Innovative Models for Hydrogen Storage: A Study on Thermal Management and Hybrid Systems

Energy storage systems are pivotal in efficiently integrating renewables into the grid for achieving a net-zero energy system. Hydrogen is increasingly recognized as a viable alternative to electric batteries for long-term and high-capacity storage. This paper presents the dynamic performance of an integrated Power-to-Power system, employing a dual approach. This involves the implementation of a hybrid storage solution that utilizes both physisorption and chemisorption, coupled with the modeling of the thermal management system. This study builds upon prior research focused on hydrogen storage at room temperature and medium-high pressure. The extension involves expanding the hydrogen storage system model to operate at lower temperatures and pressures, aiming to increase the hydrogen storage capacity and operating conditions. The storage tank is kept at a fixed temperature through a thermal management model based on cooling cycles modeled in Aspen Hysys. Low temperatures are needed to improve the adsorption processes, while heat is applied to accelerate the release of hydrogen molecules trapped within the material. Heat is fed to the system by a heating wire. Subsequently, it investigates the effectiveness of a hybrid hydrogen storage system by integrating an additional chemisorption tank to the already existing physisorption tank, while maintaining original temperature and volume conditions. This hybrid approach seeks to merge the rapid response capability of physisorption with the long-term stability offered by chemisorption. The study evaluates four different materials, including MOFs and activated carbon, and their performance compared to a simpler compressed hydrogen storage system. Findings from the first simulation indicate that these materials can enhance storage capacity at reduced temperatures and volumes, albeit at a higher energy cost. The second simulation demonstrates that the hybrid model can improve storage capacity under constant working conditions. In conclusion, the two innovative strategies proposed in this thesis for advancing hydrogen storage technology show promise in increasing storage efficiency but require further optimization to reduce the system's energy consumption.