A conceptual hydrogen, heat and power polygeneration system based on biomass gasification, SOFC and waste heat recovery units: Energy, exergy, economic and emergy (4E) assessment

Integrated polygeneration systems have emerged as an effective and sustainable solution for maximizing the utilization of renewable fuels, and offer multiple economic and environmental advantages. This work proposes a new polygeneration system to produce hydrogen, heat, and power based on integrating biomass gasification, solid oxide fuel cell, gas turbine, organic Rankine cycle, and supercritical CO2 Brayton cycle. The proposed system is simulated in Aspen Plus, and the performance is evaluated based on energy, exergy, economic, and emergy analyses. The overall energy and exergy efficiencies attain 76.82% and 60.64%, respectively. The levelized cost of hydrogen is 4.06 $/kg, comparable to those reported in the literature, and the yearly income generated through revenue sales of hydrogen, heat, and electricity can reach up to 58.42 M$. The emergy analysis showed that the system depends on purchased inputs but can efficiently use the available resources to generate valuable products. The hybrid system has low environmental impacts in the long term. It can serve as a low-cost, low-carbon, and profitable polygeneration system of hydrogen, heat, and power, with a good quality of energy conversion.