Thermodynamic performance comparison of a SOFC system integrated with steam reforming and dry reforming by utilizing different fuels

Abstract

This work investigates the thermodynamic analysis of syngas production from several fuels by steam reforming or dry reforming for SOFC-integrated systems. Four commonly used fuels are considered: methanol and glycerol (alcohols), methane, and diesel (hydrocarbons). The integrated system is modeled on Aspen Plus using the Gibbs free energy minimization method and a generic electrochemical model to assess the effect of critical parameters on system performance. The results indicate a carbon-free zone within the reformer, and alcohols provide better resistance to carbon deposition than hydrocarbon fuels. Elevating the reforming temperature and STCR/CTCR increases the hydrogen concentration of syngas while also avoiding carbon deposits in the external reformer. Increasing the temperature and fuel utilization factor of SOFCs has been found to enhance electrical efficiency but at the expense of diminished thermal and total efficiency. For given operating conditions, the electrical efficiencies of methanol, glycerol, methane, and diesel are observed to be 47%, 46%, 51%, and 49% for the SR-SOFC system, and 45%, 42%, 42%, and 33% for the DR-SOFC system, respectively. The methane-SR-SOFC and methanol-DR-SOFC systems have the highest electrical efficiency, while diesel is unsuitable for the DR-SOFC system. This work can advise engineers to select the appropriate fuel types and reform technologies for SOFC-integrated systems.