Sustainable Hydrogen Storage and Methanol Synthesis Through Solar-Powered Co-Electrolysis Using SOEC

Abstract

Syngas rich in hydrogen, generated through renewable-powered co-electrolysis of water (H₂O) and carbon dioxide (CO₂) using solid oxide electrolysis cells (SOEC), have gained significant attention due to its high efficiency and conversion rates. This method offers a promising solution for mitigating global warming and reducing CO₂ emissions by enabling the storage of intermittent renewable energy. This study investigates solar-integrated co-electrolysis of H₂O and CO₂ via SOEC to produce hydrogen-rich syngas, which is then utilized for methanol synthesis through a series of heat exchangers and compressors. Parabolic dish solar collectors supply thermal energy, while photovoltaic modules provide electricity for SOEC operation. CO₂ from industrial processes is captured and combined with steam at the SOEC inlet for co-electrolysis. The proposed system is modeled using engineering equation solver software, incorporating mass, energy, and exergy balance equations. The system's performance is analyzed by varying key parameters such as direct normal irradiance, heat exchanger effectiveness, current density, cell temperature, and pressure. The proposed system achieves a solar-to-fuel efficiency of 29.1%, with a methanol production rate of 41.5 kg per hour. Furthermore, an economic analysis was conducted to determine the levelized cost of fuel.