Thermoeconomic analysis of pressurized hybrid SOFC systems with CO2 separation

In this paper, the results of the thermodynamic and economic analyses of distributed power generation plants (1.5 MWe) are described and compared. The results of an exergetic analysis are also reported, as well as the thermodynamic details of the most significant streams of the plants. The integration of different hybrid solid oxide fuel cell (SOFC) system CO2 separation technologies characterizes the power plants proposed. A hybrid system with a tubular SOFC fed with natural gas with internal reforming has been taken as reference plant. Two different technologies have been considered for the same base system to obtain a low CO2 emission plant. The first technology involved a fuel decarbonization and CO2 separation process placed before the system feed, while the second integrated the CO2 separation and the energy cycle. The first option employed fuel processing, a technology (amine chemical absorption) viable for short-term implementation in real installations while the second option provided the CO2 separation by condensing the steam from the system exhaust. The results obtained, using a Web-based Thermo Economic Modular Program software, developed by the Thermochemical Power Group of the University of Genoa, showed that the thermodynamic and economic impact of the adoption of zero emission cycle layouts based on hybrid systems was relevant.