Solar-to-Fuel Energy Conversion Analysis of Solarised Mixed Reforming of Methane

Abstract

Abstract An energetic upgrade factor has been defined as the ratio of the lower heating value (LHV) of the syngas (H 2 plus CO) produced plus unreacted feedstock to that of the feedstock processed. It is used to evaluate the thermal performance of the steam reforming of methane,mixed reforming of methane with steam and carbon dioxide, and carbon dioxide reforming of methane based on the calculated equilibrium product compositions. A non-stoichiometric equilibrium model was developed using FactSage 6.3 software to conduct the thermodynamic calculations for production of syngas. The results show that increasing temperature or decreasing pressure can enhance the energetic upgrade factor of all three reforming processes. The ratio of the feedstock components has an effect on the energetic upgrade factor for the three reforming processes. There is an optimum ratio exisitng that provides the highest energetic upgrade factor for each of the three reforming processes. Replacement of H 2 O by CO 2 can enhance the energetic upgrade factor, particularly at high temperatures with no carbon formation. The analysis also identifies operating regimes where carbon formation is thermodynamically possible as well as discusses the undesirable effect that this carbon formation has on the energetic upgrade factor.