Energy, exergy, environmental, and economic evaluations of a proposed CCHP system based on solar, biomass, SOFC, micro-turbine, and LiBr/water absorption chiller

Abstract

A solid oxide fuel cell-based CCHP system that uses biomass fuel has been developed as part of this research. The system includes a solar collector subsystem and a downward gasifier that preheats the gasification agent to convert biomass into synthesis gas for the fuel cell and to preheat the air used in the gasifier. The system underwent energy, exergy, environmental, and economic studies. The results showed that preheating the air entering the gasifier increases the amount of CO and H₂ in the synthesis gas while decreasing the amount of CO₂. An exergy analysis of the system revealed that the gasifier, fuel cell, and gasifier accounted for 47.83 % of the total exergy loss. The fuel cell alone contributed to 17.66 % of the exergy destruction within the system. The environmental analysis concluded that the proposed CCHP system has low CO₂ gas emissions and higher efficiencies than similar power generation and power and heat production systems. Therefore, the presented system is highly compatible with the environment. The study found that the cost of the fuel cell accounted for 50.07 % of the overall cost of the system. The NPV of the proposed system increased after 7 years based on the system's payback period of 6.2 years and amounted to 357,000 € at the end of the system's lifespan, which is 10 years.