The world’s first ship powered by solid hydrogen has been developed in the Netherlands. The Neo Orbis, a small passenger vessel measuring around 20 meters in length, is being built as part of the European H2Ships project. The ship will transport tourists through the canals of Amsterdam and the harbor area between Amsterdam and Ijmuiden. The Neo Orbis is powered by a fuel cell system that provides electricity for its electric propulsion. In addition, there are two batteries on board, each with a capacity of 25 kilowatt-hours.
What sets the Neo Orbis apart is that it stores hydrogen as a solid compound, rather than in a pressurized gas tank. The hydrogen is stored on board as sodium borohydride (NaBH4). To release the hydrogen for use in the fuel cell, the powdered sodium borohydride is mixed with high-purity water and a stabilizer. The resulting solution reacts with a catalyst, releasing the bound hydrogen and producing heat that is used to heat the ship. In a later development stage, a heat storage system will be installed to capture unused heat for later use.
The Neo Orbis is being built by the Dutch shipyard Next Generation Shipyards, and the first test runs are scheduled for the summer of 2023. According to project leaders, using sodium borohydride as a fuel has significant advantages over gaseous hydrogen. It does not need to be cooled or pressurized for storage, and its ignition point is much higher, making the system safer. The sodium metaborate (NaBO2) left over from the reaction can be recycled into new fuel by reacting it with hydrogen, although this process requires processing on land.
