Performance degradation of Molten Carbonate Fuel Cells caused by SO2 in simulated flue gas
(English)Manuscript (preprint) (Other academic)
The effect on MCFC performance degradation SO2 contaminant at the cathode, in combination with operating the fuel cell with CO2 lean oxidant gas, simulating combustion flue gas, was evaluated. Of special focus was the effect of electrolyte degradation.
Measurements were performed to test the effect of SO2 in the oxidant gas stream, followed by regeneration with clean gas. A 3cm2 button cell MCFC allowing active electrolyte management by refilling was for 1500h to benchmark the performance degradation without contaminants. In order to study the poisoning effect of SO2 entering the fuel cell gas, the MCFC was operated for 250h with the addition of 18ppm SO2 in the oxidant gas. Electrolyte was added after 1500h of benchmark operation and after 250h of contaminant operation. The addition of 18ppm SO2 greatly accelerated the performance degradation of the fuel cell. Measurements showed that the internal resistance was the single factor which was most affected by the SO2 poisoning, and that the performance degradation after 250h was not reversed by regeneration with clean gas, but with the addition of fresh electrolyte. This led us to conclude that SO2 in oxidant gas leads to an accelerated loss of electrolyte and subsequent decrease in conductivity of the electrolyte, causing loss of performance and meeting end of life criteria after relatively short operational time. Other factors, such as poisoning of the anode and corrosion of cathode side current collectors, were also detected.
Molten Carbonate Fuel Cell, MCFC, CO2 separation, flue gas, SO2 contaminant
Other Chemistry Topics
Research subject Chemical Engineering
IdentifiersURN: urn:nbn:se:kth:diva-154584OAI: oai:DiVA.org:kth-154584DiVA: diva2:757948
FunderEU, European Research Council, 245171
QS 20142014-10-232014-10-232014-10-28Bibliographically approved