The sulfur issue in Fuel Cell based cogenerative systems

In a context in which climate changes due to the continuous and out of control use of fossil fuels are becoming always more significant, it is very important to try to foster energy conversion systems with a lower environmental impact such as FC-based cogenerative systems. With the necessary precautions, this kind of systems can be feed with a wide range of fuels, from the most conventional, such as hydrogen and natural gas, to those produced from renewable sources, such as biogas or gasification gas. Unfortunately, most of these fuels contains traces of elements that result to be detrimental for FC-based systems operation. Among the different damaging substances, in the present work, the focus has been addressed to sulfur and sulfur-based compounds. Referring to this type of contaminant, usually a distinction can be made between the “natural” sulfur that is usually intrinsically present in the fuel adopted, according to its origins and processing procedures, and the “artificial” sulfur that can be added to the fuel depending on the specific use to which it is addressed, such the odorisation of the Natural Gas (NG). In the prosecution, some scenarios of management of the issues correlated to the presence of sulfur and sulfur-based components (especially H2S) will be presented as examples. For each of them, the current methods adopted in order to guarantee the correct and safe operation of these devices are described. In addition, where existing, some possible alternative solutions are supplied.