Performance assessment of a combined heat and power system: A novel integrated biomass gasification, solid oxide fuel cell and high-temperature sodium heat pipe system part I: Thermodynamic analysis

Abstract

In this study, a thermodynamic assessment of an integrated solid oxide fuel cell (SOFC) with a steam biomass gasification and high-temperature sodium heat pipes for combined heating and power production as a cogeneration system is conducted. In this regard, rice husk is used as feedstock. The modeling and analysis of the system is performed using mass and energy conservation laws and equilibrium constants. The results of the extended model are confirmed by experimental results. The effect of steam to biomass ratio (STBR) on the performance of the system is investigated. According to the results, more number of heat pipes and higher heat rate of gasification are needed at high STBR. Also, the effects of key parameters including the current density, the fuel utilization ratio (Uf), and the fuel cell temperature are studied on the produced power and electrical, thermal, and total efficiencies. The results indicate that the produced power and electrical and total efficiencies of the integrated system enhance by increasing temperature whiles increasing the current density decreases the total efficiency. By selecting the processing parameters at their optimum levels, the outputs are achieved as the power of 208 kW, the electrical efficiency of 43.71%, the thermal efficiency of 30.6%, and the total efficiency of 74.31%.