Thermodynamic and exergo-economic analyses of an innovative semi self-feeding energy system synchronized with waste-to-energy technology

In this research, a novel integration is presented to develop a hydrogen-based strategy solution for 600 kW electrical power production. The proposed system consists of solid oxide fuel cell (SOFC), gas turbine, organic Rankine cycle (as the Waste-to-Energy technology), and a proton exchange membrane (PEME). PEME utilizing as a hydrogen production unit in order to cover a portion of SOFC fuel consumption rate and utilizing a waste-to-energy technology to provide more electricity generation are the distinguishing feature of proposed integration. The parametric analysis explores the effects of significant variables (such as the fuel cell current density, compressor pressure ratio, and organic Rankine cycle turbine inlet temperature on the system performance. The corresponding analysis provides such important following results: (1) increasing the SOFC's current density over a range of 2000–8000 (A/m2) decreases the energy and exergy efficiencies respectively from 17.92% to 12.74% and from 54.98% to 30.26%, (2) Although high overall exergy efficiency is achieved by reducing the compressor pressure ratio. By considering specific thermodynamic conditions which are obtained by parametric analysis, exergy and exergo-economic results reveal that the after-burner is identified as the component with maximum exergy destruction rate (21.44% of total) and it has the lowest value of the exergo-economic factor (0.006%) due to high thermodynamic inefficiencies, while the organic turbine has the highest exergo-economic factor 90.34% due to its high investment cost. Also, the net exergy efficiency results as 45% and levelized cost of electricity (LCOE) results as 0.102 $/kWh.