Thermodynamic performance assessment of a geothermal energy assisted combined system for liquid hydrogen generation

The main goal of this work is to achieve comprehensively performance and environmental examines of the geothermal based integrated plant for useful commodities. For this purpose, the geothermal energy-assisted system having different sub-systems is proposed, which are the Kalina Cycle, Organic Rankine Cycle (ORC), hydrogen production, and hydrogen liquefaction sub-processes. Energy, exergy, environment, and sustainability assessments are performed by using different thermodynamic equilibrium. In this regard, the effects of some significant indicators such as reference temperature, geothermal water temperature, and turbines' isentropic efficiency, on the proposed plant performance are addressed. In addition, for a sustainable future, the carbon dioxide emission and sustainability index are evaluated. Performance analyses of the system indicated that the energetic and exergetic efficiencies of the studied model are 25.62% and 52.69%. Furthermore, the energy and exergy analyses of the hydrogen generation and liquefaction subsystem are computed as 27.89% and 46.62%. Besides, exergy destruction analysis is performed to evaluate the irreversibilities of geothermal energy-based plant's components and the highest exergy destruction is seen in the heat exchanger 2. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.