Hrein Energy Inc., a Japan-based developer of hydrogen storage systems based on organic hydrides, has successfully field-tested an on-board version of its storage system to produce a hydrogen stream for use with gasoline in an automobile combustion engine. Hrein is targeting its system for eventual use with fuel-cell vehicles, among other applications.
The cooperative research project included Professor Emeritus Masaru Ichikawa of Hokkaido University, the developer of the organic hydride system, along with Futaba Industrial Co. and Ito Racing Service Co.
Organic hydrides are liquids under atmospheric temperature and pressure, yet offer relatively high hydrogen content: between 6-8 wt.%. An example of the reaction is:
Methylcyclohexane C7H14 ←→ Toluene C7H8 + 3H2
Because the organic hydrides are liquids (not to be confused with liquefied hydrogen), the existing fuel storage, transportation and refueling infrastructure could basically be maintained were the liquids applied to transportation.
Organic chemical hydrides can freely produce and absorb H2 gas by catalytic reaction under mild conditions. Hrein developed a spray pulse reactor that feeds the reactant (the organic hydride liquid) to the hot catalyst surface as atomized liquid.
The company obtained its highest hydrogen production rate by using highly heat conducting supporting materials (thin Al2O3 layer on aluminum plate). Hrein Energy and the others packaged this system in the form of a small cylindrical reactor for recovering hydrogen from the organic hydride. Made of aluminum, the reactor is 45cm tall and 15cm in diameter and is heated by the engine’s exhaust.
Hrein Energy plans to test the system on a compact car within the year.
Separately, at the recent 234th meeting of the American Chemical Society, Robert Crabtree from Yale presented his work on developing catalysts that could enable the use of hydrogen carried in a liquid fuel for transportation use.
Hrein Energy Hydrogen Storage and Supply System
R. Crabtree, Odile Eisenstein, and Eric Clot, “Hydrogen storage in azaheterocyclic organic liquids” (ACS 234 FUEL 103)