Ammonia as a Hydrogen Energy Carrier and Its Application to Internal Combustion Engines

Abstract

Anhydrous liquid ammonia offers a considerable advantage over hydrogen in that it has a large volumetric energy density. The total amount of energy that would be expended for its production and transportation to consumers is estimated to be less than that for liquid hydrogen transportation, even if some lower heating value is lost through chemical conversion. From a storage viewpoint, the advantages of energy density would be particularly beneficial to automobiles carrying traveling energy with them. Ammonia has some attractive thermodynamic properties for internal combustion engines as well as higher ignition temperature to mitigate knocking. Although ammonia has a low flame velocity for use in internal combustion engines, an auto-thermal-cracker providing hydrogen helps the engine to run stably. A challenge in SIP program is promoting combustion to achieve as high combustion efficiency as current gasoline combustion with minimum auxiliary fuel.