Proposal and multi-criteria optimization of a novel biomass-based and PEMfuel cell system for generating clean power for building applications

The current research presents a novel integrated energy system to generate clean and sustainable power for building applications. The system uses a proton exchange membrane (PEM) fuel cell to generate power and heat from syngas, as well as a dual-ejector organic flash cycle (DOEFC) to recover waste heat from the upper process efficiently. From a technological, economic, and environmental aspect, the system is examined. To figure out the system's best operation point, a two-criteria optimization is shown to seek the lower cost and emission as well as higher efficiency of the system. Moreover, a parametric study is performed to reveal the influence of several key parameters on the system performance. The results pinpoint that this system has energy and exergy efficiencies that are around 37.65% and 23.77%, respectively. Among the components of this system, Afterburner (5.84 MW), PEM-FC (5.04 MW), and selective CO oxidizer (3.32 MW) are responsible for the greatest amount of exergy destruction rate. In addition, it is worthy noting that, the highest contribution of the total exergy destruction due to the irreversibilities of the fuel cell. Furthermore, the results of this system's two-objective optimization show that the best solution point has a net output power of 2.66 MW and a total cost rate of 5.39 $/h.