Compressed hydrogen production via reaction between liquid ammonia and alkali metal hydride

摘要

Ammonia NH_3 is recognized as one of the attractive hydrogen H_2 carriers because it has a high hydrogen content of 18 mass% and it is easily liquefied under about 1 MPa of pressure at a room temperature. NH_3 can react with alkali metal hydrides and generate H_2 even at room temperature, resulting that metal amides are formed as reaction products. The H_2 generation is exothermic reaction, and it is not effectively prevented by H_2 partial pressure in a closed system as thermodynamic properties. In this work, we demonstrated the production of compressed H_2 by the reaction between liquid NH_3 and lithium hydride LiH in a closed pressure vessel, where liquid NH_3 would realize better kinetic properties for the reaction with metal hydride than gaseous NH_3. Actually, more than 12 MPa H_2 was obtained within several hours.