Case Studies in Thermal Engineering (Apr 2024)
Comprehensive optimization of an integrated energy system for power, hydrogen, and freshwater generation using high-temperature PEM fuel cell
Abstract
Modern energy conversion technologies with low or no emissions are needed to achieve sustainable development goals. This research examines the thermodynamic and exergy-economic features of a high-temperature proton exchange membrane fuel cell. A cutting-edge, integrated energy system uses high-temperature proton exchange membrane fuel cells, an organic Rankine cycle, a proton exchange membrane electrolyzer, and a multi-effect desalination unit. This setup generates electricity, hydrogen, and fresh water. Methanol-steam reformation produces hydrogen for the fuel cell. The recommended cycle drives an organic Rankine power producing cycle using 120–200 °C waste heat from high-temperature proton exchange membrane fuel cell to power water electrolysis and hydrogen generation. An integrated method incorporates energy and exergy balances and cost analysis to assess the proposed system's exergetic, economic, and environmental impacts. The suggested integration delivers high energy and exergy efficiency at an acceptable cost and environmental effect. According to parametric research, boosting the fuel cell's working temperature decreases production costs and carbon dioxide emissions per mass. Raising current density has positive technical and environmental impacts. As the current density increases from 0.4 to 0.8 (A/cm2), the net power generation increases to 46.67% and the exergy efficiency increases from 64.5% to 68%. An increase in multi-effect distillation motivate steam pressure from 200 to 600 kPa results in an increase in the daily freshwater generated from 111.68 m3 to 116.41 m3. For environmental protection and output optimization, fuel utilization ratio must be reduced. The ideal system's exergy efficiency, product unit cost, and environmental impact are 65.78%, 86.28 ($/h), and 4.33%, respectively.
