Optimization of a biomass-driven Rankine cycle integrated with multi-effect desalination, and solid oxide electrolyzer for power, hydrogen, and freshwater production

The current work is a study of electricity, hydrogen, and freshwater polygeneration system fueled by biomass fuel. Accordingly, innovative integration of a Rankine cycle, a multi-effect desalination, and a solid oxide electrolyzer cell has been considered utilizing a syngas production biomass combustion chamber. The waste heat and a part of the output electricity of the Rankine cycle have been employed to launch the desalination and electrolyzer units, respectively. The suggested polygeneration is analyzed from the thermodynamic and exergoeconomic viewpoints through developing a code in engineering equation solver software and a multi-criteria optimization via MATLAB software. Hence, the NSGA-II optimization method and decision-making TOPSIS technique have been implemented. The parametric study has been conducted based on the effect of biomass fuel mass flow rate, turbine inlet pressure, combustion chamber outlet temperature, and pinch point temperature difference of the steam generator on the thermodynamic and exergoeconomic variables of the whole system. Considering the total exergy destruction rate, exergy efficiency, and total unit exergy cost of products as objective functions, the suggested system achieved the optimum values of 17.64%, 7658.5 kW, and 26 $/GJ corresponding for these variables.