Toyota launches a new liquid hydrogen system

The technology is expected to improve the energy efficiency of the entire liquid hydrogen system by recovering and using boil-off gas as energy.

Toyota is advancing hydrogen-powered vehicle technology with a new liquid hydrogen system designed to enhance efficiency by capturing and reusing boil-off gas as fuel. The system, showcased in the GR Corolla H2 Concept in 2023, features a "self-pressurizer" that leverages boil-off gas pressure to improve engine performance without additional energy input.

Hydrogen, typically a gas at room temperature, must be stored at extremely low temperatures to remain in liquid form. Toyota’s system keeps hydrogen at -253 degrees Celsius during filling and storage, a process that prevents boiling but inevitably produces some boil-off gas. The self-pressurizer addresses this challenge by increasing pressure by two to four times, converting the gas into reusable fuel. Toyota also plans to integrate a small fuel cell to further utilize any remaining boil-off gas, potentially powering the hydrogen pump motor for greater efficiency.

This innovation was unveiled during the Super Taikyu Series 2024 race, highlighting Toyota's efforts to tackle the complexities of liquid hydrogen storage and handling. Liquid hydrogen systems are technically demanding, particularly regarding storage and the performance of hydrogen pumps, which are considered the most failure-prone components in hydrogen systems, according to Dr. Jacob Leachman, a professor at Washington State University.

Dr. Leachman noted that Toyota’s approach represents a significant advancement. By using part of the system's cold energy for compression, Toyota has addressed a critical challenge in developing cryogenic hydrogen vehicles, potentially setting a new standard for the industry.