells (DCFCs), and they have been intensively studied over the last decade because of their decent performance. Though several previous researches have demonstrated the capability of LAAs in carbon oxidation, reaction mechanisms between the LAA and the impurities in the solid carbon fuels, e.g., sulfur, remains largely unknown. In the present research, H2S and pyrite were introduced into the anode, respectively, as the sources of sulfur. The fuel cell was first discharged under 1000 ppm of H2S continuously for over 10 h. At the same time, we used mass spectrometer (MS) to monitor the composition of its flue gas. The performance of the cell remained mostly unchanged under the H2S atmosphere throughout the test, and the lower sulfur concentration in the off-gas stream suggested that the LAA trapped most of the sulfur within itself. In the case of pyrite, the performance of the cell remained stable during the 20-h test, despite the relatively large amount of sulfur fed into the system. The experimental results demonstrated that the LAA is resistive against the sulfur poisoning and able to handle fuels with a high level of sulfur content.