Synergistic Evaluation between Decoupled Electrolysis for Water Splitting and Liquid-Organic Hydrogen Carrier (LOHC) Systems: A Simulation Study

Abstract

The combination of two innovative processes for hydrogen production and storage is presented and evaluated. The first process, named Electrochemical thermally Activated Chemical (ETAC) cycle, involves the temporal decoupling of hydrogen production, while the second process involves the hydrogenation of an organic molecule (methylcyclohexane, MTH). The models for ETAC and MTH systems are implemented on Aspen Plus, assuming a cycle behavior computed with calculator blocks, and validated against experimental data. Simulation studies are performed, including parametric sensitivity analysis, to evaluate effects of applied load, temperature, and pressure. Finally, an energy analysis is performed to assess the efficiency of the overall system. The study revealed that integrating thermically both processes (ETAC + MTH) is advantageous as it leads to an overall increase of energy efficiency compared to commercially available solutions. In addition, this work addresses the issue of the limitations of these technologies and proposes a cost analysis, particularly for the ETAC System. This manuscript provides an innovative approach for Power-to-H2, addressing actual challenges towards an efficient use of renewable energy.