Multi-criteria optimization of a biomass-fired proton exchange membrane fuel cell integrated with organic rankine cycle/thermoelectric generator using different gasification agents

In this work, a biomass-fired proton exchange membrane fuel cell integrated with organic Rankine cycle and thermoelectric generator using different gasification agents is proposed for the cogeneration of power and heat as well as hot water production. Both models are comprehensively analyzed and compared from thermodynamic, thermoeconomic, and environmental aspects. A parametric study is performed to evaluate the influence of major decision parameters on the output power, energy and exergy efficiencies, CO2 emission index, and total cost rate of both models. Furthermore, the best model is optimized using genetic algorithm method in MATLAB. The results reveal that using steam as the gasification agent is more suitable in terms of economic and environmental performance indicators. Referring to the exergy and exergoeconomic assessment, in both models, afterburner is one of the significant sources of irreversibility and proton exchange membrane fuel cell has the highest cost of inefficiencies. Results of multi-objective optimization indicate that the output power and total cost rate of the model using steam as the gasification agent are 1.849 kW and 5.094 $/h. Moreover, scatter distribution of the significant variables shows that biomass moisture content and figure of merit are sensitive variables that should be kept at their lowest value.