06-03-2025 - Lecture Hall E

PhD presentation

Circular Bunkering for Maritime Vessels using Sodium Borohydride

Marcel van Benten

Solid hydrogen carriers, such as sodium borohydride (NaBH4), present a promising alternative for hydrogen fuel due to their favourable energy density compared to liquid and compressed hydrogen. When NaBH4 is used as fuel, a spent fuel—sodium metaborate—is formed, which must be stored on the vessel for the remainder of the voyage and later regenerated (e.g., through ball-milling) at the destination port, effectively creating a circular fuel economy.
One key challenge in implementing solid hydrogen carriers is that granular materials, unlike liquids, exhibit very different flow behaviours. While liquid fuels flow easily and can be handled with established infrastructure, granular fuels like sodium borohydride and sodium metaborate have unique characteristics, such as internal friction, cohesion, and wall friction, that can significantly affect their flowability and handling. Understanding these mechanical properties is crucial for designing efficient storage and handling systems.
To address this, we have conducted various experiments to determine the relevant mechanical properties of NaBH4. Using the obtained experimental data, the Discrete Element Method (DEM) is used to develop numerical models to mimic the flow behaviour, as illustrated in the figure above. Ultimately, the combination of experiments and simulations will provide the necessary knowledge to propose design requirements for the storage and handling equipment required to realise the circular fuel economy with NaBH4.

06-03-2025 - Lecture Hall E

PhD presentation

Methanol reforming to hydrogen in maritime applications and beyond

Bojan Grenko

The relevance of methanol in shipping applications is steadily increasing due to stringent maritime emission restrictions. Besides in internal combustion engines, methanol can also be used as hydrogen carrier for fuel cell applications, creating a path for continuous emission decrease and making it more future resilient. The emergent research topic from this outlook is purposing of methanol-to-hydrogen systems for transient operation, characteristic in transport applications. As such systems are currently operated in steady state in chemical processing plants, the challenge starts at defining the suitable tools and methods for unsteady analyses. Present research concludes, through numerical simulation, that the unsteady methanol reforming reactor operation heavily depends on the utilized reactor heating method.
As we wait validation for laboratory scale reactor currently under construction, this talk also reflects on research motivation, research convenience for hydrogen related technologies caused by the maritime sector, and application of conclusions beyond the maritime industry.