Iwatani has agreed to collaborate with Mitsubishi Fuso Truck and Bus (“MFTBC”) in developing liquid hydrogen refueling technology for FC trucks. A memorandum of understanding was signed on May 21.

The two companies will further develop a new filling technology called subcooled liquid hydrogen filling technology. The technology was originally developed by Daimler Truck, which is MFTBC’s parent company, and Linde Engineering. Liquid hydrogen pressurized by a pump is filled into a liquid hydrogen tank installed on the vehicle. The boil off gas in the tank is re-liquefied by the pressurized liquid hydrogen, making it possible to fill the on-board tank with liquid without releasing the boil off gas. Generally, when rapidly filling an FCV’s onboard tank with liquid hydrogen, it is necessary to remove the boil off gas remaining in the tank. The unique feature of this subcooled filling method is that it allows liquid hydrogen to be filled without removing the boil off gas. Discussions are underway to make this technology an ISO standard.

Daimler Truck has developed a large Mercedes-brand FC truck prototype, called the GenH2 Truck, and has conducted demonstrations at customer sites since 2024. In these demonstrations, it is said that subcooled filling is being used.

MFTBC says hydrogen fuel is an important means to achieve carbon neutrality for trucks that transport heavy goods, particularly for long-distance transportation. Traditionally, vehicles were filled with high-pressure hydrogen gas (at 82 MPa), but using liquid hydrogen has the advantage of allowing the vehicles to travel longer distances. In addition, when filling hydrogen tanks, liquid hydrogen consumes less energy in the compression process compared with high-pressure hydrogen gas and can thereby contribute to reducing the operating costs of hydrogen filling stations.

Iwatani and MFTBC will continue R&D into subcooled hydrogen filling, which is the optimal method for filling large commercial FC trucks with hydrogen, and will also consider regulating the technology and commercializing it.