Experimental and Numerical Study of Molten Carbonate Fuel Cells Working in Reversible Mode

Abstract

Molten Carbonate Fuel Cells (MCFCs) have a great potential to help facing the global warming problem. MCFCs have the characteristics that can be used as a fuel cell to produce electricity, can be used as a carbon capture and sequestration device helping to manage the carbon dioxide emissions, as well as an electrolyzer to produce hydrogen or synthesis gas using carbon dioxide and water as fuels. The scope of this thesis is to test experimentally and predict numerically the performance of a single MCFC in reversible mode, i.e., the cell operates switching between fuel cell mode (MCFC) and electrolysis mode (Molten Carbonate Electrolysis Cell, MCEC) in order to obtain more knowledge for the conditions that increase the electrical power or hydrogen production, respectively. Therefore, three experimental campaigns were carried out in order to study the performance of a single cell operating: 1) in fuel cell mode, 2) in reversible mode, and 3) in electrolysis mode through a long-term test. The single cell tested has an electrode-electrolyte interface area of 80 cm2. The aim of the first experimental campaign was to collect experimental data of the cell operating as MCFC which help to compare the cell performance with five different zero-dimensional models. Then, one model was selected in order to fit with the experimental data in fuel cell mode. During the second experimental campaign different operative parameters were tested in reversible mode to collect data in both operative modes. The fitted model was then compared in electrolysis mode with the experimental data acquired on the cell running in reversible mode. The program code was written in Anaconda Python 3.7. Finally, in the third experimental campaign, the cell was tested in electrolysis mode for almost 1000 h with the aim of studying the potential to operate the single cell as an electrolyzer.