A novel hybrid process with a sustainable auxiliary approach concerning a biomass-fed solid oxide fuel cell and triple-flash geothermal cycle

Abstract

Designing a multi-source system provides a higher performance from energy and economic viewpoints. Hence, an innovative two-part hybrid process with a sustainable auxiliary approach is proposed. The first part relies on a solid oxide fuel cell power plant feeding biomass fuel, and the second one utilizes a triple-flash geothermal cycle equipped with a domestic water heater, an ejector refrigeration cycle, and a water electrolysis unit responding to some urban utilities. The proposed system is analyzed from the energy, exergy, economic, and environmental standpoints. Besides, a multiple objective optimization is considered in four different scenarios to identify the most suitable optimum state. The system produces 3853 kW net power, 2158 kW cooling load, 1588 kW heating load, and 0.36 kg/h hydrogen, leading to 59.92% exergetic efficiency and 16.68 M$ net profit at the base condition. Accordingly, the steam turbines have the highest cost rate, and the ejector contains the highest exergy destruction rate. Also, the SOFC current density significantly impacts the total exergetic efficiency and exergy destruction rate. Eventually, the exergy-environmental scenario represents the best optimum state in which the exergetic efficiency, levelized total emission, and net profit are achieved at 64.82%, 0.2 ton/MWh, and 17.38 M$, respectively.