Abstract
The higher volumetric energy density of ammonia compared to liquid and compressed hydrogen makes it an attractive carbon-free fuel for long-distance transport, especially in the maritime sector. A solid oxide fuel cell (SOFC) can in principle be operated directly using ammonia as the high operating temperature (above 650 °C) and the use of a Ni-based fuel electrode facilitate internal cracking to nitrogen and hydrogen. A similar performance should be achievable when fueling with NH3 or an equivalent H2/N2 mixture, although there are some uncertainties and conflicting reported results regarding the durability of cells and stacks exposed to ammonia.
One of the challenges of evaluating degradation of SOFCs fueled with ammonia is understanding the extent of cracking before the gas reaches the cell. Heated steel- or Inconel-based gas tubing and/or cell housing can contribute to significant degree of cracking depending on operating temperature, thus complicating the degradation evaluation. In this work, gas analysis was used to measure the decomposition of ammonia under typical testing conditions using different set-ups and materials for gas supply.
One of the challenges of evaluating degradation of SOFCs fueled with ammonia is understanding the extent of cracking before the gas reaches the cell. Heated steel- or Inconel-based gas tubing and/or cell housing can contribute to significant degree of cracking depending on operating temperature, thus complicating the degradation evaluation. In this work, gas analysis was used to measure the decomposition of ammonia under typical testing conditions using different set-ups and materials for gas supply.