Explosion characteristics and suppression of hybrid Mg/H2 mixtures

Abstract In the production of magnesium hydride, hybrid Mg/H2 mixtures has a risk of explosion; therefore, systematic experiments were conducted to study its explosion characteristics and suppression. According to the results, the maximum rate of explosion pressure rise (dP/dt)max of hybrid Mg/H2 mixtures was more the twice than that of pure Mg. Five common explosion suppressants were individually added to hybrid Mg/H2 mixtures to inhibit dust explosion. Na2CO3, CaCO3, and (NH4)2HPO3 exhibited great inhibitory abilities for hybrid Mg/H2 mixtures explosion; however, melamine–cyanurate acid (MCA) and melamine polyphosphate (MPP) could stimulate the explosion. The mechanisms underlying MCA and MPP promotion of the hybrid Mg/H2 mixtures explosion were determined, namely the high concentration of flammable gases, such as ammonia, released after their thermal decomposition. These gases can ignite and intensify the explosion of hybrid Mg/H2 mixtures. This study provides a reference for reducing the risk in the H2 storage system of Mg.