Automobile producer Toyota has developed an idea mannequin that explores how hydrogen gasoline generated whereas driving – “boil off gas” (vaporised hydrogen) – can be utilized, doubtlessly growing the effectivity of liquid hydrogen as an engine gas. The corporate is in search of companions to tackle the problem of creating the expertise collectively.
The idea was showcased final weekend on the ultimate spherical of the 2024 ENEOS Tremendous Taikyu race collection in Japan, the place the sector included a GR Corolla working on liquid hydrogen. Toyota will proceed to make use of the difficult world of motorsports to refine its vehicles and the talents and skills of individuals, along with its companions, to attain carbon neutrality.
The expertise rules
Liquid hydrogen has the next density than gaseous hydrogen, however whereas this implies a larger quantity may be saved in a tank of the identical capability, it presents the problem of “boil-off”. This can be a downside for all liquid hydrogen techniques, the place the gas saved within the tank evaporates as a result of pure warmth getting into from the skin. Till now, the boil-off gasoline generated within the tank whereas driving has been launched into the environment with out getting used.
The brand new idea mannequin reveals how the boil-off gasoline is perhaps used. Though nonetheless within the idea stage, this expertise might enhance the vitality effectivity of the complete liquid hydrogen system by recovering and utilizing the boil-off gasoline as vitality.
Reusing boil-off gasoline as gas
Toyota is engaged on the event of expertise to supply reusable gas by sending boil-off gasoline launched from liquid hydrogen within the tank to a self-pressuriser – a tool that will increase strain with out counting on exterior vitality. The boil-off gasoline may be transformed again to usable hydrogen gas for the engine by making use of strain, however growing the strain sufficiently normally requires vitality, similar to electrical energy. The self-pressuriser featured within the Toyota idea makes use of the strain of the boil-off gasoline to extend strain by two to 4 occasions, enough to supply reusable gas with out utilizing extra vitality.
Producing electrical energy with boil-off gasoline
In the course of the pressurisation course of, a specific amount of surplus boil-off gasoline continues to be launched. That is fed right into a small Toyota gas cell stack, the place it produces electrical energy via a chemical response. The electrical energy generated can be utilized to energy elements such because the liquid hydrogen pump. If realised, it is going to be doable to make use of boil-off gasoline to supply supplementary electrical energy equal to the quantity generated by the alternator, resulting in an enchancment in vitality effectivity.
Secure launch of surplus boil-off gasoline
Boil-off gasoline that isn’t used within the electrical energy technology course of is transformed into water vapour via a catalyst and safely launched exterior the car.
