METHOD AND DEVICE FOR STORING AND DELIVERING AMMONIA FROM A SOLID AMMONIA STORAGE MEDIUM

摘要

Solid metal ammine complexes are applied for safe and high-density storage of ammonia to be released for use as reducing agent in selective catalytic reduction of NO_x in exhaust gases or as an energy carrier for fuel cell applications. The compositional formula of the metal ammine complexes is M(NH₃)_nX_z, where M^z+ represents one or more metal ions capable of binding ammonia, X represents one or more anions, n is the coordination number (from 2 to 12), and z the valency of the metal ion (and thus the total number of compensating anion charges). Ammonia is released by controlled dosing of water into the storage container whereby ammonia is released because water replaces ammonia on the active sites capable of binding ammonia. Consequently, ammonia can be released without applying a normal thermal desorption of ammonia and the operating temperature of the system is reduced as well as the energy needed for releasing ammonia.