Developing a Free-Piston Expander for Hydrogen Cooling to Improve Cost and Efficiency of Hydrogen Vehicle Fueling Infrastructure

The U.S. Department of Energy is providing funding to GTI Energy to develop a new technology to drastically improve the cost and efficiency of hydrogen vehicle fueling infrastructure.

The innovative free-piston expander eliminates the need for a hydrogen pre-cooling unit and flow control valve that prevent extremely high temperatures from occurring in the vehicle during fueling.

Using an efficient expansion device to reduce pressure allows the gas to cool down. A free-piston expander is ideally suited for this task due to its proven efficiency and its capability to adjust pressure ratio over the course of the fill. Low maintenance cost is also a key benefit of this technology as there is only one moving part.