Thermo-economic appraisal and operating fluid selection of geothermal-driven ORC configurations integrated with PEM electrolyzer

In this paper, a thermoeconomic layout of a renewable production unit embracing a geothermal-based proton exchange membrane (PEM) electrolyzer integrated with the organic Rankine cycle (ORC) is expressed with respect to exergetic, energetic, and exergoeconomic points of view. First, some probable amendments to the base ORC plant design are here poked and collated to boost the ORC recovery efficiency; ORC systems with the in-ternal heat exchanger (IHE), open feed organic fluid heater (OFOH), closed feed organic fluid heater (CFOH), and a combination of IHE-CFOH is assessed. The exergy destruction rate, net present value, exergy destruction ratio, and exergy flow diagram of all ORCs are evaluated. Afterward, the best configuration with seven various ORC operating fluids is scrutinized by optimization of its NPV, cost rate, exergy efficiency, and hydrogen production rate using LINMAP, TOPSIS, and Shannon Entropy, as well as the VIKOR decision makings, and Gray Wolf Optimizer. The results have indicated that the optimum payback period is 5.07 years, and total destruction is 599.13 kW can be obtained with ORC/IHE-PEM operated with R113. Moreover, the optimal condition reveals the optimum cost rate, hydrogen production rate, and exergy efficiency of 26.32 $/hr, 4.202 kg/h, and 40.66%, respectively.