The storage of hydrogen for its use as an energy carrier is one of the most critical aspects in the decarbonization of the transport sector. The objective of this project is therefore to develop a new hydrogen storage system based on solid-state absorption in metal hydrides, for both mobile and stationary applications.

The project features multiple innovative elements from technological, industrial, and environmental perspectives. In particular, the project will focus on identifying the optimal tank configuration for different applications which, combined with an advanced integrated thermal management system, will provide an efficient, cost-effective, and safe technical solution. To this end, MHYMOST will promote an innovative design methodology based on the principles of modularity and scalability, enabling the implementation and integration of the new hydrogen storage solution in various types of transport vehicles with different purposes, as well as in refueling stations. Among the types of vehicles targeted by the proposed technology are: i) road vehicles for passenger transport in urban areas, ii) industrial vehicles for handling and transporting goods, particularly port tractors used for loading and unloading operations from ships, iii) buses, iv) various types of material handling vehicles, such as forklifts, v) large vessels in the field of maritime mobility. In particular, one of MHYMOST’s key goals is to design and develop an integrated thermal management system for metal hydride tanks, capable of ensuring proper system operation and enabling reduced refueling times.

The MHYMOST project also addresses the pressing need to initiate a decarbonization process, particularly in the maritime and port sectors, where diversifying energy sources and increasing efficiency are among the key challenges in the coming years. By developing advanced energy technologies based on the use of hydrogen, the MHYMOST project fosters innovation both in terms of new products—arising from the conversion of transport vehicles currently powered by conventional internal combustion engines—and in terms of new models for managing energy needs in port facilities. These advancements stem from the safe, cost-effective, and efficient storage of hydrogen within refueling stations in port areas, offering significant benefits in reducing CO₂ emissions and air pollution. Indeed, one of the ambitions of this project is to initiate the steps toward using hydrogen as an alternative fuel in the maritime sector, demonstrating the feasibility and applicability of hydrogen technologies in a context where they can clearly address the need for increased energy efficiency and reduced pollution.

MHYMOST includes testing, in a controlled environment as close as possible to real-world conditions, of innovative metal hydride tanks for hydrogen storage. These tanks feature high energy density and advanced filling/discharging (adsorption and desorption) characteristics, aligned with those typically found in conventional fossil fuel tanks. This project, drawing on the experience gained from previous research and development initiatives in which the participating entities have been involved, as well as from their ongoing research activities, aims to achieve a Technology Readiness Level (TRL) between 4 and 6. In particular, the MHYMOST project plans to develop and test two prototypes both in a laboratory setting and in an operational environment.

The first metal hydride tank prototype will be developed for large-scale storage systems, intended for both stationary applications and onboard use in ships. The storage capacity of each module will be designed to enable systems capable of storing up to approximately 500 kg of hydrogen. Each module will consist of multiple cylindrical tanks, similar in shape to the most common compressed gas tanks.

The project will be conducted by means of experimental procedures and numerical modeling, for innovative metal hydride tanks for hydrogen storage, with high energy density, and with advanced absorption/desorption characteristics.

The thermal management system must be capable of adequately supplying heat during the endothermic desorption of hydrogen from the metal hydrides. Moreover, in order to achieve short refueling times for an onboard metal hydride tank, the project envisions the implementation of an innovative system that, by connecting the two tanks, can effectively harness the reaction heat to simultaneously heat the refueling station tank and cool the onboard vehicle tank.